Weight References

One of the principles of size acceptance is that weight loss is not always beneficial, that it often leads to weight cycling and disordered eating behaviors, and that weight instability may be more harmful than a higher but more stable weight, especially if accompanied by good fitness.

Here is a quick list of abstracts of various studies related to the chances of long-term weight loss maintenance, the risks of weight loss and weight cycling, and the Health At Every Size® alternative. After each citation is a PubMed ID Number (PMID), which has a link to the study's abstract.

If you run across other studies you think I should add, you can email the abstract (in the body of the email, not as an attachment) to me at kmom AT plus-size-pregnancy dot ORG and I'll review it for addition.

References

General Weight Loss Overviews

 Am Psychol. 2007 Apr;62(3):220-33. Medicare's search for effective obesity treatments: diets are not the answer. Mann T, Tomiyama AJ, Westling E, Lew AM, Samuels B, Chatman J.  PMID: 17469900  Full text at:
The prevalence of obesity and its associated health problems have increased sharply in the past 2 decades. New revisions to Medicare policy will allow funding for obesity treatments of proven efficacy. The authors review studies of the long-term outcomes of calorie-restricting diets to assess whether dieting is an effective treatment for obesity. These studies show that one third to two thirds of dieters regain more weight than they lost on their diets, and these studies likely underestimate the extent to which dieting is counterproductive because of several methodological problems, all of which bias the studies toward showing successful weight loss maintenance. In addition, the studies do not provide consistent evidence that dieting results in significant health improvements, regardless of weight change. In sum, there is little support for the notion that diets lead to lasting weight loss or health benefits.
Can Fam Physician. 2012 May;58(5):517-23. The downside of weight loss: realistic intervention in body-weight trajectory. Bosomworth NJ.   PMID: 22586192  Free full text at:
OBJECTIVE: To explore the reasons why long-term weight loss is seldom achieved and to evaluate the consequences of various weight trajectories, including stability, loss, and gain. QUALITY OF EVIDENCE: Studies evaluating population weight metrics were mainly observational. Level I evidence was available to evaluate the influence of weight interventions on mortality and quality of life. MAIN MESSAGE: Sustained weight loss is achieved by a small percentage of those intending to lose weight. Mortality is lowest in the high-normal and overweight range. The safest body-size trajectory is stable weight with optimization of physical and metabolic fitness. With weight loss there is evidence for lower mortality in those with obesity-related comorbidities. There is also evidence for improved health-related quality of life in obese individuals who lose weight. Weight loss in the healthy obese, however, is associated with increased mortality. CONCLUSION: Weight loss is advisable only for those with obesity-related comorbidities. Healthy obese people wishing to lose weight should be informed that there might be associated risks. A strategy that leads to a stable body mass index with optimized physical and metabolic fitness at any size is the safest weight intervention option.
Nutr J. 2010 Jul 20;9:30. Validity of claims made in weight management research: a narrative review of dietetic articles. Aphramor L. PMID: 20646282  Full text at:  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2916886/
BACKGROUND: The best available evidence demonstrates that conventional weight management has a high long-term failure rate. The ethical implications of continued reliance on an energy deficit approach to weight management are under-explored. METHODS: A narrative literature review of journal articles in The Journal of Human Nutrition and Dietetics from 2004 to 2008. RESULTS: Although the energy deficit approach to weight management has a high long-term failure rate it continues to dominate research in the field. In the current research agenda, controversies and complexities in the evidence base are inadequately discussed, and claims about the likely success of weight management misrepresent available evidence. CONCLUSIONS: Dietetic literature on weight management fails to meet the standards of evidence based medicine. Research in the field is characterised by speculative claims that fail to accurately represent the available data. There is a corresponding lack of debate on the ethical implications of continuing to promote ineffective treatment regimes and little research into alternative non-weight centred approaches. An alternative health at every size approach is recommended.
Int J Obes (Lond). 2005 Oct;29(10):1153-67. Systematic review of long-term weight loss studies in obese adults: clinical significance and applicability to clinical practice. Douketis JD, Macie C, Thabane L, Williamson DF. PMID: 15997250

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BACKGROUND: Obesity is a common health problem that requires a long-term care approach. We systematically reviewed long-term (> or =2 y) studies investigating dietary/lifestyle, pharmacologic, and surgical weight loss methods to assess (1) weight loss efficacy, defined by absolute weight loss and the proportion of subjects with > or =5% weight loss, (2) effects of weight loss on cardiovascular risk factors, and (3) applicability of findings from studies to everyday clinical practice. METHODS: The MEDLINE, HealthSTAR, and the Cochrane Controlled Trials databases were searched for studies investigating the long-term efficacy of weight loss methods in overweight and obese adults. Data were extracted for (i) weight loss after 1 y (pharmacologic studies only), 2 y, 3 y, and 4 y, (ii) proportion of subjects with > or =5% weight loss at the end of follow-up, and (iii) changes (end-of follow-up minus baseline values) in blood lipids, fasting blood glucose, and systolic and diastolic blood pressure. RESULTS: Dietary/lifestyle therapy provides <5 kg weight loss after 2-4 y, pharmacologic therapy provides 5-10 kg weight loss after 1-2 y, and surgical therapy provides 25-75 kg weight loss after 2-4 y. Weight loss of > or =5% baseline weight is not consistently associated with improvements in cardiovascular risk factors and these benefits appear to be intervention specific and occur mainly in people with concomitant cardiovascular risk factors. Weight loss studies have methodologic limitations that restrict the applicability of findings to unselected obese people assessed in everyday clinical practice. These limitations include an inadequate study duration, large proportions of subjects lost to follow-up, a lack of an appropriate usual care group, and a lack of reporting of outcomes in high-risk subgroups. CONCLUSIONS: Dietary/lifestyle and pharmacologic weight loss interventions provide modest weight loss, and may improve markers of cardiovascular risk factors although these benefits occur mainly in patients with cardiovascular risks. Studies investigating weight loss have methodologic limitations that restrict the applicability of findings to obese patients assessed in clinical practice.
Med Sci Sports Exerc. 1999 Aug;31(8):1129-34. How effective are traditional dietary and exercise interventions for weight loss?  Miller WC.   PMID: 10449014
Health care professionals have used restrictive dieting and exercise intervention strategies in an effort to combat the rising prevalence of obesity in affluent countries. In spite of these efforts, the prevalence of obesity continues to rise. This apparent ineffectiveness of diet and exercise programming to reduce obesity has caused many health care providers, obesity researchers, and lay persons to challenge the further use of diet and exercise for the sole purpose of reducing body weight in the obese. The purposes of this paper were to examine the history and effectiveness of diet and exercise in obesity therapy and to determine the best future approach for health promotion in the obese population. A brief survey of the most popular dieting techniques used over the past 40 yr shows that most techniques cycle in and out of popularity and that many of these techniques may be hazardous to health. Data from the scientific community indicate that a 15-wk diet or diet plus exercise program produces a weight loss of about 11 kg with a 60-80% maintenance after 1 yr. Although long-term follow-up data are meager, the data that do exist suggest almost complete relapse after 3-5 yr. The paucity of data provided by the weight-loss industry has been inadequate or inconclusive. Those who challenge the use of diet and exercise solely for weight control purposes base their position on the absence of weight-loss effectiveness data and on the presence of harmful effects of restrictive dieting. Any intervention strategy for the obese should be one that would promote the development of a healthy lifestyle. The outcome parameters used to evaluate the success of such an intervention should be specific to chronic disease risk and symptomatologies and not limited to medically ambiguous variables like body weight or body composition.
Clinical Psychology Review. 1991;11(6):729-780. doi: 10.1016/0272-7358(91)90128-H Confronting the failure of behavioral and dietary treatments for obesity. Garner, David M.; Wooley, Susan C.
Questions the appropriateness of behavioral and dietary treatments of obesity in light of overwhelming evidence that they are ineffective in producing lasting weight loss. The stigmatization of obesity, the overstatement of health risks, and the pervasive influence of the lucrative diet industry have maintained public demand for dietary treatment. However, much evidence suggests that maintenance of high but stable weight is safer than weight fluctuation. Alternative nondieting approaches aimed at improving the physical and psychological well-being of the obese individual should be given priority over dietary treatments as a subject of research.
Long-Term Success of Weight Loss

