Effects of weight loss by diet alone or combined with aerobic exercise on body composition in older obese men

2020 Korean Society for the Study of Obesity Guidelines for the Management of Obesity in Korea

Obesity is a prevalent and complex disease. The prevalence of obesity in Korea increased from 29.7% in 2010 to 35.7% in 2018, with the prevalence of abdominal obesity being 23.8% in 2018. Obesity contributes to medical costs and socioeconomic burden due to associated comorbidities. The treatment and management of obesity is changing based on new clinical evidence. The 2020 Korean Society for the Study of Obesity Guideline for the Management of Obesity in Korea summarizes evidence-based recommendations and treatment guidelines.

[Problems of optimal nutrition of elderly and senile patients with comorbidities against obesity]

AIM

To analyze the effectiveness of the main and low - calorie standard diets in elderly and senile patients with comorbidities against obesity.

MATERIALS AND METHODS

Retrospective analysis of the inpatient data. Patients received the main or low - calorie standard diet at the Nutrition clinic. The analysis included clinical, laboratory, body composition (bioimpedance) parameters and the results of indirect calorimetry. The primary endpoint was anthropometric and body composition data. Statistical analysis was performed using Statistica 10.0 for Windows 6.1 (StatSoft Inc., USA).

RESULTS AND DISCUSSION

46 patients were included in the analysis. The average age was 65 years (95% CI 63.63-66.37 years). All patients had abdominal obesity. 44 patients (97.78%) had hypertension, 32 (71.11%) - osteoarthrosis, 28 (60.87%) - dyslipidemia, 16 (35.56%) - diabetes mellitus; and сoronary artery disease was detected in 9 patients (20%). Diet therapy caused a statistically significant decrease in body weight, waist and hip circumferences, fat mass, lean mass, total body fluid and muscle mass (in particular, 25.35% weight loss was due to muscle mass loss), as well as the improvement of lipid profile.

CONCLUSION

Dietary interventions, such as main and low - calorie standard diets, routinely used for inpatient settings allow us to reduce body weight and improve anthropometric parameters in elderly and senile obese patients with comorbidities, which is accompanied by positive changes in lipid and carbohydrate metabolism even in a short - term follow - up. However, the protein content for standard diets is insufficient for this target group and leads to the loss of both fat and muscle mass.

Effect of a Whey Protein Supplement on Preservation of Fat Free Mass in Overweight and Obese Individuals on an Energy Restricted Very Low Caloric Diet

The obesity epidemic has caused a widespread interest in strategies to achieve a healthy "high quality" weight loss, where excess fat is lost, while fat free mass (FFM) is preserved. In this study, we aimed to examine the effect of whey protein supplementation given before night sleep on FFM preservation during a 4-week (wk) period on a very low caloric diet (VLCD). Twenty-nine obese subjects (body mass index (BMI) > 28 kg/m²) completed a 4-week intervention including a VLCD and a walking program (30 min walking × 5 times per week). Subjects were randomly assigned to either control (CON, n = 15) or a whey protein supplement (PRO, 0.4 g protein/kg/day, n = 14), ingested before bedtime. Body composition (dual-energy X-ray absorptiometry, DXA), blood analysis and physical test were performed pre and post intervention. We measured nitrogen excretion in three 24 h urine collections (Day 0, 7 and 28) to assess nitrogen balance. Changes in nitrogen balance (NB) after 7 and 28 days was different between treatment groups (interaction p < 0.05). PRO was in NB after 7 days and in positive NB at day 28. In contrast, CON was in negative NB at day 7, but in NB at day 28. Nevertheless, no significant group differences were observed in the change in pre- and post-FFM measurements (-2.5 kg, [95% CI: 1.9; 3.1], p = 0.65). In conclusion, ingestion of a whey protein supplement before bedtime during a 4-week period on a VLCD improved nitrogen balance, but did not lead to any significant improvement in the quality of the weight loss in regard to observed changes in body composition and health parameters compared with controls.

