2-year Weight Change Research Articles

Weight Change, Initial BMI, and Mortality Among Middle- and Older-aged Adults

It is not known how the relationship between weight change and mortality is influenced by initial body mass index (BMI) or the magnitude of weight change. We use the nationally representative Health and Retirement Study (n = 13,104; follow-up 1992-2006) and Cox regression analysis to estimate relative mortality risks for 2-year weight change by initial BMI among 50- to-70-year-old Americans. We defined small weight loss or gain as a change of 1-2.9 BMI units and large weight loss or gain as a change of 3-5 BMI units. Large and small weight losses were associated with excess mortality for all initial BMI levels below 32 kg/m (eg, hazard ratio [HR] for large weight loss from BMI of 30 = 1.61 [95% confidence interval = 1.31-1.98]; HR for small weight loss from BMI of 30 = 1.19 [1.06-1.28]). Large weight gains were associated with excess mortality only at high BMIs (eg, HR for large weight gain from BMI of 35 = 1.33 [1.00-1.77]). Small weight gains were not associated with excess mortality for any initial BMI level. The weight loss-mortality association was robust to adjustments for health status and to sensitivity analyses considering unobserved confounders. Weight loss is associated with excess mortality among normal, overweight, and mildly obese middle- and older-aged adults. The excess risk increases for larger losses and lower initial BMI. These results suggest that the potential benefits of a lower BMI may be offset by the negative effects associated with weight loss. Weight gain may be associated with excess mortality only among obese people with an initial BMI over 35.

Three-Year Measured Weight Change in the African American Health Study

This study examines 3-year weight change in African Americans. Nine hundred and ninety-eight participants 49 to 65 years old were assessed at baseline and 3 years later. Weight was measured, and weight change was defined as clinically meaningful increases or decreases (+/- 5 kg). Potential risk factors were investigated using multinomial logistic regression. In-home measured weights were available for 752 participants (75%): 504 (67%) had stable weights, 131 (17%) gained more than 5 kg, and 117 (16%) lost more than 5 kg. Among all participants, the risks for weight gains were cancer, chronic obstructive pulmonary disease, lower income, and Medicaid status; the risks for weight losses were angina, cancer, high measured systolic blood pressure, asthma, and physical inactivity. Sex-stratified analyses reveal differences involving age, socioeconomic status, cancer, blood pressure, and lower body function. Three-year weight changes in middle-aged African Americans were frequent and significantly associated with several risk factors.

Fat Intake and Weight Development from 9 to 16 Years of Age: The European Youth Heart Study – a Longitudinal Study

Objective: The literature on associations between fat intake and weight development among both children and adults is inconsistent, even if it is generally assumed that a high dietary fat intake is a major determinant of obesity. The present study aimed at investigating the association between fat intake and weight development among a cohort of children aged 9–10 years at baseline and 15–16 years at follow-up, and, further, at investigating whether parents’ obesity is modifying the association. Method: Among 384 subjects aged 9 years, data on dietary intake, BMI z-score, physical activity, inactivity, parents’ social status, parents’ body mass index, child birth weight, and status of puberty was obtained in 1997. Weight and height was measured both at baseline and at 6-year follow-up, and BMI z-score was calculated. Linear regression was used to assess the role of fat intake on subsequent weight change between 1997 and 2003 with the above-mentioned variables as confounders, in 3 different models and for each sex separately. Results: The analysis showed no relation between fat intake (both absolute intake and fat energy percent) at 9 years and subsequent 6-year weight change. Only BMI z-score at baseline had a significant relation to weight change for both sexes, and number of obese parents had significant relation to weight change in girls. Number of overweight parents did not modify the association between fat intake and weight change. Conclusion: This study was unable to find a relation between fat intake and 6-year weight change among 9-year-old children. No interaction was seen between number of overweight parents on the relation between fat intake and subsequent weight change.