Int J Obes Relat Metab Disord. 2000 Sep;24(9):1107-10. Can anyone successfully control their weight? Findings of a three year community-based study of men and women. Crawford D, Jeffery RW, French SA.   PMID: 11033978
This study examined the prevalence, distribution and correlates of successful weight loss and successful weight maintenance over three years in a community-based sample of 854 subjects aged 20-45 at baseline. More than half (53.7%) of the participants in the study gained weight within the first twelve months, only one in four (24.5%) successfully avoided weight gain over three years, and less than one in twenty (4.6%) lost and maintained weight successfully. The findings underscore the importance of current public health efforts to prevent weight gain, and suggest that without much greater efforts to promote and support weight control the prevalence of obesity will continue to rise.
J Nutr Educ Behav. 2005 Jul-Aug;37(4):203-5. The National Weight Control Registry: a critique. Ikeda J, Amy NK, Ernsberger P, Gaesser GA, Berg FM, Clark CA, Parham ES, Peters P.   PMID: 16029691
This article is a critique of the claim that the National Weight Control Registry provides data showing that a significant number of adults in the United States have achieved permanent weight loss. We believe that promoting calorie-restricted dieting for the purpose of weight loss is misleading and futile. We advocate the adoption of a health-at-every-size (HAES) approach to weight management, focusing on the achievement and maintenance of lifestyle changes that improve metabolic indicators of health.
J Am Diet Assoc. 2005 May;105(5 Suppl 1):S63-6. Weight maintenance: what's missing? Hill JO, Thompson H, Wyatt H.   PMID: 15867898
Obesity has reached epidemic proportions in the United States, but there are few proven strategies for either preventing further weight gain or producing permanent weight loss. Our first priority should be to prevent the gradual weight gain experienced by much of the population. Although this will require less behavior change than producing and maintaining weight loss, helping Americans make and sustain the behavior changes needed to prevent gradual weight increases will be challenging. Because approximately 65% of Americans are already overweight or obese, we must also develop effective strategies to help achieve and maintain an amount of weight loss that improves their health and quality of life. Our real challenge is not in helping people lose weight but in helping them keep it off. Many programs have been shown to produce weight loss but few, if any, have been successful in maintenance of weight loss. Our challenge is in understanding how to help people keep off the weight they can lose in several ways.
Weight Cycling and Long-Term Weight Gain

Obes Res. 2004 Feb;12(2):267-74. Weight cycling and the risk of developing type 2 diabetes among adult women in the United States. Field AE, Manson JE, Laird N, Williamson DF, Willett WC, Colditz GA.  PMID: 14981219
OBJECTIVE: To assess the role of weight cycling independent of BMI and weight change in predicting the risk of developing type 2 diabetes. RESEARCH METHODS AND PROCEDURES: A six-year follow-up of 46,634 young and middle-aged women in the Nurses' Health Study II was conducted. Women who had intentionally lost > or = 20 lbs at least three times between 1989 and 1993 were classified as severe weight cyclers. Women who had intentionally lost > or = 10 lbs at least three times were classified as mild weight cyclers. The outcome was physician-diagnosed type 2 diabetes. RESULTS: Between 1989 and 1993, approximately 20% of the women were mild weight cyclers, and 1.6% were severe weight cyclers. BMI in 1993 was positively associated with weight-cycling status (p < 0.001). During 6 years of follow-up (1993 to 1999), 418 incident cases of type 2 diabetes were documented. BMI in 1993 had a strong association with the risk of developing diabetes. Compared with women with a BMI between 17 and 22 kg/m(2), those with a BMI between 25 and 29.9 kg/m(2) were approximately seven times more likely to develop diabetes, and those with a BMI > or = 35 kg/m(2) were 63 times more likely to be diagnosed with type 2 diabetes. After adjustment for BMI, neither mild (relative risk = 1.11, 95% confidence interval, 0.89 to 1.37) nor severe (relative risk = 1.39, 95% confidence interval, 0.90 to 2.13) weight cycling predicted risk of diabetes. DISCUSSION: Weight cycling was strongly associated with BMI, but it was not independently predictive of developing type 2 diabetes.
Int J Obes Relat Metab Disord. 2002 Jul;26(7):969-72. Prevalence and correlates of large weight gains and losses. Jeffery RW, McGuire MT, French SA.  PMID: 12080451  Free full text at:
OBJECTIVE: To examine the prevalence and correlates of large weight gains and losses over a 3 y period in a heterogeneous population of participants in a study of weight gain prevention. DESIGN AND MEASURES: Analyses based on a cohort of 823 participants in a weight gain prevention study whose weight was measured on at least two of four annual examinations. RESULTS: Weight gains and losses of >or=5% body weight over 1 y were observed in 9.3 and 15% of the population, respectively. Weight gains among those initially losing weight were significantly greater (3.9 kg) than among those experiencing stable weight (0.8 kg) or a large weight gain (1.5 kg) over the following 2 y. Cumulative weight changes over 3 y were -2.6, 1.0 and 7.6 kg among large loss, weight stable and large gain groups, respectively. Large weight loss was more common in smokers, large gains were more common in younger people and in those with a more extensive weight loss history, and stable weight was observed more often in individuals with less extensive histories of weight loss. CONCLUSION: The high prevalence of large short-term weight gains and losses in this heterogeneous population, their apparent resistance to short-term reversal, and the strength of their relationship to longer-term weight trends suggest that rapid weight change over relatively short time intervals is a phenomenon that deserves more research attention. Short periods of rapid weight gain may contribute importantly to rapidly rising obesity rates.
J Am Diet Assoc. 2007 Mar;107(3):448-55. Why does dieting predict weight gain in adolescents? Findings from project EAT-II: a 5-year longitudinal study. Neumark-Sztainer D, Wall M, Haines J, Story M, Eisenberg ME.   PMID: 17324664 
OBJECTIVE: Dieting has been found to predict weight gain in adolescents, but reasons for this association remain unclear. This study aimed to explore potential mechanisms by which dieting predicts weight gain over time in adolescents. DESIGN: Population-based, 5-year longitudinal study. PARTICIPANTS: Adolescents (n=2,516) from diverse ethnic and socioeconomic backgrounds who completed Project EAT (Eating Among Teens) surveys in 1999 (Time 1) and 2004 (Time 2). MAIN OUTCOME MEASURE: Body mass index (BMI) change over 5 years. STATISTICAL ANALYSIS: Multiple regressions were used to examine associations between Time 1 dieting and Time 2 binge eating, breakfast consumption, fruit and vegetable intake, and physical activity. Associations were then examined between these behaviors and BMI change. Finally, to test for mediating effects, associations between dieting and BMI change were examined with and without the inclusion of these behaviors, and regression coefficients were compared. RESULTS: In female adolescents, dieting predicted increased binge eating (P<0.001) and decreased breakfast consumption (P=0.030). In male adolescents, dieting predicted increased binge eating (P<0.001), decreased physical activity (P=0.006), and a trend toward decreased breakfast consumption (P=0.064). These behaviors were also associated with increases in BMI. The association between dieting and BMI increase was weakened, but still remained significant, after binge eating, breakfast consumption, fruit/vegetable intake, and physical activity were included in the model being tested. Thus, the longitudinal association between dieting and BMI increase was partially mediated by these behaviors. CONCLUSIONS: In part, dieting may lead to weight gain via the long-term adoption of behavioral patterns that are counterproductive to weight management.
Clin Nutr. 2011 Dec;30(6):718-23. doi: 10.1016/j.clnu.2011.06.009. Epub 2011 Jul 20. Weight cycling is associated with body weight excess and abdominal fat accumulation: a cross-sectional study. Cereda E, Malavazos AE, Caccialanza R, Rondanelli M, Fatati G, Barichella M. PMID: 21764186