Effects of prolonged exercise versus multiple short exercise sessions on risk for metabolic syndrome and the atherogenic index in middle-aged obese women: a randomised controlled trial

BACKGROUND

Many people, although they may recognise the positive effects of exercise, do not exercise regularly owing to lack of time. This study aimed to investigate the effects of prolonged single-session exercise and multiple short sessions of exercise on the risk of metabolic syndrome and the atherogenic index in middle-aged obese women.

METHODS

Thirty-six participants were divided into the single-session group, multiple-session group, and control group. The single-session group engaged in one session of treadmill exercise for 30 min a day; the multiple-session group had three sessions of 10 min a day. Both groups exercised 3 days/week for 12 weeks. The control group did not perform any exercise.

RESULTS

The single-session group showed decreases in weight (0.97 kg [95% C.I. = 0.09-1.83], p < .05), body mass index (0.43 kg/m2 [95% C.I. = 0.03-0.81], p < .05), and fat mass (1.65 kg, [95% C.I. = 0.78-2.51], p < .01). Systolic blood pressure dropped in the single-session group (6.66 mmHg, [95% C.I. = 1.44-11.88], p < .05), and diastolic blood pressure dropped in the multiple-session group (3.38 mmHg, [95% C.I. = 1.44-5.88], p < .01). High-density lipoprotein cholesterol rose in the single-session group (4.08 mg/dL, [95% C.I. = -8.08-(-)0.07], p < .05) and dropped in the control group (10.75 mg/dL [95% C.I. = 1.95-19.54], p < .01). According to post hoc analysis, high-density lipoprotein cholesterol increased more in the single-session group than the control group (95% C.I. = 0.61-21.88, p < .05). Glucose levels decreased in both the single-session group (16 mg/dL [95% C.I. = 5.64-26.35], p < .01) and the multiple-session group (12.16 mg/dL, [95% C.I. = 2.18-22.14], p < .05). Waist circumference decreased in the single-session group (2.65 cm [95% C.I. = 1.46-3.83], p < .001) and multiple-session group (2.04 cm, [95% C.I. = 1.51-2.73], p < .001). Low-density lipoprotein cholesterol levels rose in both the multiple-session group (-15.79 mg/dL [95% C.I. = -34.24-(-)3.78], p < .05) and the control group (-22.94 mg/dL [95% C.I. = -44.63-(-)1.24], p < .05). The atherogenic index increased in the control group (-1.06 [95% C.I. = -1.69-(-)0.41], p < .01).

CONCLUSIONS

The findings indicate that prolonged exercise is superior to multiple short sessions for improving the risk of metabolic syndrome and the atherogenic index in middle-aged obese women. However, multiple short sessions can be recommended as an alternative to prolonged exercise when the goal is to decrease blood glucose or waist circumference.

Does the method of weight loss effect long-term changes in weight, body composition or chronic disease risk factors in overweight or obese adults? A systematic review

BACKGROUND

Differences in biological changes from weight loss by energy restriction and/or exercise may be associated with differences in long-term weight loss/regain.

OBJECTIVE

To assess the effect of weight loss method on long-term changes in weight, body composition and chronic disease risk factors.

DATA SOURCES

PubMed and Embase were searched (January 1990-October 2013) for studies with data on the effect of energy restriction, exercise (aerobic and resistance) on long-term weight loss. Twenty articles were included in this review.

STUDY ELIGIBILITY CRITERIA

Primary source, peer reviewed randomized trials published in English with an active weight loss period of >6 months, or active weight loss with a follow-up period of any duration, conducted in overweight or obese adults were included.

STUDY APPRAISAL AND SYNTHESIS METHODS

Considerable heterogeneity across trials existed for important study parameters, therefore a meta-analysis was considered inappropriate. Results were synthesized and grouped by comparisons (e.g. diet vs. aerobic exercise, diet vs. diet + aerobic exercise etc.) and study design (long-term or weight loss/follow-up).

RESULTS

Forty percent of trials reported significantly greater long-term weight loss with diet compared with aerobic exercise, while results for differences in weight regain were inconclusive. Diet+aerobic exercise resulted in significantly greater weight loss than diet alone in 50% of trials. However, weight regain (∼ 55% of loss) was similar in diet and diet+aerobic exercise groups. Fat-free mass tended to be preserved when interventions included exercise.