Weight change and quality of life in a community-based population

Abstract *Objectives:* This study investigates the longitudinal association between 5-year weight change and quality of life (QoL) in Dutch men and women.*Design:* A prospective cohort study (1998, 2000, 2003) in a population based sample. Subjects: 2,414 men and women from the Maastricht region of the Netherlands.*Measurements:* QoL outcomes were measured by the RAND-36 (eight subscales and two overall composite scores, physical and mental health (PCS and MCS)). Weight was measured on a scale. Weight change was calculated as change in weight between 1998 and 2003. In addition, 5-year weight change was also categorized in three groups: weight losers, weight maintainers, and weight gainers. All analyses were stratified for gender. *Results:* A total of 598 men (50%) and 646 women (54%) maintained their weight, 177 men (15%) and 163 women (14%) lost more than 2.5 kg, and 410 men (35%) and 379 women (32%) gained more than 2.5 kg. Associations between 5-year weight change and QoL were found for MCS ([beta] = 0.13, 95% CI: 0.02∣0.24) in women, and PCS ([beta] = -0.09, 95% CI: -0.17∣-0.00; [beta] = -0.10, 95% CI: -0.19∣-0.01) in men and women respectively. Moreover, associations between weight change and QoL were most pronounced for women of normal weight and obese men. Furthermore, in both genders, weight gainers showed a greater reduction on all physical components of QoL compared with weight maintainers. However, after 5-years weight gainers and weight losers did not significantly differ from weight maintainers in the mean change of MCS and PCS.*Conclusion:* Weight gain was inversely associated with the physical domains of QoL in women and obese men. Conversely, in women, weight gain was positively associated with the mental domains of QoL. No differences between weight losers and weight gainers were found in mean change of QoL compared with weight maintainers.

Effect of 3‐Year Weight History on Blood Pressure: The Atherosclerosis Risk in Communities Study

The objective of this study was to examine the effect of weight history on blood pressure. Extant data from the Atherosclerosis Risk in Communities (ARIC) study were used to compare blood pressure in women (n=5,675) and men (n=4,893) with different 3-year weight histories, but similar current BMI. We used mixed models regression adjusted for ethnicity, age, education, field center, smoking, alcohol consumption, antihypertensive medications, interval length, and BMI at follow-up. We also examined associations between 3-year weight history and blood pressure within weight status categories (normal weight (>or=18.5 to <25.0 kg/m2), overweight (>or=25.0 to <30.0 kg/m2), and obese (>or=30.0 kg/m2)). We found weight history affected both systolic and diastolic blood pressures. Compared to men at the same BMI who had maintained their weight, men who had experienced a 10% weight gain over the previous 3 years had systolic and diastolic blood pressures that were 2.6 and 1.9 mm Hg higher, respectively (P<0.001 for both). Associations in women were in the same direction, but smaller at 0.9 and 0.6 mm Hg (P<0.001). With the exception of diastolic blood pressure in normal weight women, we found no significant interactions between weight change and current weight status. In conclusion, some of the variation in blood pressure among individuals at the same BMI may be due to weight change history. Effects of 3-year weight change history appear to be stronger and more consistent in men than in women, and generally similar regardless of current weight status.

Breakfast Eating and Weight Change in a 5-Year Prospective Analysis of Adolescents: Project EAT (Eating Among Teens)

Breakfast-eating frequency declines through adolescence and has been inversely associated with body weight in cross-sectional studies, with few prospective studies on this topic. This study was conducted to examine the association between breakfast frequency and 5-year body weight change in 2216 adolescents. Project EAT (Eating Among Teens) was a 5-year longitudinal study of eating patterns and weight concerns among adolescents. Surveys were completed in 1998-1999 (time 1) and 2003-2004 (time 2). Multivariable linear regression was used to examine the association between breakfast frequency and change in BMI, with adjustment for age, socioeconomic status, race, physical activity, time 1 BMI and breakfast category, and time 1 dietary and weight-related variables. At time 1, frequency of breakfast was directly associated with intake of carbohydrate and fiber, socioeconomic status, white race, and physical activity and inversely associated with smoking and alcohol consumption and dieting and weight-control behaviors. In cross-sectional analyses at times 1 and 2, inverse associations between breakfast frequency and BMI remained largely independent of all of the confounding and dietary factors. Weight-related factors (concerns, behaviors, and pressures) explained little of the breakfast-BMI association. In prospective analyses, frequency of breakfast was inversely associated with BMI in a dose-response manner. Further adjustment for confounding and dietary factors did not seem to explain the association, but adjustment for weight-related variables seemed to partly explain this finding. Although experimental studies are needed to verify whether the association between breakfast and body weight is of a causal nature, our findings support the importance of promoting regular breakfast consumption among adolescents. Future studies should further examine the role of breakfast habits among youth who are particularly concerned about their weight.