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BACKGROUND & AIMS: To investigate the association between history of multiple weight loss diets followed by weight regain, namely weight cycling (WCy), and both body weight excess and abdominal fat accumulation. METHODS: A one-day cross-sectional survey ("Obesity-Day") including 914 participants (605F:309M). Anthropometric variables (body mass index [BMI], waist circumference [WC] and waist-to-height ratio [WtHR]), covariates and WCy (≥ 5 intentional weight loss episodes of ≥ 5 kg followed by rapid return to pre-diet or higher body weight) were assessed by a self-administered questionnaire, interview and physical examination. RESULTS: Data on central fat accumulation (by WC and WtHR) were available in a representative sub-group (n = 600). WCy was reported by 119 participants (13.0%) of total population and by 79 (13.2%) of those with available data on central fat accumulation. At multivariable linear regressions WCy was independently associated with higher BMI (P = .004), WC (P = .011) and WtHR (P = .008). Sensitivity analyses, performed after excluding those being on a diet at the time of assessment, confirmed these findings. CONCLUSIONS: A history of WCy appears related to body weight excess and abdominal fat accumulation. These findings support the importance of designing adequate weight loss programs to achieve long-term weight maintenance and to prevent undesirable and unhealthy weight accumulation.
Weight Cycling and Disease

Am J Epidemiol. 2007 Oct 1;166(7):752-9. Epub 2007 Jul 5. Body size, weight cycling, and risk of renal cell carcinoma among postmenopausal women: the Women's Health Initiative (United States). Luo J, Margolis KL, Adami HO, Lopez AM, Lessin L, Ye W; Women's Health Initiative Investigators. PMID: 17615089

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Although obesity is an established risk factor for renal cell carcinoma, the possible effect of central adiposity and long-term variation in weight has yet to be established. The authors studied 140,057 women aged 50-79 years enrolled in the Women's Health Initiative in the United States to examine the role of obesity, especially abdominal obesity, and weight cycling in relation to risk of renal cell carcinoma among postmenopausal women. Cox models were used to estimate relative risks and their corresponding 95% confidence intervals. During an average of 7.7 years of follow-up through September 12, 2005, a total of 269 incident cases of renal cell carcinoma were identified. Central adiposity, as indicated by waist-to-hip ratio, was an important risk factor for developing renal cell carcinoma (highest vs. lowest quartile: relative risk = 1.8, 95% confidence interval: 1.2, 2.5; p for trend = 0.0003). Moreover, women who had experienced weight cycling more than 10 times were at 2.6 times (95% confidence interval: 1.6, 4.2) increased risk compared with women whose weight was stable. Results add evidence that obesity, particularly central adiposity, is associated with an increased risk of renal cell carcinoma among postmenopausal women. Furthermore, they indicate that weight cycling is independently associated with further increased risk of this malignancy.
Arch Intern Med. 2006 Nov 27;166(21):2369-74. Weight cycling and risk of gallstone disease in men. Tsai CJ, Leitzmann MF, Willett WC, Giovannucci EL. PMID: 17130391

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BACKGROUND: The long-term effect of repeated intentional weight loss and weight regain on the risk of gallstone disease in men is not clear. METHODS: Participants in the Health Professionals Follow-up Study provided information on intentional weight loss during the previous 4 years in 1992. Weight cyclers were men who had intentional weight loss and weight regain. Men free of gallstone disease at baseline were followed from 1992 to 2002. On biennial questionnaires the participants reported newly diagnosed gallstone disease. RESULTS: During 264,760 person-years of follow-up we ascertained 1222 cases of symptomatic gallstones. We examined the effect of weight cycling on the risk of gallstone disease. The multivariate relative risk of weight cyclers, compared with weight maintainers, after adjusting for potential confounding variables, including body mass index, was 1.11 (95% confidence interval [CI], 0.94-1.31) in light cyclers, 1.18 (95% CI, 0.97-1.43) in moderate cyclers, and 1.42 (95% CI, 1.11-1.81) in severe cyclers. We further examined the effect of number of cycling episodes. Among weight cyclers, the relative risk associated with having more than 1 weight cycle, compared with weight maintainers, was 1.10 (95% CI, 0.88-1.37) in light cyclers, 1.28 (95% CI, 1.03-1.59) in moderate cyclers, and 1.51 (95% CI, 1.13-2.02) in severe cyclers. CONCLUSIONS: Our findings suggest that weight cycling, independent of body mass index, may increase the risk of gallstone disease in men. Larger weight fluctuation and more weight cycles are associated with greater risk.
Ann Intern Med. 1999 Mar 16;130(6):471-7. Long-term weight patterns and risk for cholecystectomy in women. Syngal S, Coakley EH, Willett WC, Byers T, Williamson DF, Colditz GA. PMID: 10075614

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BACKGROUND: Obesity and rapid weight loss in obese persons are known risk factors for gallstones. However, the effect of intentional, long-term, moderate weight changes on the risk for gallstones is unclear. OBJECTIVE: To study long-term weight patterns in a cohort of women and to examine the relation between weight pattern and risk for cholecystectomy. DESIGN: Prospective cohort study. SETTING: 11 U.S. states. PARTICIPANTS: 47,153 female registered nurses who did not undergo cholecystectomy before 1988. MEASUREMENTS: Cholecystectomy between 1988 and 1994 (ascertained by patient self-report). RESULTS: During the exposure period (1972 to 1988), there was evidence of substantial variation in weight due to intentional weight loss during adulthood. Among cohort patients, 54.9% reported weight cycling with at least one episode of intentional weight loss associated with regain. Of the total cohort, 20.1% were light cyclers (5 to 9 lb of weight loss and gain), 18.8% were moderate cyclers (10 to 19 lb of weight loss and gain), and 16.0% were severe cyclers (> or = 20 lb of weight loss and gain). Net weight gain without cycling occurred in 29.3% of women; net weight loss without cycling was the least common pattern (4.6%). Only 11.1% of the cohort maintained weight within 5 lb over the 16-year period. In the study, 1751 women had undergone cholecystectomy between 1988 and 1994. Compared with weight maintainers, the relative risk for cholecystectomy (adjusted for body mass index, age, alcohol intake, fat intake, and smoking) was 1.20 (95% CI, 0.96 to 1.50) among light cyclers, 1.31 among moderate cyclers (CI, 1.05 to 1.64), and 1.68 among severe cyclers (CI, 1.34 to 2.10). CONCLUSION: Weight cycling was highly prevalent in this large cohort of middle-aged women. The risk for cholecystectomy associated with weight cycling was substantial, independent of attained relative body weight.
J Hum Hypertens. 2005 Jan;19(1):61-7. Associations of short-term weight changes and weight cycling with incidence of essential hypertension in the EPIC-Potsdam Study. Schulz M, Liese AD, Boeing H, Cunningham JE, Moore CG, Kroke A. PMID: 15343355