Obesity in Older Adults: Technical Review and Position Statement of the American Society for Nutrition and NAASO, The Obesity Society

Obesity causes serious medical complications and impairs quality of life. Moreover, in older persons, obesity can exacerbate the age-related decline in physical function and lead to frailty. However, appropriate treatment for obesity in older persons is controversial because of the reduction in relative health risks associated with increasing body mass index and the concern that weight loss could have potential harmful effects in the older population. This joint position statement from the American Society for Nutrition and NAASO, The Obesity Society reviews the clinical issues related to obesity in older persons and provides health professionals with appropriate weight-management guidelines for obese older patients. The current data show that weight-loss therapy improves physical function, quality of life, and the medical complications associated with obesity in older persons. Therefore, weight-loss therapy that minimizes muscle and bone losses is recommended for older persons who are obese and who have functional impairments or medical complications that can benefit from weight loss.

Association Between Body Fat Response to Exercise Training and MultilocusADRGenotypes

OBJECTIVE

To examine the contribution of adrenergic receptor (ADR) gene polymorphisms and their gene-gene interactions to the variability of exercise training-induced body fat response.

RESEARCH METHODS AND PROCEDURES

This was an intervention study that used a volunteer sample of 70 healthy, sedentary men (n = 29) and postmenopausal women (n = 41) 50 to 75 years of age, with a BMI < or = 37 kg/m2, from the Washington, DC, metropolitan area. Participants completed 6 weeks of dietary stabilization (American Heart Association diet) before 24 weeks of supervised aerobic exercise training. Diet was maintained throughout the intervention. Change in percent total body fat, percent trunk fat, and fat mass by DXA in ADR genotype groups (Glu12/Glu9 alpha2b-ADR, Trp64Arg beta3-ADR, and Gln27Glu beta2-ADR) at baseline and after 24 weeks of aerobic exercise training was measured.

RESULTS

In multivariate analysis (covariates: age, gender, and baseline value of phenotype), best fit models for percent total body and trunk fat response to exercise training retained main effects of all three ADR gene loci and the effects of each gene-gene interaction (p = 0.009 and 0.003, respectively). Similarly, there was a trend for the fat mass response model (p = 0.03). The combined genetic factors explained 17.5% of the overall model variability for percent total body fat, 22% for percent trunk fat, and 10% for fat mass.

DISCUSSION

The body fat response to exercise training in older adults is associated with the combined effects of the Glu12/Glu9 alpha2b-, Trp64Arg beta3-, and Gln27Glu beta2-ADR gene variants and their gene-gene interactions.

Obesity and the elderly

The prevalence of obesity is rising progressively, even among older age groups. By the year 2030 to 2035 over 20% of the adult US population and over 25% of the Europeans will be aged 65 years or older. The predicted prevalence of obesity in Americans, 60 years and older was 37% in 2010. The predicted prevalence of obesity in Europe in 2015 varies between 20% and 30% dependent on the model used. This means 20.9 million obese 60 years or older people in the United States in 2010 and 32 million obese elders in 2015 in EU. Although cutoff values of body mass index, waist circumference, and percentages of fat mass have not been defined for the elderly, it is clear from several meta-analyses that mortality and morbidity associated with overweight and obesity only increases at a body mass index >30 kg/m(2). Thus, treatment should only be offered to patients who are obese rather than overweight and who have functional impairments, metabolic complications, or obesity-related diseases, that can benefit from weight loss. The weight loss therapy should minimize muscle and bone loss and vigilance as regards the development of sarcopenic obesity--a combination of an unhealthy excess of body fat with a detrimental loss of muscle and fat-free mass including bone--is important. Lifestyle intervention should be the first step and consists of a diet with a 500 kcal energy deficit and an adequate intake of protein of high biological quality, together with calcium and vitamin D, behavioral therapy, and multicomponent exercise. Multicomponent exercise includes flexibility training, balance training, aerobic exercise, and resistance training. The adherence rate in most studies is around 75%. Knowledge of constraints and modulators of physical inactivity should be of help to engage the elderly in physical activity. The role of pharmacotherapy and bariatric surgery in the elderly is largely unknown as in most studies people aged 65 years and older were excluded.

