Long-term Changes In Body Weight Research Articles

Effects of behavioral treatment on long‐term weight loss: Lessons learned from the look AHEAD trial

The eight-year weight loss findings from the Look AHEAD Study (1) reported in this issue of Obesity have important implications for treatment of overweight and obesity. As the largest and longest randomized controlled trial of a behavioral intervention for weight loss, the results from Look AHEAD provide vital information about the short- and long-term effects of an intensive lifestyle intervention for weight management. Over the course of eight years, participants in Look AHEAD’s intensive lifestyle intervention achieved significantly larger mean reductions in body weight than those randomized to a diabetes support and education group. Moreover, at year 8, significantly greater percentages of lifestyle intervention participants attained weight reductions of 5% or greater and 10% or greater compared with those in the diabetes support and education condition. The ramifications of these findings with respect to lifestyle treatment of obesity are indeed notable. The Look AHEAD results demonstrate that weight losses can be achieved and, for the most part, sustained via behavioral management of diet and physical activity. At year 1, the lifestyle program produced a mean body weight reduction of 8.5%. Over the next four years, a gradual regaining of weight was observed, followed by the maintenance of losses of approximately 4-5% in subsequent years. At year 8, the lifestyle program participants sustained on average more than half (55%) of their year 1 weight losses. Moreover, the majority succeeded in achieving reductions in body weight of 5% or more. Look AHEAD’s findings stand in contrast to those of prior trials showing that participants regain the majority of lost weight within 3-5 years. The success of Look AHEAD is likely due to the intensive and comprehensive nature of the lifestyle intervention, and confidence in the study’s findings is underscored by the trial’s excellent rate of retention (i.e., more than 88% of the study’s 5,145 participants completed the year 8 assessment). The weight changes observed in Look AHEAD were accomplished in a diverse sample of participants. Thirty-seven percent were selfidentified as members of ethnic or racial minority groups, and more than 40% were men. Prior trials have been less inclusive with respect to ethnic/racial and gender representation, and it has commonly been assumed that non-white participants achieve poorer outcomes in lifestyle programs. While non-Hispanic whites in Look AHEAD had larger year 1 weight losses, subsequent assessments at years 4 and 8 showed comparable weight reductions for the four ethnic/racial groups in the study (African American, Hispanic, American Indian/ Other, and non-Hispanic white participants). The Look AHEAD findings also indicated that men and women had comparable weight loss outcomes at all assessment points. These results show that the lifestyle intervention produced long-term weight losses independent of the participant’s race, ethnicity, or gender. However, older participants (those 66-76 years at baseline) had somewhat greater weight losses than younger ones (age groups: 45-55 and 56-65 years), particularly at year 8, but it is difficult to discern whether this difference was due to the effects of aging and disease progression or to greater adherence among older participants. Relatedly, it is unknown whether the patterns of long-term weight changes observed in Look AHEAD are generalizable to younger adults (ages 21-44 years) and to individuals who do not have diabetes. The problem of poor maintenance of lost weight has been one of the greatest challenges associated with lifestyle interventions. The Look AHEAD findings demonstrate that a substantial degree of long-term weight loss is possible. However, the achievement of that outcome appears to require intensive, ongoing care, based on sound behavioral principles. It has long been recognized that the prescription of changes in diet and exercise, without clinical decision making based on behavioral theory and analysis, is unlikely to produce long-term changes in body weight. The lifestyle intervention in Look AHEAD included a comprehensive array of empirically supported behavioral treatment components, individually tailored through the use of problem-solving and “tool box” strategies, and delivered via structured programs of ongoing group and individual contacts.

Influence of dietary protein intake and glycemic index on the association between TCF7L2 HapA and weight gain