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The aim of this study was to examine the relationships of short-term weight gain, weight loss, and weight cycling on the odds of developing hypertension. Normotensive middle-aged German men and women (n=12,362) of the European Prospective Investigation into Cancer and Nutrition-Potsdam Study were assigned to categories of 2-year short-term weight changes that were self-reported to have occurred prior to recruitment into the study (gain only, loss only, weight cycling, stable). After 2 years of follow-up after recruitment, 180 cases of incident essential hypertension were identified. In logistic regression models, odds ratios were estimated for the associations between short-term weight changes and risk of developing hypertension. Obesity status (BMI>or=30 or BMI<30 kg/m2) modified the associations between short-term weight change and incidence of diagnosed hypertension. Among obese individuals, short-term weight gain occurring during the 2 years prior to recruitment (OR=2.79, 95% CI 1.19-6.56), weight loss (OR=6.74, 95% CI 2.58-17.6) and weight cycling (OR=4.29, 95% CI 1.55-11.9) were strongly positively associated with incident hypertension, adjusted for age and gender, compared to obese individuals with short-term stable weight. No significant associations between short-term weight changes and risk of diagnosed hypertension were detected among non-obese individuals. Short-term weight changes appeared to present strong risk factors for developing hypertension among obese individuals. The effect seen for weight cycling supports the hypothesis that weight cycling increases the risk of hypertension. The finding for short-term weight loss may be explained by subsequent weight regain and needs further investigation.
Weight Loss, Weight Cycling and Mortality

*It should be noted that it is difficult to tease out the relationship between weight loss, weight cycling, and mortality.   Some studies indicate that weight loss is beneficial to longevity, the following studies suggest it is harmful, and other studies are less clear.  This may be because it's hard to disentangle the results of intentional weight loss from that which may happen as a result of disease.  Also, some researchers use some disingenuous statistical sleight of hand in order to show weight loss more favorably or weight cycling more benignly. Thus, the relationship between weight loss, weight cycling, and mortality has yet to be clearly delineated.

J Intern Med. 2002 Jul;252(1):70-8. The enigma of increased non-cancer mortality after weight loss in healthy men who are overweight or obese. Nilsson PM, Nilsson JA, Hedblad B, Berglund G, Lindgärde F.   PMID: 12074741
OBJECTIVE: To study effects on non-cancer mortality of observational weight loss in middle-aged men stratified for body mass index (BMI), taking a wide range of possible confounders into account. DESIGN: Prospective, population based study. SETTING: Male population of Malmö, Sweden. PARTICIPANTS: In all 5722 men were screened twice with a mean time interval of 6 years in Malmö, southern Sweden. They were classified according to BMI category at baseline (<21, 22-25, overweight: 26-30, and obesity: 30+ kg m(-2)) and weight change category until second screening (weight stable men defined as having a baseline BMI +/- 0.1 kg m(-2) year-1 at follow-up re-screening). MAIN OUTCOME MEASURES: Non-cancer mortality calculated from national registers during 16 years of follow-up after the second screening. Data from the first year of follow-up were excluded to avoid bias by mortality caused by subclinical disease at re-screening. RESULTS: The relative risk (RR; 95% CI) for non-cancer mortality during follow-up was higher in men with decreasing BMI in all subgroups: RR 2.64 (1.46-4.71, baseline BMI <21 kg m(-2)), 1.39 (0.98-1.95, baseline BMI 22-25 kg m(-2)), and 1.71 (1.18-2.47, baseline BMI 26+ kg m(-2)), using BMI-stable men as reference group. Correspondingly, the non-cancer mortality was also higher in men with increasing BMI, but only in the obese group (baseline BMI 26+ kg m(-2)) with RR 1.86 (1.31-2.65). In a subanalysis, nonsmoking obese (30+ kg m(-2)) men with decreased BMI had an increased non-cancer mortality compared with BMI-stable obese men (Fischer's test: P=0.001). The mortality risk for nonsmoking overweight men who increased their BMI compared with BMI-stable men was also significant (P=0.006), but not in corresponding obese men (P=0.094). CONCLUSIONS. Weight loss in self-reported healthy but overweight middle-aged men, without serious disease, is associated with an increased non-cancer mortality, which seems even more pronounced in obese, nonsmoking men, as compared with corresponding but weight-stable men. The explanation for these observational findings is still enigmatic but could hypothetically be because of premature ageing effects causing so-called weight loss of involution.
Int J Obes (Lond). 2010 Apr;34(4):760-9. doi: 10.1038/ijo.2009.274. Epub 2010 Jan 12. Combined effects of weight loss and physical activity on all-cause mortality of overweight men and women. Østergaard JN, Grønbaek M, Schnohr P, Sørensen TI, Heitmann BL. PMID: 20065967
OBJECTIVE: To estimate the excess deaths associated with weight loss in combination with leisure time physical activity among overweight or obese people. DESIGN: Prospective cohort study. SUBJECTS: In two consecutive examinations in 1976-1978 and 1981-1983, 11 135 people participated in the Copenhagen City Heart Study. Of these, 3078 overweight or obese participants lost weight or remained weight stable from 1976-1978 to 1981-1983, and were without pre-existing diagnosis of diabetes, stroke, ischaemic heart disease or cancer in 1981-1983. They were followed up until 2007 in the Danish Civil Registration System, with a <0.2% loss to follow-up only. MEASUREMENTS: The following measurements were taken: body mass index (BMI) and physical activity in 1976-1978 and 1981-1983 and hazard ratio (HR) of mortality during 53 976 person-years of follow-up. RESULTS: Of the initially overweight or obese subjects who either lost weight or remained weight stable, 2060 died. Overall, weight loss was associated with excess mortality when compared with weight stability. Weight loss was associated with a higher mortality among those who became physically inactive, compared with those who remained active while losing weight (men: HR 2.25, 95% confidence interval 1.31-3.84; women: 1.43, 1.07-1.91). However, losing weight while remaining physically active was still associated with excess mortality when compared with those who were weight stable and initially active (men: 1.72, 1.27-2.34; women: 1.57, 1.06-2.31). Among those who remained physically inactive, weight loss seemed associated with excess mortality when compared with weight loss among those who became active, although not statistically significant (men: 2.00, 0.94-4.29; women: 1.40, 0.82-2.39). Finally, weight loss among those who became physically active was not associated with excess mortality when compared with those who were weight stable and initially inactive (men: 1.12, 0.61-2.07; women: 1.19, 0.58-2.43). CONCLUSION: Weight loss among the overweight or obese seemed hazardous to survival. However, weight loss seemed less hazardous to survival among those who remained physically active or those who became active.
Nutr Res Rev. 2009 Jun;22(1):93-108. doi: 10.1017/S0954422409990035. A review and meta-analysis of the effect of weight loss on all-cause mortality risk. Harrington M, Gibson S, Cottrell RC. PMID: 19555520