Aerobic training effects on glucose tolerance in prediabetic and normoglycemic humans

INTRODUCTION

It is generally accepted that if prediabetic individuals adopt healthy lifestyle habits, the progression to type 2 diabetes mellitus can be prevented or delayed. However, the role of exercise training independent of other lifestyle factors has not been determined. Furthermore, patients with type 2 diabetes mellitus have been shown to experience greater training-induced changes in glucose and insulin metabolism compared with healthy subjects, but the adaptations of prediabetic individuals have not been adequately examined. We hypothesized that (i) prediabetic subjects would have greater endurance training-induced changes in plasma glucose and insulin responses to an oral glucose challenge compared with age- and body mass index-matched normoglycemic subjects and (ii) training would completely reverse the abnormal glucose metabolism of prediabetic subjects.

METHODS

Plasma glucose and insulin responses to oral glucose tolerance tests (OGTTs) were examined in normoglycemic (n = 119) and prediabetic (n = 47) older men and women before and after a 6-month standardized endurance exercise training program.

RESULTS

Prediabetic subjects had greater glucose and insulin OGTT responses than normoglycemic subjects both before and after training (P < 0.05). Prediabetic subjects had greater training-induced changes in glucose and insulin areas under the glucose tolerance curve, as well as greater changes in glucose and insulin concentrations at several points of the OGTT. However, these changes did not eliminate the baseline differences in glucose tolerance between normoglycemic and prediabetic subjects. The between-group differences in changes in glucose and insulin variables were largely independent of changes in body weight or composition.

CONCLUSIONS

Our data indicate that prediabetes is associated with greater training-induced changes in glucose tolerance. However, 6 months of endurance training alone was not sufficient to completely reverse prediabetes.

Prevalence, pathophysiology, health consequences and treatment options of obesity in the elderly: a guideline

The prevalence of obesity is rising progressively, even among older age groups. By the year 2030-2035 over 20% of the adult US population and over 25% of the Europeans will be aged 65 years and older. The predicted prevalence of obesity in Americans, 60 years and older was 37% in 2010. The predicted prevalence of obesity in Europe in 2015 varies between 20 and 30% dependent on the model used. This means 20.9 million obese 60+ people in the USA in 2010 and 32 million obese elders in 2015 in the EU. Although cut-off values of BMI, waist circumference and percentages of fat mass have not been defined for the elderly (nor for the elderly of different ethnicity), it is clear from several meta-analyses that mortality and morbidity associated with overweight and obesity only increases at a BMI above 30 kg/m(2). Thus, treatment should only be offered to patients who are obese rather than overweight and who also have functional impairments, metabolic complications or obesity-related diseases, that can benefit from weight loss. The weight loss therapy should aim to minimize muscle and bone loss but also vigilance as regards the development of sarcopenic obesity - a combination of an unhealthy excess of body fat with a detrimental loss of muscle and fat-free mass including bone - is important in the elderly, who are vulnerable to this outcome. Life-style intervention should be the first step and consists of a diet with a 500 kcal (2.1 MJ) energy deficit and an adequate intake of protein of high biological quality together with calcium and vitamin D, behavioural therapy and multi-component exercise. Multi-component exercise includes flexibility training, balance training, aerobic exercise and resistance training. The adherence rate in most studies is around 75%. Knowledge of constraints and modulators of physical inactivity should be of help to engage the elderly in physical activity. The role of pharmacotherapy and bariatric surgery in the elderly is largely unknown as in most studies people aged 65 years and older have been excluded.

Is lost lean mass from intentional weight loss recovered during weight regain in postmenopausal women?

BACKGROUND

Despite the well-known recidivism of obesity, surprisingly little is known about the composition of body weight during weight regain.

OBJECTIVE

The objective of this study was to determine whether the composition of body weight regained after intentional weight loss is similar to the composition of body weight lost.