Genetic polymorphisms of transcription factor 7-like 2 (TCF7L2) have been associated with type 2 diabetes and BMI. The objective was to investigate whether TCF7L2 HapA is associated with weight development and whether such an association is modulated by protein intake or by the glycemic index (GI). The investigation was based on prospective data from 5 cohort studies nested within the European Prospective Investigation into Cancer and Nutrition. Weight change was followed up for a mean (±SD) of 6.8 ± 2.5 y. TCF7L2 rs7903146 and rs10885406 were successfully genotyped in 11,069 individuals and used to derive HapA. Multiple logistic and linear regression analysis was applied to test for the main effect of HapA and its interaction with dietary protein or GI. Analyses from the cohorts were combined by random-effects meta-analysis. HapA was associated neither with baseline BMI (0.03 ± 0.07 BMI units per allele; P = 0.6) nor with annual weight change (8.8 ± 11.7 g/y per allele; P = 0.5). However, a previously shown positive association between intake of protein, particularly of animal origin, and subsequent weight change in this population proved to be attenuated by TCF7L2 HapA (P-interaction = 0.01). We showed that weight gain becomes independent of protein intake with an increasing number of HapA alleles. Substitution of protein with either fat or carbohydrates showed the same effects. No interaction with GI was observed. TCF7L2 HapA attenuates the positive association between animal protein intake and long-term body weight change in middle-aged Europeans but does not interact with the GI of the diet.

Maternal stress and high-fat diet effect on maternal behavior, milk composition, and pup ingestive behavior

Chronic variable prenatal stress or maternal high-fat diet results in offspring that are significantly heavier by the end of the first postnatal week with increased adiposity by weaning. It is unclear, however, what role maternal care and diet play in the ontogenesis of this phenotype and what contributions come from differences already established in the rat pups. In the present studies, we examined maternal behavior and milk composition as well as offspring ingestive behavior. Our aim was to better understand the development of the obese phenotype in offspring from dams subjected to prenatal stress and/or fed a high-fat (HF) diet during gestation and lactation. We found that dams maintained on a HF diet through gestation and lactation spent significantly more time nursing their pups during the first postnatal week. In addition, offspring of prenatal stress dams consumed more milk at postnatal day (PND) 3 and offspring of HF dams consume more milk on PND 7 in an independent ingestion test. Milk from HF dams showed a significant increase in fat content from PND 10–21. Together these results suggest that gestational dietary or stress manipulations can alter the rat offspring's developmental environment, evidence of which is apparent by PND 3. Alterations in maternal care, milk composition, and pup consumption during the early postnatal period may contribute to long-term changes in body weight and adiposity induced by maternal prenatal stress or high-fat diet.

The Trp64Arg Polymorphism of the β3-adrenergic Receptor Gene is Associated with Weight Changes in obese Japanese Men: A 4-year Follow-up Study

The aim of this study was to investigate whether the Trp64Arg polymorphism of the beta(3)-adrenergic receptor gene (ADRB3) is associated with weight changes in obese Japanese men at 4-year follow-up. The participants were 145 obese Japanese men [age: 35.8+/-5.3 y; body mass index (BMI): 27.5+/-3.3 kg/m(2)]. The participants were divided into two groups according to the Trp64Arg genotype: (1) with the Arg64 allele of the ADRB3 (Trp64Arg and Arg64Arg genotypes, n=50); (2) without the Arg64 allele of the ADRB3 (Trp64Trp genotype, n=95). The ADRB3 genotyping was performed by denaturing high performance liquid chromatography (DHPLC). Body weight, BMI, and blood pressure were determined at baseline and at 4 years. After 4 years, the participants with the Arg allele of the ADRB3 significantly increased their body weight (2.1+/-4.7 kg, p=0.002) and BMI (0.64+/-1.6 kg/m(2), p=0.006) whereas the participants without the Arg allele of the ADRB3 did not significantly change in these parameters (body weight: -0.36+/-4.2 kg, p=0.41; BMI: -0.24+/-1.5 kg/m(2), p=0.12). The results in this study showed that the Arg allele of the ADRB3 is associated with long-term changes in body weight in obese individuals. This polymorphism may become an indicator in personalized weight loss programs in obese men.

Long-term changes in body weight following complete fasting for obesity.

Journal Article Long-Term Changes in Body Weight Following Complete Fasting for Obesity Get access Nutrition Reviews, Volume 25, Issue 6, June 1967, Pages 168–170, https://doi.org/10.1111/j.1753-4887.1967.tb05622.x Published: 01 June 1967