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Overweight and obesity are associated with increased morbidity and mortality, although the range of body weights that is optimal for health is controversial. It is less clear whether weight loss benefits longevity and hence whether weight reduction is justified as a prime goal for all individuals who are overweight (normally defined as BMI>25 kg/m2). The purpose of the present review was to examine the evidence base for recommending weight loss by diet and lifestyle change as a means of prolonging life. An electronic search identified twenty-six eligible prospective studies that monitored subsequent mortality risk following weight loss by lifestyle change, published up to 2008. Data were extracted and further analysed by meta-analysis, giving particular attention to the influence of confounders. Moderator variables such as reason for weight loss (intentional, unintentional), baseline health status (healthy, unhealthy), baseline BMI (normal, overweight, obese), method used to estimate weight loss (measured weight loss, reported weight loss) and whether models adjusted for physical activity (adjusted data, unadjusted data) were used to classify subgroups for separate analysis. Intentional weight loss per se had a neutral effect on all-cause mortality (relative risk (RR) 1.01; P = 0.89), while weight loss which was unintentional or ill-defined was associated with excess risk of 22 to 39 %. Intentional weight loss had a small benefit for individuals classified as unhealthy (with obesity-related risk factors) (RR 0.87 (95 % CI 0.77, 0.99); P = 0.028), especially unhealthy obese (RR 0.84 (95 % CI 0.73, 0.97); P = 0.018), but appeared to be associated with slightly increased mortality for healthy individuals (RR 1.11 (95 % CI 1.00, 1.22); P = 0.05), and for those who were overweight but not obese (RR 1.09 (95 % CI 1.02, 1.17); P = 0.008). There was no evidence for weight loss conferring either benefit or risk among healthy obese. In conclusion, the available evidence does not support solely advising overweight or obese individuals who are otherwise healthy to lose weight as a means of prolonging life. Other aspects of a healthy lifestyle, especially exercise and dietary quality, should be considered. However, well-designed intervention studies are needed clearly to disentangle the influence of physical activity, diet strategy and body composition, in order to define appropriate advice to those populations that might be expected to benefit.
Int J Cardiol. 2012 Dec 15;162(1):20-6. doi: 10.1016/j.ijcard.2011.09.039. Epub 2011 Oct 29. Inverse relation of body weight and weight change with mortality and morbidity in patients with type 2 diabetes and cardiovascular co-morbidity: An analysis of the PROactive study population. Doehner W, Erdmann E, Cairns R, Clark AL, Dormandy JA, Ferrannini E, Anker SD. PMID: 22037349
CONTEXT: Although weight reduction is a recommended goal in type 2 diabetes mellitus (T2DM), weight loss is linked to impaired survival in patients with some chronic cardiovascular diseases. OBJECTIVE: To assess the association of weight and weight change with mortality and non-fatal cardiovascular outcomes (hospitalisation, myocardial infarction and stroke) in T2DM patients with cardiovascular co-morbidity and the effect of pioglitazone-induced weight change on mortality. SETTING AND PARTICIPANTS: We assessed in a post hoc analysis body weight and weight change in relation to outcome in 5202 patients from the PROactive trial population who had T2DM and evidence of pre-existing cardiovascular disease. Patients were randomized to treatment with pioglitazone or placebo in addition to their concomitant glucose-lowering and cardiovascular medication. Mean follow up was 34.5 months. MAIN OUTCOME MEASURE: The impact of body weight and body weight change on all-cause mortality, cardiovascular mortality, on non-fatal cardiovascular events and on hospitalisation. RESULTS: The lowest mortality was seen in patients with BMI 30-35kg/m(2) at baseline. In comparison to this (reference group), patients in the placebo group with BMI <22kg/m(2) (Hazard Ratio (95% confidence intervals) 2.96 [1.27 to 6.86]; P=0.012) and BMI 22 to 25kg/m(2) (HR 1.88 [1.11 to 3.21]; P=0.019) had a higher all-cause mortality. Weight loss was associated with increased total mortality (HR per 1% body weight: 1.13 [1.11 to 1.16]; P<0.0001), with increased cardiovascular mortality, all-cause hospitalisation and the composite of death, myocardial infarction and stroke.Weight loss of ≥7.5% body weight (seen in 18.3% of patients) was the strongest cut-point to predict impaired survival (multivariable adjusted HR 4.42 [3.30 to 5.94]. Weight gain was not associated with increased mortality. Weight gain in patients treated with pioglitazone (mean+4.0±6.1kg) predicted a better prognosis (HR per 1% weight gain: 0.96 [0.92 to 1.00] P=0.037) compared to patients without weight gain. CONCLUSION: Among patients with T2DM and cardiovascular co-morbidity, overweight and obese patients had a lower mortality compared to patients with normal weight. Weight loss but not weight gain was associated with increased mortality and morbidity. There may be an "obesity paradox" in patients with type 2 diabetes and cardiovascular risk. 
Am J Med. 2011 Oct;124(10):924-30. doi: 10.1016/j.amjmed.2011.04.018. Epub 2011 Jul 26. The obesity paradox and weight loss. Myers J, Lata K, Chowdhury S, McAuley P, Jain N, Froelicher V. PMID: 21798508

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BACKGROUND: An "obesity paradox," in which overweight and obese individuals with established cardiovascular disease have a better prognosis than normal weight subjects, has been reported in a number of clinical cohorts, but little is known about the effects of weight loss on the obesity paradox and its association with health outcomes. METHODS: Weight was determined in 3834 men at the time of a clinically referred exercise test and again during a clinical evaluation a mean of 7 years later. The associations among weight changes, baseline fitness, and other risk markers with cardiovascular and all-cause mortality were determined by Cox proportional hazards analysis. RESULTS: During the follow-up period, 314 subjects died (72 of cardiovascular causes). In a multivariate analysis (including baseline weight, weight change, exercise capacity, and cardiovascular disease), weight gain was associated with lower mortality and weight loss was associated with higher mortality (4% higher per pound lost per year, P<.001) compared with stable weight. For all-cause mortality, the relative risks for the no change, weight gain, and weight loss groups were 1.0 (referent), 0.64 (95% confidence interval, 0.50-0.83), and 1.49 (95% confidence interval, 1.17-1.89), respectively (P<.001). Those who died and exhibited weight loss had a significantly higher prevalence of deaths due to cancer and cardiovascular causes. CONCLUSION: Weight loss was related to higher mortality and weight gain was related to lower mortality when compared with stable weight. The obesity paradox in our sample is explained in part by a combination of non-volitional weight loss related to occult disease and a protective effect of weight gain.
Int J Obes (Lond). 2010 Jun;34(6):1044-50. doi: 10.1038/ijo.2010.41. Epub 2010 Mar 9. Weight loss from maximum body weight and mortality: the Third National Health and Nutrition Examination Survey Linked Mortality File. Ingram DD, Mussolino ME. PMID: 20212495  Source: Office of Analysis and Epidemiology, Centers for Disease Control and Prevention, National Center for Health Statistics, Hyattsville, MD 20782, USA.
OBJECTIVE: The aim of this longitudinal study is to examine the relationship between weight loss from maximum body weight, body mass index (BMI), and mortality in a nationally representative sample of men and women. DESIGN: Longitudinal cohort study. SUBJECTS: In all, 6117 whites, blacks, and Mexican-Americans 50 years and over at baseline who survived at least 3 years of follow-up, from the Third National Health and Nutrition Examination Survey Linked Mortality Files (1988-1994 with passive mortality follow-up through 2000), were included. MEASUREMENTS: Measured body weight and self-reported maximum body weight obtained at baseline. Weight loss (maximum body weight minus baseline weight) was categorized as <5%, 5-<15%, and >or=15%. Maximum BMI (reported maximum weight (kg)/measured baseline height (m)(2)) was categorized as healthy weight (18.5-24.9), overweight (25.0-29.9), and obese (>or=30.0). RESULTS: In all, 1602 deaths were identified. After adjusting for age, race, smoking, health status, and preexisting illness, overweight men with weight loss of 15% or more, overweight women with weight loss of 5-<15%, and women in all BMI categories with weight loss of 15% or more were at increased risk of death from all causes compared with those in the same BMI category who lost <5%; hazard ratios ranged from 1.46 to 2.70. Weight loss of 5-<15% reduced risk of death from cardiovascular diseases among obese men. CONCLUSIONS: Weight loss of 15% or more from maximum body weight is associated with increased risk of death from all causes among overweight men and among women regardless of maximum BMI.
Gend Med. 2009 Dec;6(4):575-86. doi: 10.1016/j.genm.2009.12.003. Weight loss and mortality: a gender-specific analysis of the Tromsø study. Wilsgaard T, Jacobsen BK, Mathiesen EB, Njølstad I. PMID: 20114008