DESIGN

The design was a follow-up to a randomized controlled trial of weight loss in which body composition was analyzed and compared in 78 postmenopausal women before the intervention, immediately after the intervention, and 6 and 12 mo after the intervention.

RESULTS

All body mass and composition variables were lower immediately after weight loss than at baseline (all P < 0.05). More fat than lean mass was lost with weight loss, which resulted in body-composition changes favoring a lower percentage of body fat and a higher lean-to-fat mass ratio (P < 0.001). Considerable interindividual variability in weight regain was noted (CV = 1.07). In women who regained ≥2 kg body weight, a decreasing trend in the lean-to-fat mass ratio was observed, which indicated greater fat mass accretion than lean mass accretion (P < 0.001). Specifically, for every 1 kg fat lost during the weight-loss intervention, 0.26 kg lean tissue was lost; for every 1 kg fat regained over the following year, only 0.12 kg lean tissue was regained.

CONCLUSIONS

Although not all postmenopausal women who intentionally lose weight will regain it within 1 y, the data suggest that fat mass is regained to a greater degree than is lean mass in those who do experience some weight regain. The health ramifications of our findings remain to be seen.

The impact of training modalities on the clinical benefits of exercise intervention in patients with cardiovascular disease risk or type 2 diabetes mellitus

Exercise training intervention represents an effective means to reduce adipose tissue mass, improve glycaemic control and increase whole-body oxygen uptake capacity (VO(2peak)) in obesity, metabolic syndrome, type 2 diabetes mellitus (T2DM) and heart disease patients. In this manuscript, we review the impact of different exercise training modalities on clinical benefits of prolonged exercise intervention in these patient (sub)populations. By changing training modalities, significantly greater clinical benefits can be obtained. Greater training frequency and longer programme duration is associated with greater reduction in adipose tissue mass in obesity patients. A greater training frequency (up to 2 days/week) and a longer programme duration (up to 38 weeks) seems to be associated with greater improvements in VO(2peak) in heart disease patients. Longer programme duration and addition of resistance-type exercise further improve glycaemic control in T2DM patients. The first line of evidence seems to indicate that high-intensity interval exercise training has a greater impact on VO(2peak) in heart disease patients and insulin sensitivity in subjects with metabolic syndrome, but not on adipose tissue mass in obese subjects. However, it remains unclear whether addition of resistance-type exercise and continuous higher-intensity endurance-type exercise training are accompanied by greater improvements in VO(2peak) in heart disease patients. Furthermore, the impact of training session duration/volume on adipose tissue mass loss and glycaemic control in obesity and T2DM patients, respectively, is currently unknown. The impact of training frequency on glycaemic control remains to be investigated in T2DM patients.

AKT1 G205T genotype influences obesity-related metabolic phenotypes and their responses to aerobic exercise training in older Caucasians

As part of the insulin signalling pathway, Akt influences growth and metabolism. The AKT1 gene G205T (rs1130214) polymorphism has potential functional effects. Thus, we determined whether the G205T polymorphism influences metabolic variables and their responses to aerobic exercise training. Following dietary stabilization, healthy, sedentary, 50- to 75-year-old Caucasian men (n = 51) and women (n = 58) underwent 6 months of aerobic exercise training. Before and after completing the intervention, dual-energy X-ray absorptiometry was used to measure percentage body fat, computed tomography to measure visceral and subcutaneous fat, and oral glucose tolerance testing to measure glucose total area under the curve (AUC), insulin AUC and insulin sensitivity. Taqman assay was used to determine AKT1 G205T genotypes. At baseline, men with the GG genotype (n = 29) had lower maximal oxygen consumption (VO2 max) values (P = 0.026) and higher percentage body fat (P = 0.046), subcutaneous fat (P = 0.021) and insulin AUC (P = 0.003) values than T allele carriers (n = 22). Despite their rather disadvantageous starting values, men with the GG genotype seemed to respond to exercise training more robustly than men with the T allele, highlighted by significantly greater fold change improvements in insulin AUC (P = 0.012) and glucose AUC (P = 0.035). Although the GG group also significantly improved VO2 max with training, the change in VO2 max was not as great as that of the T allele carriers (P = 0.037). In contrast, after accounting for hormone replacement therapy use, none of the variables differed in the women at baseline. As a result of exercise training, women with the T allele (n = 20) had greater fold change improvements in fasting glucose (P = 0.011), glucose AUC (P = 0.017) and insulin sensitivity (P = 0.044) than GG genotype women (n = 38). Our results suggest that the AKT1 G205T polymorphism influences metabolic variables and their responses to aerobic exercise training in older, previously sedentary individuals.