β3-Adrenoceptor function and long-term changes in body weight

The endogenous factors contributing to long-term changes in body weight are not known but the regulation of energy metabolism by different beta-adrenoceptors (beta(1)-AR, beta(2)-AR, beta(3)-AR) or alpha-adrenoceptors (alpha(2)-AR) may play a role. In a prospective study, we investigated beta-AR and alpha(2)-AR subtype function in subcutaneous fat cells of 85 healthy, non-obese women by using a standardized bioassay of lipolysis. Of these 73 were re-investigated on an average 10 years later to compare baseline function of beta(1)-AR, beta(2)-AR, beta(3)-AR and alpha(2)-AR with longitudinal weight changes. Weight change over time was normally distributed ranging from-4 kg/m(2) to +6 kg/m(2) in body mass index. Long-term changes in body weight correlated inversely with beta(3)-AR function at base line (r=0.5, P=0.001). Those with low beta(3)-AR function gained weight, whereas the opposite was observed with those who had a high beta(3)-AR function. Nineteen percent of weight changes could be explained by beta(3)-AR status. No relationship with weight changes was observed as regards the function of alpha(2)-AR, beta(1)-AR or beta(2)-AR function. Beta(3)-ARs are important for long-term changes in body weight putting energy metabolism in adipose tissue in frontline among endogenous factors that regulate body weight in adulthood.

Relation of long-term body weight change to change in lipoprotein particle size in Japanese men and women: The INTERMAP Toyama Study

ObjectiveThis study investigated the relationship between changes in lipoprotein particle size and body weight change over a 9-year period in Japanese adult men and women. MethodsAmong 299 INTERMAP Toyama Study participants aged 40–59 in 1997, 260 were followed up in 2006 (129 men and 131 women). Their body weight and lipoprotein particle sizes were measured in 1997 and 2006. Nuclear Magnetic Resonance spectroscopy was used for the measurement of lipoprotein particle size. ResultsThe number of small LDL particles decreased from 774.3 to 617.4nmol/L in men (p=0.005) while the number increased from 353.2 to 414.5nmol/L in women (p=0.028) over this period. No significant changes in mean body weight were noted in either sex. Nine-year body weight change was positively associated with changes in the numbers of small LDL particles (men, r=0.37, p<0.001; women, r=0.21, p=0.018), but inversely associated with changes in LDL particle size (men, r=−0.30, p=0.001; women, r=−0.16, p=0.066) and HDL particle size (men, r=−0.42, p<0.001; women, r=−0.42, p<0.001). These relationships were similar even when adjusted for age, baseline body mass index, baseline values for LDL and HDL particle sizes, and other factors. The number of small LDL particles increased in both men and women in the body weight gain group. In the body weight loss group, the number of small LDL particles decreased in men but did not decrease in women. ConclusionThis 9-year observational study showed that the number and size of lipoprotein particles were strongly influenced by long-term body weight change.

Insurance Coverage and Incentives for Weight Loss Among Adults With Metabolic Syndrome

To describe how insured adults with metabolic syndrome respond to various options for insurance coverage and financial incentives for weight management. Insured adults meeting the criteria for the metabolic syndrome were randomly identified through automated medical records and invited to participate in a telephone-based survey of the acceptability of various weight management programs-with different financial incentives and insurance coverage options-in a health maintenance organization. Multivariable logistic regression models were used to test the relationship between participant characteristics and the odds of being motivated by incentives. One hundred and fifty-three adults with the metabolic syndrome completed the survey (i.e., 79% of telephone contacts). A hypothetical increase in insurance coverage from 10 to 100% led to a threefold increase among women and a sevenfold increase among men in the proportion reporting they were "very interested" in enrolling in a weight management program within the next 30 days. Most participants (76% of women and 57% of men) supported a health plan-sponsored financial incentive program tied to weight loss, and 41% believed such a program would motivate them to lose weight. The mean financial incentive proposed for a 15-pound weight loss was $591 (median: $125). Although weight loss is an effective treatment for metabolic syndrome, standard health insurance rarely covers intensive behavioral treatment. The results of this study suggest that providing full insurance coverage and financial incentives for weight management increases the interest in participating in obesity treatment programs. Further research should determine how full coverage and incentives affect participation rates, long-term body weight changes, and costs.

Long-term changes in body weight, BMI, and adiposity rebound among children and adolescents in the Czech republic

The Czech Republic has undergone rapid political, social, and economic transformation since the late 1980s. While obesity rates among children and adolescents in the Czech Republic have been previously relatively low, this has changed in recent years. Across the past 50 years, body weight, body mass index (BMI)-for-age, and adiposity rebound (AR) (the time when a child reaches the lowest BMI before their BMI gradually begins to increase until adulthood) occurs earlier. The most dramatic changes have been observed among school-aged children, where BMI values have increased at the 50th, 90th, and 97th percentiles. In contrast, adolescent girls appear to be thinner than in the past. The analyses of weight-for-height percentiles indicated that the 50th percentile of the body weight among boys and girls remained similar in nearly all age categories across the past 50 years. Although the growth pattern of children at the 50th percentile has not changed, the 10th and 90th percentiles have expanded. Our findings suggest that the secular trend of increased height, accelerated growth, and earlier maturation is responsible for Czech children experiencing adiposity rebound at earlier ages compared to the past.