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BACKGROUND: Weight loss has been associated with increased mortality, but findings have been inconsistent. OBJECTIVE: The aim of this study was to examine the association between weight loss and mortality, with a focus on gender differences. METHODS: This was a population-based cohort study in northern Norway of adults, aged 20 to 54 years in 1979, who participated in 2 or 3 consecutive health surveys in 1979-80, 1986-87, and 1994-95. Weight and height were measured at each survey. The Cox proportional hazards regression model was used to estimate hazard ratios for mortality between levels of body mass index (BMI) change during 11 years of follow-up. Participants with prior cardiovascular disease or cancer, or incident cancer within the first 2 years of follow-up, were excluded, as were participants who were pregnant, had missing data, or did not give written consent. RESULTS: A total of 4881 men and 5051 women participated in the present study. The mean age at start of follow-up was 50.8 years (range, 35-70 years) in men and 49.2 years (range, 35-65 years) in women. In men, weight loss was associated with increased all-cause, cardiovascular, and noncardiovascular mortality. The hazard ratio for men for all-cause mortality with a 10-year BMI decrease of 2 kg/m(2) versus a BMI increase of 1 kg/m(2) was 2.09 (95% CI, 1.56-2.81). The association was not significantly modified by initial BMI, age, smoking status, or self-reported attempts of weight loss, or by exclusion of subjects with self-reported poor health, diabetes mellitus, high blood pressure, or high alcohol intake. In women, no association between BMI change and mortality was observed. However, in the subgroup of women who reported no weight-loss attempts, BMI change was significantly associated with mortality risk (P = 0.022). CONCLUSIONS: In this study of a Norwegian population, weight loss was associated with excess mortality in men in all subgroups of weight-loss attempts, daily smoking, and overweight. In women, the only significant effect of BMI change on mortality was observed in those who reported no weight-loss attempts. The observed findings could not be explained by preexisting disease.
Nutr Rev. 2008 Jul;66(7):375-86. doi: 10.1111/j.1753-4887.2008.00047.x.  Intentional weight loss and mortality among initially healthy men and women. Simonsen MK, Hundrup YA, Obel EB, Grønbaek M, Heitmann BL. PMID: 18667013
Most prospective observational studies suggest that weight loss increases the risk of premature death among obese individuals. This is surprising because clinical studies show that weight loss generally leads to overall improvements in cardiovascular risk factors. It is sometimes argued that the increased mortality observed with weight loss must depend on confounding or poor study designs. This review was conducted to summarize results from studies on intentional weight loss and mortality among healthy individuals, while carefully considering the designs and problems in these studies. Evaluation criteria with a rating scale were developed. Of the studies evaluated, two found decreased mortality with intentional weight loss, three found increased mortality, and four found no significant associations between intentional weight loss and total mortality. Thus, it is still not possible for health authorities to make secure recommendations on intentional weight loss. More studies designed to specifically address this issue are warranted.
Eur J Epidemiol. 2007;22(10):665-73. Epub 2007 Aug 4. Weight change, weight cycling and mortality in the ERFORT Male Cohort Study. Rzehak P, Meisinger C, Woelke G, Brasche S, Strube G, Heinrich J. PMID: 17676383
OBJECTIVE: To investigate the effect of weight change and weight fluctuations on all-cause-mortality in men. METHODS: Within a prospective population-based cohort of 1,160 men aged 40-59 years at recruitment, complete weight change patterns from baseline and three follow-up examinations during a period of 15 years of follow-up was used to categorize the 505 men into stable obese, stable non-obese, weight gain, weight loss and weight fluctuation groups. For these men (age range: 55-74 years at start time of survival analysis) further survival was analyzed during the subsequent 15 years. RESULTS: Overall, 183 deaths were observed among the 505 men. Only weight fluctuations had a clear significant impact on all-cause mortality. Adjusted hazard rate ratio (HRR (95%-CI)) was 1.86 (1.31-2.66) after adjustment for age group, pre-existing cardiovascular disease or diabetes mellitus, smoking and socio-economic status. The risk rate due to weight loss was borderline significant (HRR = 1.81 (0.99-3.31)). Risk of death due to weight gain (HRR = 1.15 (0.70-1.88)) or stable obesity (HRR = 1.16 (0.69-1.94)), however, were not significantly increased compared to men staying non-obese for the first 15 years after cohort recruitment. CONCLUSION: Weight fluctuations are a major risk factor for all-cause mortality in middle aged men. Moreover, stable obesity does not increase further mortality in men aged 55-74 years in long-term follow-up.
Negative Psychological Consequences of Dieting

J Am Diet Assoc. 1996 Jun;96(6):589-92; quiz 593-4. Psychological consequences of food restriction. Polivy J.   PMID: 8655907
A review of the literature and research on food restriction indicates that inhibiting food intake has consequences that may not have been anticipated by those attempting such restriction. Starvation and self-imposed dieting appear to result in eating binges once food is available and in psychological manifestations such as preoccupation with food and eating, increased emotional responsiveness and dysphoria, and distractibility. Caution is thus advisable in counseling clients to restrict their eating and diet to lose weight, as the negative sequelae may outweigh the benefits of restraining one's eating. Instead, healthful, balanced eating without specific food restrictions should be recommended as a long-term strategy to avoid the perils of restrictive dieting.
J Am Diet Assoc. 2004;104:1589-1592. Body Image of Chronic Dieters: Lowered Appearance Evaluation and Body Satisfaction. Gingras J, Fitzpatrick J, McCargar L. Full text at: http://www.ryerson.ca/~jgingras/pdf/body_image_chronic_dieters.pdf
This study was conducted to determine the body image of a group of female chronic dieters. Participants were asked to complete a body image questionnaire, and their results were compared with age- and sex-matched reference norms. Chronic dieters possessed significantly lower appearance evaluation, lower body satisfaction, and higher self-classified vs actual body weight compared with reference norms. Body image dissatisfaction may prevent individuals from incorporating beneficial lifestyle behaviors, and thus it is important to address body image dissatisfaction with chronic dieters for the best chance at improving health, regardless of body size.
Health At Every Size® Paradigm