Endurance exercise training effects on body fatness, VO2max, HDL-C subfractions, and glucose tolerance are influenced by a PLIN haplotype in older Caucasians

Perilipins are lipid droplet-coating proteins that regulate intracellular lipolysis in adipocytes. A haplotype of two perilipin gene (PLIN) single nucleotide polymorphisms, 13041A>G and 14995A>T, has been previously associated with obesity risk. Furthermore, the available data indicate that this association may be modified by sex. We hypothesized that this haplotype would associate with body fatness, aerobic fitness, and a number of cardiovascular (CV) risk factor phenotypes before and after a 6-mo endurance exercise training program in sedentary older Caucasians. The major haplotype group (13041A/14995A; n = 57) had significantly lower body mass index (BMI) and body fatness compared with noncarriers of the AA haplotype (n = 44) before the training intervention. Training improved body composition in both groups, but fatness remained higher in noncarriers than AA carriers after training. This fat retention in noncarriers blunted their maximal oxygen uptake (Vo(2 max)) adaptation to training. Female noncarriers had substantially higher concentrations of several conventionally and NMR-measured HDL-C subfractions than male noncarriers before and after training, but only minimal differences were found between the sexes in the AA haplotype group. Haplotype group differences in baseline and after-training responses to an oral glucose tolerance test (OGTT) also differed by sex, as noncarrier men had the highest baseline area under the insulin curve (insulin AUC), but were the only group to significantly improve insulin AUC with training. The insulin sensitivity index and plasma glucose responses to the OGTT were more favorable in AA carriers than noncarriers before and after training. Overall, our findings suggest that PLIN variation explains some of the interindividual differences in the response of obesity and CV phenotypes to exercise training. Furthermore, these data contribute to the growing understanding of PLIN as a candidate gene for human obesity and the cardiometabolic consequences of excess adiposity.

Oxidative stress levels are reduced in postmenopausal women with exercise training regardless of hormone replacement therapy status

This study investigated whether postmenopausal women on HRT would experience a greater reduction in oxidative stress after 24 weeks of aerobic exercise training compared to postmenopausal women not on HRT. Plasma thiobarbituric acid reactive substances (TBARS), an indicator of oxidative stress, was measured in 48 previously sedentary postmenopausal women on HRT (n = 21) and not on HRT (n = 27) before and after 24 weeks of aerobic exercise training. Baseline levels of TBARS differed significantly between groups after controlling for age, BMI, and fasting blood glucose (P = 0.03). There was a significant reduction in TBARS after 24 weeks of training in the overall group. When analyzed separately, both postmenopausal women on HRT and those not on HRT had a significant reduction in TBARS; however, there was no significant difference between groups (-0.71 +/- 0.14 nmol/ml in non-HRT users vs. -0.50 +/- 0.16 nmol/ml in HRT users; P = 0.33) even after controlling for age, BMI, and baseline levels of TBARS. Our results showed that aerobic exercise training significantly decreased oxidative stress in postmenopausal women; however, both HRT users and non-HRT users benefited equally.