The Pro12Ala variant at the peroxisome proliferator-activated receptor γ gene and change in obesity-related traits in the Diabetes Prevention Program

Peroxisome proliferator-activated receptor gamma (PPARgamma), encoded by the PPARG gene, regulates insulin sensitivity and adipogenesis, and may bind polyunsaturated fatty acids (PUFA) and thiazolidinediones in a ligand-dependent manner. The PPARG proline for alanine substitution at position 12 (Pro12Ala polymorphism) has been related with obesity directly and via interaction with PUFA. We tested the effect-modifying role of Pro12Ala on the 1 year change in obesity-related traits in a randomised clinical trial of treatment with metformin (n = 989), troglitazone (n = 363) or lifestyle modification (n = 1,004) vs placebo (n = 1,000) for diabetes prevention in high-risk individuals. At baseline, Ala12 carriers had larger waists (p < 0.001) and, in a subset, more subcutaneous adipose tissue (SAT; lumbar 2/3; p = 0.04) than Pro12 homozygotes. There was a genotype-by-intervention interaction on 1-year weight change (p = 0.01); in the placebo arm, Pro12 homozygotes gained weight and Ala12 carriers lost weight (p = 0.001). In the metformin and lifestyle arms, weight loss occurred across genotypes, but was greatest in Ala12 carriers (p < 0.05). Troglitazone treatment induced weight gain, which tended to be greater in Ala12 carriers (p = 0.08). In the placebo group, SAT (lumbar 2/3, lumbar 4/5) decreased in Ala12 allele carriers, but was unchanged in Pro12 homozygotes (p < or = 0.005). With metformin treatment, SAT decreased independently of genotype. In the lifestyle arm, SAT (lumbar 2/3) reductions occurred across genotypes, but were greater in Ala12 carriers (p = 0.03). A genotype-by-PUFA intake interaction on reduction in visceral fat (lumbar 4/5; p = 0.04) was also observed, which was most evident with metformin treatment (p < 0.001). Within the Diabetes Prevention Program, the Ala12 allele influences central obesity, an effect which may differ by treatment group and dietary PUFA intake (ClinicalTrials.gov ID no: NCT00004992).

Preventing weight gain: a population cohort study of the nature and effectiveness of mid-age women's weight control practices

To examine women's weight control practices and their effectiveness in preventing weight gain. Retrospective cohort study of weight control practices and 2-year weight change among mid-age women participating in the Australian Longitudinal Study on Women's Health (ALSWH). 11,589 Australian women (aged 47-52 years). The prevalence and types of self-reported weight control practices used were assessed by a nine-item instrument. Two-year weight change was self-reported and adjusted for baseline body mass index (BMI) and other potential confounders. Seventy-four per cent of the cohort (N=8556) reported actively trying to control their weight. Dietary modification was used more frequently than exercise. Two-thirds of the weight-controlling women used a combination of practices, the two most common being 'decreased food quantity, cut down on fats/sugars and exercise' (32%, baseline BMI 25.87(0.10)), and 'decreased food quantity and cut down on fats/sugars without exercise' (15.6%, baseline BMI 27.04(0.14)). Potentially health-damaging practices (smoking, laxatives, fasting) were relatively uncommon, at 7.9%. Only one combination of practices (decreased food quantity, cut down on fats/sugars, use of a commercial weight loss programme and exercise) prevented mean weight gain (-0.03 kg), whereas the mean (s.d.) weight of the cohort increased (+1.19(4.78)) over the 2-year period. The majority of mid-age women attempting weight control used practices consistent with public health messages. Despite their efforts, the group was mostly unsuccessful in preventing weight gain. Public health authorities and health practitioners may need to make more quantitative recommendations and emphasize the importance of balancing physical activity with dietary intake to achieve successful weight control for women at this life stage.