Nutr J. 2011 Jan 24;10:9. Weight science: evaluating the evidence for a paradigm shift. Bacon L, Aphramor L.   PMID: 21261939   Full text at:  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3041737/
Current guidelines recommend that "overweight" and "obese" individuals lose weight through engaging in lifestyle modification involving diet, exercise and other behavior change. This approach reliably induces short term weight loss, but the majority of individuals are unable to maintain weight loss over the long term and do not achieve the putative benefits of improved morbidity and mortality. Concern has arisen that this weight focus is not only ineffective at producing thinner, healthier bodies, but may also have unintended consequences, contributing to food and body preoccupation, repeated cycles of weight loss and regain, distraction from other personal health goals and wider health determinants, reduced self-esteem, eating disorders, other health decrement, and weight stigmatization and discrimination. This concern has drawn increased attention to the ethical implications of recommending treatment that may be ineffective or damaging. A growing trans-disciplinary movement called Health at Every Size (HAES) challenges the value of promoting weight loss and dieting behavior and argues for a shift in focus to weight-neutral outcomes. Randomized controlled clinical trials indicate that a HAES approach is associated with statistically and clinically relevant improvements in physiological measures (e.g., blood pressure, blood lipids), health behaviors (e.g., eating and activity habits, dietary quality), and psychosocial outcomes (such as self-esteem and body image), and that HAES achieves these health outcomes more successfully than weight loss treatment and without the contraindications associated with a weight focus. This paper evaluates the evidence and rationale that justifies shifting the health care paradigm from a conventional weight focus to HAES.
J Am Diet Assoc. 2005 Jun;105(6):929-36. Size acceptance and intuitive eating improve health for obese, female chronic dieters. Bacon L, Stern JS, Van Loan MD, Keim NL.  PMID: 15942543
OBJECTIVE: Examine a model that encourages health at every size as opposed to weight loss. The health at every size concept supports homeostatic regulation and eating intuitively (ie, in response to internal cues of hunger, satiety, and appetite). DESIGN: Six-month, randomized clinical trial; 2-year follow-up. SUBJECTS: White, obese, female chronic dieters, aged 30 to 45 years (N=78). SETTING: Free-living, general community. INTERVENTIONS: Six months of weekly group intervention (health at every size program or diet program), followed by 6 months of monthly aftercare group support. MAIN OUTCOME MEASURES: Anthropometry (weight, body mass index), metabolic fitness (blood pressure, blood lipids), energy expenditure, eating behavior (restraint, eating disorder pathology), and psychology (self-esteem, depression, body image). Attrition, attendance, and participant evaluations of treatment helpfulness were also monitored. STATISTICAL ANALYSIS PERFORMED: Analysis of variance. RESULTS: Cognitive restraint decreased in the health at every size group and increased in the diet group, indicating that both groups implemented their programs. Attrition (6 months) was high in the diet group (41%), compared with 8% in the health at every size group. Fifty percent of both groups returned for 2-year evaluation. Health at every size group members maintained weight, improved in all outcome variables, and sustained improvements. Diet group participants lost weight and showed initial improvement in many variables at 1 year; weight was regained and little improvement was sustained. CONCLUSIONS: The health at every size approach enabled participants to maintain long-term behavior change; the diet approach did not. Encouraging size acceptance, reduction in dieting behavior, and heightened awareness and response to body signals resulted in improved health risk indicators for obese women.
The Benefits of Exercise Without Weight Loss 