Correlation between the rate of weight loss and changes in body composition in obese postmenopausal women after 5 weeks: a pilot study

Approximately 25% of weight lost during restrictive diets (without exercise) is lean body mass (LBM). No study has yet investigated the impact of the rate of weight loss (RWL) on LBM and fat mass (FM). The purpose of this study was to investigate the relationships between the RWL and body composition in older obese women. Twenty obese postmenopausal women aged between 51 and 74 years enrolled in a 5 week dietary weight loss intervention. Subjects were characterized according to their RWL (low RWL < 0.74 kg·week–1 (n = 9) vs. high RWL ≥ 0.74 kg·week–1 (n = 11)). Total and trunk FM and LBM (by dual-energy X-ray absorptiometry) were measured before and after weight loss. A significant correlation was observed between the RWL (kg·week–1) and changes in LBM (kg·week–1) (r = 0.75; p = 0.0002). However, no association was observed with changes in FM (kg·week–1) (r = 0.40; p = 0.08). Both groups showed a similar decrease in FM (low RWL, –2.7 ± 0.9 kg,; high RWL, –3.2 ± 0.8 kg; p = 0.38), whereas losses in LBM were significantly higher in the high RWL than in the low RWL group (–1.6 ± 1.2 kg vs. –0.4 ± 1.1 kg; p = 0.05). An RWL > 0.74 kg·week–1 was associated with a greater loss of LBM, but had no extra benefits on FM after a 5 week weight loss program. Current guidelines, which recommend RWL up to 0.91 kg·week–1, might not be optimal to prevent decreases in LBM in postmenopausal women when no exercise is added.

Exercise training-induced changes in coagulation factors in older adults

The coagulation cascade plays a critical role in the development of cardiovascular disease (CVD). Elevated plasma prothrombin fragment 1 + 2 (F1 + 2) and factor VIII antigen (FVIII:Ag) levels have been associated with a hypercoagulable state, enhancing the risk for vascular thrombotic events. Aerobic training is known to reduce CVD risk, and an improved coagulation profile may contribute to this reduction.

PURPOSE

To analyze the effect of 6 months of standardized aerobic exercise training on resting F1 + 2 and FVIII:Ag levels in men and postmenopausal women aged 50-75 while accounting for several possibly confounding factors.

MATERIALS AND METHODS

Sedentary men (N=16) and women (N=31) underwent supervised aerobic training 3 d x wk(-1) for 6 months while maintaining the American Heart Association step 1 diet. Baseline and final testing included measurement of F1 + 2, FVIII:Ag, plasma lipoprotein-lipid levels, body composition, and VO2max.

RESULTS

When adjusted for baseline values and changes in diastolic blood pressure with training, F1 + 2 was found to decrease significantly with exercise training from 1.493 +/- 0.058 to 1.422 +/- 0.059 nM (P=0.014). FVIII:Ag levels were found to increase significantly with training when adjusted for baseline values, from 152.5 +/- 6.7% of standard at baseline to 156.0 +/- 6.1% of standard at final testing (P=0.005). Training-induced changes in coagulation markers were independent of changes in blood lipids, aerobic capacity, and body composition.

CONCLUSIONS

: These results indicate that endurance training has a significant impact on the coagulation cascade, reducing coagulation activity in the common pathway and thrombin formation at rest while increasing the activation potential of the intrinsic pathway.

Endurance exercise training raises high-density lipoprotein cholesterol and lowers small low-density lipoprotein and very low-density lipoprotein independent of body fat phenotypes in older men and women

Endurance exercise training improves plasma lipoprotein and lipid profiles and reduces cardiovascular disease risk. However, the effect of endurance exercise training, independent of diet and body fat phenotypes, on plasma lipoprotein subfraction particle concentration, size, and composition as measured by nuclear magnetic resonance (NMR) spectroscopy is not known. We hypothesized that 24 weeks of endurance exercise training would independently improve plasma lipoprotein and lipid profiles as assessed by both conventional and novel NMR measurement techniques. One hundred sedentary, healthy 50- to 75-year-olds following a standardized diet were studied before and after 24 weeks of aerobic exercise training. Lipoprotein and lipid analyses, using both conventional and NMR measures, were performed at baseline and after 24 weeks of exercise training. Relative and absolute maximum oxygen consumption increased 15% with exercise training. Most lipoprotein and lipid measures improved with 24 weeks of endurance exercise training, and these changes were consistently independent of baseline body fat and body fat changes with training. For example, with exercise training, total cholesterol, triglycerides, and low-density lipoprotein cholesterol (LDL-C) decreased significantly (2.1+/-1.8 mg/dL, P=.001; -17+/-3.5 mg/dL, P<.0001; and -0.7+/-1.7 mg/dL, P<.0001, respectively), and high-density lipoprotein cholesterol subfractions (HDL3-C and HDL2-C) increased significantly (1.9+/-0.5 mg/dL, P=.01, and 1.2+/-0.3 mg/dL, P=.02, respectively). Particle concentrations decreased significantly for large and small very low-density lipoprotein particles (-0.7+/-0.4 nmol/L, P<.0001, and -1.1+/-1.7 nmol/L, P<.0001, respectively), total, medium, and very small LDL particles (-100+/-26 nmol/L, P=.01; -26+/-7.0 nmol/L, P=.004; and -103+/-27 nmol/L, P=.02, respectively), and small HDL particles (-0.03+/-0.4 micromol/L, P=.007). Mean very low-density lipoprotein particle size also decreased significantly (-1.7+/-0.9 nm, P<.0001) and mean HDL particle size increased significantly with exercise training (0.1+/-0.0 nm, P=.04). These results show that 24 weeks of endurance exercise training induced favorable changes in plasma lipoprotein and lipid profiles independent of diet and baseline or change in body fat.