The Effect of Exercise Dose and Healthy Eating Recommendations on Long-Term Changes in Body Weight

PURPOSE: To examine varying doses of exercise combined with healthy eating recommendations on long-term body weight change in moderately overweight adults. METHODS: One hundred sixty three (age = 45.3+7.8 year; BMI = 27.1+1.7 kg/m2) overweight individuals who have completed an 18-month intervention were randomly assigned to information control group (CON), moderate exercise (MOD) or high exercise (HIGH). CON received general health content including the health benefits of 30 min/d of physical activity. MOD progressed exercise to 150 min/wk; HIGH progressed exercise to 300 min/wk. MOD and HIGH attended behavioral meetings, received intervention phone calls, attended at least 1 supervised exercise session per week, and were instructed to eat a healthy diet but not encouraged to reduce energy intake. Weight and physical activity were assessed at 0, 6, and 18 months. RESUITS: Physical activity was significantly different between groups at 6 months (CON=1581+1037 kcal/wk; MOD=1728+757kcal/wk, HIGH=2382+1186 kcal/wk) and 18 months (CON=1415+925 kcal/wk; MOD=1361+830 kcal/wk, HIGH=1917+1189 kcal/wk) (p<0.05). Modest weight loss was observed at 6 months (CON=−0.7+4.5 kg; MOD=−0.8+4.5 kg, HIGH=−1.6+3.7 kg) and 18 months (CON=−0.5+3.6 kg; MOD=−1.2+4.1 kg, HIGH=−1.0+4.2kg), with no significant difference between groups. Subjects were also grouped on weekly physical activity at 6 and 18 months: <1500 kcal/week at 6 and 18 months (NON-ADOPT), >1500 kcal/week at 6 months and <1500 kcal/week at 18 months (NON-MAINTAIN), >1500 kcal/week at 6 and 18 months (MAINTAIN), and <1500 kcal/wk at 6 months and >1500 kcal/wk at 18 months (LATE ADOPT), with 26%, 29%, 38%, and 7% of subjects in these groups, respectively. There was a trend (p<0.10) for differences in weight change at 18 months of-1.9+4.2 kg, (MAINTAIN), −0.6+3.9 kg (NON-MAINTAIN), −0.5+4.2 kg (LATE ADOPT), and −0.1+3.6 kg (NON-ADOPT). CONCLUSION: 150 to 300 min/wk of moderate intensity physical activity elicits modest long-term weight loss in overweight adults. However, adoption and maintenance of higher levels of physical activity results in a trend towards greater weight loss. These results may have implications for prevention of weight gain and additional health benefits for overweight adults. Supported by the National Institutes of Health (HL070257)

Energy balance pathways converging on the Nhlh2 transcription factor

Multiple regulatory pathways exist to control the expression levels of neuropeptides in response to body weight and energy availability changes. Since many neuropeptides are first synthesized in a pro-neuropeptide form, the availability of processing enzymes in a neuron can control the amount of active mature neuropeptide produced at any given time. In this review, we will focus on the regulation of prohormone convertase 1 (PC1) and prohormone convertase 2 (PC2), as well as downstream neuropeptide genes. Evidence from our laboratory suggests that Nescient helix-loop-helix 2 (Nhlh2) regulates the transcription of PC1 and PC2, possibly in conjunction with the leptin-stimulated transcription factor, STAT3. Furthermore, Nhlh2 itself is a target of leptin and other energy availability signals, with high levels of expression during energy surplus, and low levels of expression in conditions of reduced energy availability such as food deprivation or cold exposure. Overall, coordinate regulation of Nhlh2, PC1, PC2 and downstream hypothalamic neuropeptides such as thyrotropin releasing hormone (TRH) and pro-opiomelanocortin (POMC) does lead to energy balance modulation and ensuing long-term changes in body weight.