Calcium Intake and 10-Year Weight Change in Middle-Aged Adults

Objective The goal of this study was to examine the purported effects of calcium on modulating body weight. Design Retrospective data was used to assess the relationship between calcium intake and weight change over an 8- to 12-year period among middle-aged adults. Subjects Participants were 10,591 men and women aged 53 to 57 years recruited during 2000-2002. Statistical Analysis Linear regression was used to model associations of 10-year weight change and calcium intake, adjusted for weight at age 45 years, energy intake, physical activity, and other factors. Results Calcium intake was associated with 10-year weight change only in women. Women with current calcium supplement dose of >500 mg/day had a 10-year weight gain of 5.1 kg (95% confidence interval 4.7 to 5.5) compared to 6.9 kg (95% confidence interval 6.5 to 7.4) among nonusers ( P for trend=0.001). Trends were similar for total calcium intake from diet plus supplements ( P for trend=0.001). Dietary calcium alone had no significant effect on 10-year weight change. Conclusions Increasing total calcium intake, in the form of calcium supplementation, may be beneficial to weight maintenance, especially in women during midlife.

Weight change and mortality among older Mexican Americans

Weight changes are predictors of health outcomes in older people. The purpose of this study is to examine the association between 2-year weight change and mortality in older Mexican Americans. Seven year prospective cohort study of 1,749 non-institutionalized Mexican American men and women aged 65 and older residing in five Southwestern states. Measures include self-reports of medical conditions (heart attack, stroke, diabetes, hypertension, hip fracture or cancer), functional disability, high depressive symptoms, smoking status, a summary performance score of lower body function, hand grip muscle strength, and body mass index (BMI). Weight change was examined by comparing the baseline weight to the weight two years later to estimate the hazard of death within the following five-year period. Of the 1,749 subjects, 396 (22.6%) lost 5% or more weight, 984 (56.3%) had weight that remained stable, and 369 (21.1%) gained 5% or more weight between baseline and the 2-year follow-up period. Of the ones who lost 5% of weight, 28% died as compared to 19.7% and 15.2% of those whose weight remained stable and those who gained weight after 5 years, respectively. The hazard ratio (HR) of death for the group that lost 5% or more of their weight compared to the reference group (stable weight) was 1.35 (95% CI 1.06-1.70) after controlling for demographic variables, BMI, and waist circumference at baseline and 1.32 (95% CI 1.04-1.67) after controlling for all covariates. The HR of death for the group that gained 5% or more of weight was 0.78 (95% CI 0.58-1.05) after controlling for demographic variables, BMI, and waist circumference at baseline and 0.77 (95% CI 0.57-1.04) after controlling for all covariates. Weight loss is an independent predictor of mortality among older Mexican Americans, after controlling for relevant risk factors.

An investigation of psychological, social and environmental correlates of obesity and weight gain in young women

This study explored the biological, psychological, social and environmental correlates of young women's current weight and retrospective 2-year weight change. A total of 790 young women (mean age 26.8 years), sampled from the Australian Longitudinal Study on Women's Health, provided self-reported data on their height and weight, sociodemographics and a range of biological, psychological, social and environmental variables. Several variables from all domains (biological, psychological, social support and environmental) were correlated with higher body mass index, and less strongly greater 2-year weight change. Key correlates included the tendency to never put on weight, no matter what; self-efficacy for avoiding weight gain, and for healthy eating; attention paid to weight; family support and friends' support/sabotage of physical activity/healthy eating; and perceived difficulty of taking the stairs rather than the elevator as part of the daily routine. Intervention strategies aimed at reducing weight gain and obesity may need to focus on social and environmental, as well as psychological factors; however, further research is necessary to confirm these findings given that a number of hypothesized associations were not observed.

Weight change and lower body disability in older Mexican Americans.