Cochrane Database Syst Rev. 2006 Oct 18;(4):CD003817. Exercise for overweight or obesity. Shaw K, Gennat H, O'Rourke P, Del Mar C.  PMID: 17054187
BACKGROUND: Clinical trials have shown that exercise in adults with overweight or obesity can reduce bodyweight. There has been no quantitative systematic review of this in The Cochrane Library. OBJECTIVES: To assess exercise as a means of achieving weight loss in people with overweight or obesity, using randomised controlled clinical trials. SEARCH STRATEGY: Studies were obtained from computerised searches of multiple electronic bibliographic databases. The last search was conducted in January 2006. SELECTION CRITERIA: Studies were included if they were randomised controlled trials that examined body weight change using one or more physical activity intervention in adults with overweight or obesity at baseline and loss to follow-up of participants of less than 15%. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial quality and extracted data. MAIN RESULTS: The 43 studies included 3476 participants. Although significant heterogeneity in some of the main effects' analyses limited ability to pool effect sizes across some studies, a number of pooled effect sizes were calculated. When compared with no treatment, exercise resulted in small weight losses across studies. Exercise combined with diet resulted in a greater weight reduction than diet alone (WMD -1.1 kg; 95% confidence interval (CI) -1.5 to -0.6). Increasing exercise intensity increased the magnitude of weight loss (WMD -1.5 kg; 95% CI -2.3 to -0.7). There were significant differences in other outcome measures such as serum lipids, blood pressure and fasting plasma glucose. Exercise as a sole weight loss intervention resulted in significant reductions in diastolic blood pressure (WMD -2 mmHg; 95% CI -4 to -1), triglycerides (WMD -0.2 mmol/L; 95% CI -0.3 to -0.1) and fasting glucose (WMD -0.2 mmol/L; 95% CI -0.3 to -0.1). Higher intensity exercise resulted in greater reduction in fasting serum glucose than lower intensity exercise (WMD -0.3 mmol/L; 95% CI -0.5 to -0.2). No data were identified on adverse events, quality of life, morbidity, costs or on mortality. AUTHORS' CONCLUSIONS: The results of this review support the use of exercise as a weight loss intervention, particularly when combined with dietary change. Exercise is associated with improved cardiovascular disease risk factors even if no weight is lost.
Diabetes Care. 2004 Jan;27(1):83-8. Exercise capacity and body composition as predictors of mortality among men with diabetes. Church TS, Cheng YJ, Earnest CP, Barlow CE, Gibbons LW, Priest EL, Blair SN.  PMID: 14693971  Abstract: http://care.diabetesjournals.org/content/27/1/83.abstract  Free full text at:   http://care.diabetesjournals.org/content/27/1/83.full.pdf+html
OBJECTIVE—To quantify the relation of fitness to mortality among men with diabetes, adjusted for BMI and within levels of BMI. RESEARCH DESIGN AND METHODS—In this observational cohort study, we calculated all-cause death rates in men with diabetes across quartiles of fitness and BMI categories. Study participants were 2,196 men with diabetes (average age 49.3 years, SD 9.5) who underwent a medical examination, including a maximal exercise test, during 1970 to 1995, with mortality follow-up to 31 December 1996. RESULTS—We identified 275 deaths during 32,161 person-years of observation. Risk of all-cause mortality was inversely related to fitness. For example, in the fully adjusted model, the risk of mortality was 4.5 (2.6–7.6), 2.8 (1.6–4.7), and 1.6 (0.93–2.76) for the first, second, and third fitness quartiles, respectively, with the fourth quartile (highest fitness level) as the referent (P for trend <0.0001). There was no significant trend across BMI categories for mortality after adjustment for fitness. Similar results were found when the fitness-mortality relation was examined within levels of body composition. In normal-weight men with diabetes, the relative risks of mortality were 6.6 (2.8–15.0), 3.2 (1.4–7.0), and 2.2 (1.1–4.6) for the first, second, and third quartiles of fitness, respectively, as compared with the fourth quartile (P for trend <0.0001). We found similar results in the overweight and obese weight categories. CONCLUSIONS—There was a steep inverse gradient between fitness and mortality in this cohort of men with documented diabetes, and this association was independent of BMI.
Diabetes Metab. 2010 Nov;36(5):346-51. Epub 2010 Aug 2. Physical exercise for the prevention and treatment of type 2 diabetes. Sanz C, Gautier JF, Hanaire H.   PMID: 20675173
The prevalence of type 2 diabetes is rapidly increasing worldwide, yet its primary prevention and treatment are still a challenge. The objectives of this review are to assess the effects of exercise on the prevention of type 2 diabetes in high-risk individuals and on glycaemic control in type 2 diabetic patients. Considering the available reports, there is unequivocal and strong evidence that physical exercise can prevent or delay progression to type 2diabetes in subjects with impaired glucose tolerance. Also, lifestyle interventions, including diet and physical exercise, can result in a reduction of around 50% in diabetes incidence that persists even after the individual lifestyle counselling has stopped. In addition, short-term randomized studies have confirmed that physical training based on endurance and/or resistance exercises can also improve blood glucose control in type 2 diabetics with a mean glycated haemoglobin decrease of 0.6%. Thus, physical exercise should be part of any therapeutic strategy to slow the development of type 2 diabetes in high-risk individuals and to improve glucose control in type 2 diabetes.
Curr Opin Lipidol. 2010 Feb;21(1):1-7. Cardiorespiratory fitness and metabolic risk factors in obesity. Hamer M, O'Donovan G.  PMID: 19770655
PURPOSE OF REVIEW: An increase in cardiorespiratory fitness (CRF) through exercise training appears to partly ameliorate the health hazards of obesity and a number of mechanisms might explain the potential benefits. We review recent evidence about the relationships between CRF, exercise training and metabolic risk factors in obesity. RECENT FINDINGS: Epidemiological data have shown that the anti-inflammatory effects of exercise could be an important mechanism in explaining cardio-protective effects of physical activity. Emerging evidence suggests that exercise training reduces markers of inflammation and improves glucose control in obesity, independent of weight loss. Novel mechanisms appear to involve exercise-induced changes in CD14+CD16+ cell populations, expression of toll-like receptors, and key changes in the metabolic regulation of visceral white adipose tissue. Other promising recent research has focused on exercise-induced signalling pathways governing glucose metabolism, such as insulin receptor substrate and Akt substrate. Using novel imaging techniques, studies have demonstrated exercise-induced improvements in lipoprotein subfraction particle size, and reduction in visceral adipose tissue and liver fat, independent of weight loss. These effects appear to be mostly restricted to interventions consisting of relatively high doses of exercise or exercise combined with calorie restriction, although further work is required to elucidate the dose-response relationships. SUMMARY: Physical activity and the pursuit of physical fitness are important in the treatment of obesity because exercise training can improve a number of metabolic risk factors independent of weight loss. Thus exercise can provide important health benefits irrespective of weight loss in obese and overweight individuals.
J Appl Physiol. 2005 Sep;99(3):1220-5. Epub 2005 Apr 28. Exercise without weight loss is an effective strategy for obesity reduction in obese individuals with and without Type 2 diabetes. Lee S, Kuk JL, Davidson LE, Hudson R, Kilpatrick K, Graham TE, Ross R.   PMID: 15860689  Free full text at:  http://jap.physiology.org/content/99/3/1220.abstract
It is unclear whether chronic exercise without caloric restriction or weight loss is a useful strategy for obesity reduction in obese men with and without Type 2 diabetes (T2D). We examined the effects of exercise without weight loss on total and regional adiposity and skeletal muscle mass and composition in lean men and in obese men with and without T2D. Twenty-four men participated in 13 wk of supervised aerobic exercise, five times per week for 60 min at a moderate intensity (approximately 60% peak oxygen uptake). Total and regional body composition was measured by magnetic resonance imaging. Skeletal muscle composition was determined using computed tomography. Cardiorespiratory fitness was assessed using a graded maximal treadmill test. Body weight did not change within any group in response to exercise (P > 0.1). Significant reductions in total, abdominal subcutaneous, and visceral fat were observed within each group (P < 0.01). The reduction in total and abdominal subcutaneous fat was not different (P > 0.1) between groups; however, the reduction in visceral fat was greater (P < 0.01) in the obese and T2D groups by comparison to the lean group. A significant (P < 0.01) increase in total skeletal muscle, high-density muscle area, and mean muscle attenuation was observed independent of group, and these changes were not different between groups (P > 0.1). Accordingly, whole body fat-to-muscle ratio was increased (P < 0.01) independent of groups. In conclusion, regular exercise without weight loss is associated with a substantial reduction in total and visceral fat and in skeletal muscle lipid in both obesity and T2D.
Diabetes Care. 2012 Jun;35(6):1347-54. doi: 10.2337/dc11-1859. Epub 2012 Mar 7. Changes in physical fitness predict improvements in modifiable cardiovascular risk factors independently of bodyweight loss in subjects with type 2 diabetes participating in the Italian Diabetes and Exercise Study (IDES). Balducci S, Zanuso S, Cardelli P, Salvi L, Mazzitelli G, Bazuro A, Iacobini C, Nicolucci A, Pugliese G; Italian Diabetes Exercise Study (IDES) Investigators. PMID: 22399699
...RESEARCH DESIGN AND METHODS: Sedentary patients with type 2 diabetes (n = 606) were enrolled in 22 outpatient diabetes clinics and randomized to twice-a-week supervised aerobic and resistance training plus exercise counseling versus counseling alone for 12 months. Baseline to end-of-study changes in cardiorespiratory fitness, strength, and flexibility, as assessed by Vo(2max) estimation, a 5-8 maximal repetition test, and a hip/trunk flexibility test, respectively, were calculated in the whole cohort, and multiple regression analyses were applied to assess the relationship with cardiovascular risk factors. RESULTS: Changes in Vo(2max), upper and lower body strength, and flexibility were significantly associated with the variation in the volume of physical activity, HbA(1c), BMI, waist circumference, high-sensitivity C-reactive protein (hs-CRP), coronary heart disease (CHD) risk score, and inversely, HDL cholesterol. Changes in fitness predicted improvements in HbA(1c), waist circumference, HDL cholesterol, hs-CRP, and CHD risk score, independent of study arm, BMI, and in case of strength, also waist circumference. CONCLUSIONS: Physical activity/exercise-induced increases in fitness, particularly muscular, predict improvements in cardiovascular risk factors in subjects with type 2 diabetes independently of weight loss, thus indicating the need for targeting fitness in these individuals, particularly in subjects who struggle to lose weight.
Circulation. 2011 Dec 6;124(23):2483-90. doi: 10.1161/CIRCULATIONAHA.111.038422.  Long-term effects of changes in cardiorespiratory fitness and body mass index on all-cause and cardiovasculardisease mortality in men: the Aerobics Center Longitudinal Study. Lee DC, Sui X, Artero EG, Lee IM, Church TS, McAuley PA, Stanford FC, Kohl HW 3rd, Blair SN. PMID: 22144631

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...METHODS AND RESULTS: We examined the independent and combined associations of changes in fitness and BMI with all-cause and cardiovascular disease (CVD) mortality in 14 345 men (mean age 44 years) with at least 2 medical examinations. Fitness, in metabolic equivalents (METs), was estimated from a maximal treadmill test. BMI was calculated using measured weight and height. Changes in fitness and BMI between the baseline and last examinations over 6.3 years were classified into loss, stable, or gain groups. During 11.4 years of follow-up after the last examination, 914 all-cause and 300 CVD deaths occurred. The hazard ratios (95% confidence intervals) of all-cause and CVD mortality were 0.70 (0.59-0.83) and 0.73 (0.54-0.98) for stable fitness, and 0.61 (0.51-0.73) and 0.58 (0.42-0.80) for fitness gain, respectively, compared with fitness loss in multivariable analyses including BMI change. Every 1-MET improvement was associated with 15% and 19% lower risk of all-cause and CVD mortality, respectively. BMI change was not associated with all-cause or CVD mortality after adjusting for possible confounders and fitness change. In the combined analyses, men who lost fitness had higher all-cause and CVD mortality risks regardless of BMI change. CONCLUSIONS: Maintaining or improving fitness is associated with a lower risk of all-cause and CVD mortality in men. Preventing age-associated fitness loss is important for longevity regardless of BMI change.

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