Impact of prenatal stress on long term body weight is dependent on timing and maternal sensitivity

Stress experienced during pregnancy increases the risk for altered birth weights. Recent studies have revealed a link between abnormal birth weights and a future predisposition toward developing overweight or obesity. To determine the gestational time window when stress exposure produces the greatest impact on offspring body weight regulation, we have examined the birth weights and long-term body weight changes in offspring exposed to chronic variable stress (CVS) early, mid-, or late in gestation. As it is likely that the influences of prenatal stress on development stem from a complex interaction between both environmental and genetic factors, our study has included comparisons with offspring born to stress-sensitive (corticotropin-releasing factor receptor-2 deficient) mice. Stress experienced late in pregnancy significantly elevated offspring birth weights in wild type mice compared to unstressed controls. However, this weight difference diminished postnatally. In contrast, stress experienced mid- to late in pregnancy produced significant and long-term effects on body weight in offspring from stress-sensitive dams, were the male offspring were 15% heavier as adults. Adult offspring plasma glucose and leptin levels were also dependent on the timing of stress exposure, indicating that alterations in energy homeostasis may be influencing long-term body weight. Results from these studies support our hypothesis that the ultimate effect of prenatal stress on offspring long-term outcome is dependent on the timing of exposure and maternal sensitivity.

Gut Hormone Profiles Following Bariatric Surgery Favor an Anorectic State, Facilitate Weight Loss, and Improve Metabolic Parameters

To study the effect of bariatric surgery on the entero-hypothalamic endocrine axis of humans and rodents. Bariatric surgery is the most effective obesity treatment as it achieves substantial and sustained weight loss. Glycemic control and enhanced satiation improve before substantial weight loss occurs. Gut peptides, acting both peripherally and centrally, contribute to glycemic control and regulate food intake. We examined meal-stimulated responses of insulin, ghrelin, peptide YY (PYY), glucagon-like-peptide-1 (GLP-1), and pancreatic polypeptide (PP) in humans and rodents following different bariatric surgical techniques. Compared with lean and obese controls, patients following Roux-en-Y gastric bypass (RYGB) had increased postprandial plasma PYY and GLP-1 favoring enhanced satiety. Furthermore, RYGB patients had early and exaggerated insulin responses, potentially mediating improved glycemic control. None of these effects were observed in patients losing equivalent weight through gastric banding. Leptin, ghrelin, and PP were similar in both the surgical groups. Using a rodent model of jejuno-intestinal bypass (JIB), we showed elevated PYY and GLP-1 in JIB rats compared with sham-operated rats. Moreover, exogenous PYY reduced food intake and blockade of endogenous PYY increased food intake. Thus, higher plasma PYY following JIB may contribute to reduced food intake and contribute to weight loss. Following RYGB and JIB, a pleiotropic endocrine response may contribute to the improved glycemic control, appetite reduction, and long-term changes in body weight.

Serum adiponectin concentrations during a 72-hour fast in over- and normal-weight humans

Adiponectin is currently considered an important link between obesity and insulin resistance, since circulating levels of this insulin sensitizing hormone have consistently been found to be reduced in obese subjects. However, until now it is not known how the secretion of adiponectin is regulated in response to acute metabolic changes. Here, we assessed the influence of complete fasting for 72 h on serum adiponectin levels. Between group comparison of repeated measurements. In total, 18 normal-weight (mean+/-s.e.m. BMI: 22.2+/-0.4 kg/m(2); age: 39.2+/-4.4 y) and nine over-weight (BMI: 33.2+/-1.8 kg/m(2); age: 36.9+/-4.5 y) subjects. Serum adiponectin levels were measured every 4 h during a 72-h fasting period. Additionally, concentrations of plasma glucose and serum insulin and leptin were assessed at the beginning and in the end of the fasting experiment. Insulin resistance was estimated using the homeostasis model assessment (HOMA). While concentrations of glucose, insulin, and leptin decreased across the fasting period by 31.0, 33.1 and 60.0%, respectively (all P<0.005), adiponectin levels remained unchanged (P=0.817). Overall, over-weight subjects exhibited slightly lower adiponectin levels than normal-weight subjects (P=0.092), but there was no difference in the time course of adiponectin levels during fasting between these two groups (P=0.970). Although, averaged adiponectin levels before and after fasting did not systematically differ, individual changes in adiponectin levels across fasting displayed a slight but significant inverse correlation with changes in plasma glucose concentration (r=-0.42, P=0.03). The data show that serum adiponectin concentrations remain remarkably stable during 72 h of fasting in normal- and over-weight subjects. Thus, adiponectin appears to reflect primarily long-term changes in body weight with little evidence for a dependence on short-term regulatory influences.