To examine the association between 2-year weight change and onset of lower body disability over time in older Mexican Americans. Data were from the Hispanic Established Population for the Epidemiological Study of the Elderly (1993-2001). Weight change was examined by comparing baseline weight to weight at 2-year follow-up. Incidence of lower body disability was studied from the end of this period through an additional 5 years. Five southwestern states: Texas, New Mexico, Colorado, Arizona, and California. One thousand seven hundred thirty-seven noninstitutionalized Mexican-American men and women aged 65 and older who reported no limitation in activities of daily living (ADLs) and were able to perform the walk test at 2-year follow-up. In-home interviews assessed sociodemographic factors, self-reported physician diagnoses of medical conditions (arthritis, diabetes mellitus, heart attack, stroke, hip fracture, and cancer), self-reported ADLs, depressive symptoms, and number of hospitalizations. Cognitive function, handgrip muscle strength, and body mass index (BMI) were obtained. The outcomes were any limitation of lower body ADL (walking across a small room, bathing, transferring from a bed to a chair, and using the toilet) and limitation on the walk test over subsequent 5-year follow-up period. General Estimation Equation (GEE) was used to estimate lower body disability over time. Weight change of 5% or more occurred in 42.3% of the participants; 21.7% lost weight, 20.6% gained weight, and 57.7% had stable weight. Using GEE analysis, with stable weight as the reference, weight loss of 5% or more was associated with greater risk of any lower body ADL limitation (odds ratio (OR)=1.43, 95% confidence interval (CI)=1.06-1.95) and walking limitation (OR=1.35, 95% CI=1.03-1.76) after controlling for sociodemographic variables and BMI at baseline. Weight gain of 5% or more was associated with greater risk of any lower body ADL limitation (OR=1.39, 95% CI=1.02-1.89), after controlling for sociodemographic variables and BMI at baseline. When medical conditions, handgrip muscle strength, high depressive symptomatology, cognitive function, and hospitalization were added to the equation, the relationship between 2-year weight change (>5% loss or >5% gain) and lower body disability decreased. Health conditions and muscle strength partially mediate the association between weight loss or gain and future loss of ability to walk and independently perform ADLs.

Estimated change in physical activity level (PAL) and prediction of 5-year weight change in men: the Aerobics Center Longitudinal Study

To determine the relation between the average daily physical activity level (PAL) and the trajectory of weight change in men at risk for weight gain. Clinic-based cohort study over an average of 5 y. Healthy men (N=2501) ages 20-55 y participating in the Aerobics Center Longitudinal Study who had received at least four medical examinations at the Cooper Clinic between 1970 and 1998. Daily leisure-time physical activity was reported and body weight was measured at all four examinations. The average daily PAL (METs 24 h(-1)) was estimated from all activities, as well as from other incidental active and passive activities. Weight change over four examinations was regressed on the change in PAL between the first and third examinations. Random coefficient regression modeling indicated a curvilinear slope for weight gain over the follow-up among those maintaining the same PAL between the first and third examinations. Weight gain was further accelerated among men who decreased their activity. A shift from a low PAL (<1.45 METs 24 h(-1)) to a moderate (1.45-1.60 METs 24 h(-1)) or high (>1.60 METs 24 h(-1)) PAL was necessary for weight loss over time. Men with initially the lowest PAL had the greatest benefit from increasing activity. Daily PAL was inversely related to weight gain in this cohort. Increasing to or maintaining a daily PAL at least 60% above the resting metabolic rate (ie, PAL >1.60 METs 24 h(-1)) may be necessary to maintain body weight in middle-age and can be achieved by incorporating 45-60 min of brisk walking, gardening/yardwork, or cycling into the daily routine.

Glycemic Index and Dietary Fiber and the Risk of Type 2 Diabetes

To examine associations between type 2 diabetes and fiber, glycemic load (GL), dietary glycemic index (GI), and fiber-rich foods. This was a prospective study of 36,787 men and women aged 40-69 years without diabetes. For all self-reported cases of diabetes at 4-year follow-up, confirmation of diagnosis was sought from medical practitioners. Case subjects were those who reported diabetes at follow-up and for whom there was no evidence that they did not have type 2 diabetes. Data were analyzed with logistic regression, adjusting for country of birth, physical activity, family history of diabetes, alcohol and energy intake, education, 5-year weight change, sex, and age. Follow-up was completed by 31,641 (86%) participants, and 365 cases were identified. The odds ratio (OR) for the highest quartile of white bread intake compared with the lowest was 1.37 (95% CI 1.04-1.81; P for trend = 0.001). Intakes of carbohydrate (OR per 200 g/day 0.58, 0.36-0.95), sugars (OR per 100 g/day 0.61, 0.47-0.79), and magnesium (OR per 500 mg/day 0.62, 0.43-0.90) were inversely associated with incidence of diabetes, whereas intake of starch (OR per 100 g/day 1.47, 1.06-2.05) and dietary GI (OR per 10 units 1.32, 1.05-1.66) were positively associated with diabetes. These relationships were attenuated after adjustment for BMI and waist-to-hip ratio. Reducing dietary GI while maintaining a high carbohydrate intake may reduce the risk of type 2 diabetes. One way to achieve this would be to substitute white bread with low-GI breads.

Occupational factors and 5-year weight change among men in a danish national cohort.

This study explored whether factors related to the work environment could predict changes in body mass index (BMI) and whether the effect of psychosocial factors was dependent on baseline BMI. The sample consisted of 1,980 male employees from the Danish National Work Environment Cohort Study. Changes in BMI between 1995 and 2000 were analyzed, by multiple regression, as a function of background variables and a series of occupational variables obtained in 1995. Age, baseline BMI, job insecurity, and psychological demands predicted changes in BMI. Job insecurity and high or low psychological demands increased the likelihood of weight gain among obese employees, whereas they increased the likelihood of weight loss among employees with a low BMI.

Patterns and demographic predictors of 5-year weight change in a multi-ethnic cohort of men and women in Australia.

This study investigated 5-year trends in body weight, overweight and obesity and their association with sociodemographic variables in a large, multi-ethnic community sample of Australian adults. This prospective population study used baseline and 5-year follow-up data from participants in the Melbourne Collaborative Cohort Study (MCCS). Population study in Melbourne, Australia. In total, 12 125 men and 17 674 women aged 35-69 years at baseline. Mean 5-year weight change in this sample was +1.58 (standard deviation (SD) 4.82) kg for men and +2.42 (SD 5.17) kg for women. Younger (35-44 years) men and, in particular, women gained more weight than older adults and were at highest risk of major weight gain (> or =5 kg) and becoming overweight. Risk of major weight gain and associations between demographic variables and weight change did not vary greatly by ethnicity. Education level showed complex associations with weight outcomes that differed by sex and ethnicity. Multivariate analyses showed that, among men, higher initial body weight was associated with decreased likelihood of major weight gain, whereas among women, those initially overweight or obese were about 20% more likely to experience major weight gain than underweight or healthy weight women. Findings of widespread weight gain across this entire population sample, and particularly among younger women and women who were already overweight, are a cause for alarm. The prevention of weight gain and obesity across the entire population should be an urgent public health priority. Young-to-mid adulthood appears to be a critical time to intervene to prevent future weight gain.

Plasma C-reactive protein concentrations in relation to 5-year body weight change among children: the Taipei Children Heart Study.

C-reactive protein (CRP), a nonspecific inflammatory marker, may be associated with the development of cardiovascular disease (CVD) among adults. The purpose of this study is to evaluate the relation between plasma CRP levels and 5-y body weight and body mass index (BMI) change among school children in Taiwan. In 1995, we conducted an epidemiological survey to evaluate the anthropometric characteristics and CVD risk factors among 1500, aged 12-15 y, school children in Taipei. We measured plasma high sensitivity CRP levels using nephelometric method. In 2000, we followed these children to evaluate their changes in body height, weight and BMI during 5 y. In general, boys were taller, heavier and had higher BMI than girls at the baseline (1995) and at the 5-y follow-up (2000). Baseline plasma CRP levels were positively correlated with body weight and BMI in both 1995 and 2000. However, plasma CRP levels were negatively correlated with 5-y BMI change in both genders. We further divided the children into three subgroups based on their baseline CRP levels (nondetected, 0.188-1.00 and >1.0 mg/dl). Children in the higher plasma CRP levels (>1.0 mg/dl) were heavier and had higher BMI (both in 1995 and 2000) than those children with nondetected CRP levels. However, children with higher CRP subgroup had a lower 5-y increasing of BMI and there was even a decrease of BMI levels among the higher CRP girls. From this prospective study, we found that baseline plasma CRP levels were positively correlated with the baseline and the 5-y follow-up body weight and BMI in both genders. However, plasma CRP levels may not be a good predictor of 5-y body weight and BMI changes among children in Taiwan.

Metabolic predictors of 5-year change in weight and waist circumference in a triethnic population: the insulin resistance atherosclerosis study.