Modifications in food-group consumption are related to long-term body-weight changes

Dietary patterns play an important role in the control of body weight. The aim of this study was to verify whether changes in some dietary patterns over a 6-y follow-up period would be associated with weight changes. A sample of 248 volunteers of the Québec Family Study were measured twice (visit 1: 1989-1994; visit 2: 1995-2000). Body weight, percentage body fat, subcutaneous skinfold thicknesses, and waist circumference measurements as well as 3-d dietary and physical activity records were obtained at each visit. At visit 2, all participants filled out a food-based questionnaire examining changes in the consumption of 10 food categories. To further investigate the relation between changes in food-group consumption and body-weight changes, a total of 51 food subcategories were identified from dietary records. A self-reported decrease in the consumption of food in the fat group or an increase in consumption in the fruit group from the food-based questionnaire predicted a lower increase in body weight and adiposity indicators over time. A more detailed examination of the change in food groups between diet records revealed that increases in the consumption of whole fruit as well as skimmed milk and partly skimmed milk were the 2 food patterns that negatively correlated with the changes of each body weight-related indicator. These results show that changes in the consumption of some specific food groups are associated with body-weight changes. Such specific eating patterns could help to improve obesity treatment and prevention.

Effect of long-term body weight change on the incidence of hypertension in Japanese men and women.

To elucidate the effect of long-term body weight changes on the subsequent incidence of hypertension in a large sample of community-residing Japanese males and females. Subjects were 3431 men and 2409 women, between 30 and 69 y old, who underwent annual periodic health examinations from 1987 (baseline year) until 1996. They were free from hypertension during the first 5 y from the baseline year. Body weight change index between 1987 and 1992 was the body mass index (BMI) (weight (kg) over height (m) squared) slope. Multiple logistic analysis was performed to assess the effect of BMI slope on the incidence of hypertension during the subsequent 5 ys (1992-1996), while controlling for baseline age, BMI, systolic blood pressure (SBP), diastolic blood pressure (DBP) and smoking habit. During the first 5 y, the prevalence of overweight males (25.0< or =BMI<30.0) significantly increased from 18.4 to 23.5% in males and from 10.4 to 14.1% in females. In all, 11.7% of the males and 8.9% of the females developed hypertension between 1992 and 1996. Those who developed hypertension had a significantly higher baseline age, BMI, SBP and DBP both in males and females. The baseline smoking rate among the females who developed hypertension was significantly lower than those who did not develop the hypertension. After adjustment of these covariables by the multiple logistic analysis, the BMI slope was positively correlated with the incidence of hypertension both in females and males significantly. Weight gain increased the risk of developing hypertension independent of age and blood pressure level among relatively lean Japanese men and women.

Links between the appetite regulating systems and the neuroendocrine hypothalamus: lessons from the sheep.

The hypothalamus is integral to the regulation of energy homeostasis and the secretion of hormones from the pituitary gland. Consequently, hypothalamic systems may have a dual purpose in regulating both neuroendocrine function and appetite. To date, most studies investigating the interface between appetite and hormone secretion have been performed in rats or mice that have been acutely fasted or baring a genetic abnormality causing either obesity or aphagia. By contrast, various physiological models, including chronic food-restriction or photoperiodically driven changes in voluntary food intake, add further perspective to the issue. In this regard, sheep provide an innovative model whereby long-term changes in body weight or extended feeding rhythms can be investigated. This review compares and contrasts data obtained in different species with regard to the neuroendocrinology of appetite, and discusses the benefits and knowledge gained from using various nonrodent models with a particular emphasis on a ruminant species.

A preexercise alpha-lactalbumin-enriched whey protein meal preserves lipid oxidation and decreases adiposity in rats.