Insulin resistance, insulin secretion, and glucose tolerance may predict weight change. A total of 1,194 adults aged 39-69 years at baseline (46% with normal glucose tolerance according to World Health Organization criteria, 23% with impaired glucose tolerance, and 31% with type 2 diabetes mellitus who were not taking insulin) were evaluated at baseline (1992-1994) and after 5 years. Baseline insulin sensitivity (S(I)) was measured by means of a 12-sample, insulin-enhanced, frequently sampled intravenous glucose tolerance test. Insulin secretion was assessed in terms of acute insulin response and disposition index, both obtained from the frequently sampled intravenous glucose tolerance test. At follow-up, 25% of subjects had lost more than 2.27 kg (>5 pounds), 38% weighed within 2.27 kg of their baseline weight, and 37% had gained more than 2.27 kg. In separate models, greater weight loss occurred among those with type 2 diabetes than among those with either impaired glucose tolerance or normal glucose tolerance (p < 0.001); baseline acute insulin response and disposition index were positively associated and baseline fasting insulin level was inversely associated with 5-year weight change (p < 0.05 for each; data were adjusted for baseline body mass index and demographic and behavior change variables). Upon simultaneous inclusion of metabolic variables within glucose tolerance status groups, none was a significant predictor of weight loss. Apart from glucose tolerance status itself, measures of insulin metabolism appear to have little effect on weight change over 5 years.

Associations of leptin, insulin resistance and thyroid function with long-term weight loss in dieting obese men.

The aim of the present study was to identify predictors of weight loss in obese men participating in a 2-year behaviour modification programme. Longitudinal, clinical intervention study of a behaviour modifying weight loss program. University Hospital, Stockholm, Sweden. Forty-four obese men (age, 42.7 +/- 1.1 years: BMI, 37.1 +/- 0.6 kg m(-2), mean +/- SEM) followed for 2 years. Behaviour modification weight loss programme. Associations between plasma leptin and thyroid function tests, insulin resistance by homeostatic model assessment (HOMA), dietary recall and anthropometrically determined body composition. At baseline, there were significant correlations between plasma leptin and body mass index (BMI), fat-free mass (FFM) and insulin resistance. Median weight loss over 2 years was 4.9 kg (range, -27.2 to +11.9). Baseline serum leptin concentrations adjusted for BMI (leptin/BMI ratio) were significantly correlated with 2-year weight change (r = 0.34, P = 0.04). A subset of seven of the 44 men gained weight over the 2 years. These 'gainers' differed significantly in initial leptin/BMI ratio (0.62 +/- 0.07) compared with the 37 'losers' (0.42 +/- 0.03, P < 0.05). In a multiple regression model, baseline leptin, insulin and age predicted 22% of the variance in weight change with no additional significant contribution from BMI, FFM, waist:hip ratio, thyroid function tests or energy intake. There was a strong correlation between the change in leptin concentrations and the change in insulin resistance from baseline to 2-year follow-up (r = 0.54; P < 0.001). Baseline plasma leptin concentrations predicted long-term weight loss. Inappropriate leptin secretion or disposal, corrected for BMI, was associated with failure to maintain weight loss in obese men in a behaviour modification weight loss programme.

Predictors of weight change in middle-aged and old men.

Studies on weight change and mortality have yielded inconclusive results. This 10-year prospective study was undertaken to improve understanding of factors affecting weight change. The subjects were 1,143 men, aged 36 to 88 years (mean, 53.3 years) at entry. A questionnaire was filled in at entry and at the end of the follow-up with queries on weight, height, weight at the age of 20, physician-diagnosed diseases, smoking, alcohol use, dietary habits, leisure physical activity, occupation, present occupational activity, living conditions (living alone or cohabiting), and former athletic status. Further information on morbidity was obtained from selected national registers. Factors predicting weight change during the study were identified by stepwise linear multiple regression analysis. The mean 10-year weight change was 0.8 (range, -29 to +24) kg. Age at entry (beta-coefficient, -0.17, SE 0.02), weight at entry (beta, -0.03, SE 0.01), diabetes at entry (beta, -3.55, SE 1.02), diabetes diagnosed after entry (beta, -3.94, SE 0.96), malignant cancer (beta, -1.60, SE 0.70), being a smoker (beta, - 1.59, SE 0.48), and increased physical activity (beta, - 1.27, SE 0.54) were significantly (p < 0.05) associated with weight loss in the final model. The model explained 13% of the variance of weight change. The results emphasize the complexity of weight change. Some factors associated with weight change are apparently negatively, and some positively, associated with health. This could explain the equivocal findings on weight change and mortality in the literature.