The composition of the preexercise food intake is known to affect substrate utilization during exercise and thus can affect long-term changes in body weight and composition. These parameters were measured in male rats exercised 2 h daily over 5 wk, either in the fasting state or 1 h after they ingested a meal enriched with glucose (Glc), whole milk protein (WMP), or alpha-lactalbumin-enriched whey protein (CPalphaL). Compared with fasting, the Glc meal increased glucose oxidation and decreased lipid oxidation during and after exercise. In contrast, the WMP and CPalphaL meals preserved lipid oxidation and increased protein oxidation, the CPalphaL meal increasing protein oxidation more than the WMP meal. At the end of the study, body weight was larger in the WMP-, Glc-, and CPalphaL-fed rats than in the fasted ones. This resulted from an increased fat mass in the WMP and Glc rats and to an increased lean body mass, particularly muscles, in the CPalphaL rats. We conclude that the potential of the CPalphaL meal to preserve lipid oxidation and to rapidly deliver amino acids for use during exercise improved the efficiency of exercise training to decrease adiposity.

Effect of a three-amino acid deletion in the alpha2B-adrenergic receptor gene on long-term body weight change in Finnish non-diabetic and type 2 diabetic subjects.

The short form (Glu9/Glu9) of the 12Glu9 deletion polymorphism of the alpha2B-adrenergic receptor gene was previously found to be associated with reduced basal metabolic rate in obese subjects. We investigated the effects of this polymorphism on changes in body weight in Finnish non-diabetic and type 2 diabetic subjects during a 10 y follow-up. Controlled 10 y follow-up study with baseline, 5 and 10 y examinations. A total of 126 non-diabetic control subjects and 84 newly diagnosed, middle-aged type 2 diabetic patients from eastern Finland participated. Anthropometric measurements, blood pressure, oral glucose tolerance test, plasma insulin, plasma C-peptide and glycosylated hemoglobin A1c. Genotypes were determined by polymerase chain reaction followed by agarose gel electrophoresis. No significant differences were found in the prevalence of the 12Glu9 deletion polymorphism between non-diabetic and type 2 diabetic subjects. The non-diabetic subjects with the Glu9/Glu9 genotype had a greater increase in their mean body weight during 5 y follow-up than the non-diabetic subjects with other genotypes (changes in body weight 0.4+/-5.7, -0.5+/-6.4 and 3.4+/-4.9% for the Glu12/Glu12, Glu12/Glu9 and Glu9/Glu9 genotypes, respectively, P=0.040 for the difference between the groups). Also, the trend for the increment of body weight was statistically significant in the non-diabetic subjects with the Glu9/Glu9 genotype (P=0.012). The 12Glu9 polymorphism was not cross-sectionally or longitudinally associated with body weight in type 2 diabetic subjects. The genotype of two short alleles (Glu9/Glu9) was associated with an increase in body weight among non-diabetic subjects.

Obesity and weight change related to parity and breast-feeding among parous women in Brazil.

Studies on the independent role of parity in long-term body weight change in economically developing countries are scarce and inconclusive, and only a few studies have taken into account patterns of breast-feeding. This association was examined in a national cross-sectional survey representative of Brazilian parous women. The survey conducted in 1996 measured women's height and weight in the household and data on weight prior to the first pregnancy, parity and breast-feeding were recalled. A sample of 2338 parous women, 15 to 49 years of age, 29 months after last delivery on average, had current body mass index (BMI, in kg m(-2)) modelled through hierarchical multiple linear regression analysis. Explanatory variables included parity, days of predominant breast-feeding, BMI pre-pregnancy, socio-economic, geographic, demographic and other reproductive variables. Prevalences of overweight (BMI = 25.0-29.9 kg m(-2)) and obesity (BMI > or = 30.0 kg m(-2)) were 25.2% and 9.3%. The overall mean weight gain per year after the first pregnancy was 0.90 kg for an average time since first pregnancy of eight years. BMI pre-pregnancy modified the association between current BMI and parity. Therefore, weight change attributed to parity calculated for a woman of average height (1.56 m) was 0.60 kg greater for primiparous women with a BMI pre-pregnancy of 30 kg m(-2), compared with women with BMI pre-pregnancy of 25 kg m(-2). This greater weight retention among obese women was 1.21 kg for women with two children and 1.82 kg for women with three or more children. Parity reduced the effect of weight loss associated with lactation (1.75 kg for six months of lactation among primiparous women and 0.87 kg among women with three or more children). For the sub-sample of 793 primiparous women, a weight decrease of 300 g was associated with each month of predominant breast-feeding for all prior BMI levels. In this study, weight change associated to reproduction was highly dependent on BMI previous to pregnancy and the effects of parity and lactation were small.