FABP2 Ala54Thr genotype is associated with glucoregulatory function and lipid oxidation after a high-fat meal in sedentary nondiabetic men and women

BACKGROUND

A common functional missense mutation [Ala54Thr of the fatty acid-binding protein 2 gene (FABP2)] has previously been studied for associations with glucoregulation, postprandial lipemia, and lipid oxidation rates. However, most of those studies have not accounted for the interactive and potentially confounding effects of habitual physical activity and diet.

OBJECTIVE

We tested the hypothesis that, in sedentary nondiabetic subjects following a low-fat diet, Thr54 FABP2 carriers have lower glucoregulatory function, greater postprandial lipemia, and greater lipid oxidation rates than do their Ala54 FABP2-homozygous counterparts.

DESIGN

Men and women (n = 122) aged 50-75 y who were following a low-fat diet were genotyped and underwent oral-glucose-tolerance tests. A subgroup (n = 36) also underwent postprandial lipemia tests with lipid oxidation rate measurements.

RESULTS

Thr54 carriers were less likely to have normal glucose tolerance (P = 0.05) and had higher fasting glucose concentrations (P = 0.003) than did Ala54 homozygotes. In Thr54 carriers, the insulin sensitivity index was lower (P = 0.02), and the fasting insulin and the oral-glucose-tolerance test insulin area under the curve were higher (P = 0.05 and 0.03, respectively) than in Ala54 homozygotes. FABP2 genotype was not associated with fasting or postprandial lipemia test triacylglycerol or free fatty acids (P > or = 0.22 for all), but postprandial lipid oxidation rates were higher (P = 0.01), which suggests that fat absorption is higher in Thr54 carriers than in Ala54 homozygotes.

CONCLUSIONS

In sedentary nondiabetic persons following a low-fat diet, FABP2 Thr54 carriers have lower glucose tolerance and lower insulin action than do Ala54-homozygous persons. Furthermore, FABP Thr54 carriers have higher lipid oxidation rates, which may be the mechanism of glucoregulatory dysfunction.

Obesity in older adults: technical review and position statement of the American Society for Nutrition and NAASO, The Obesity Society

Obesity causes serious medical complications and impairs quality of life. Moreover, in older persons, obesity can exacerbate the age-related decline in physical function and lead to frailty. However, appropriate treatment for obesity in older persons is controversial because of the reduction in relative health risks associated with increasing body mass index and the concern that weight loss could have potential harmful effects in the older population. This joint position statement from the American Society for Nutrition and the NAASO, The Obesity Society reviews the clinical issues related to obesity in older persons and provides health professionals with appropriate weight-management guidelines for obese older patients. The current data show that weight-loss therapy improves physical function, quality of life, and the medical complications associated with obesity in older persons. Therefore, weight-loss therapy that minimizes muscle and bone losses is recommended for older persons who are obese and who have functional impairments or medical complications that can benefit from weight loss.

Gender-related changes in body composition, muscle strength and power output after a short-term multidisciplinary weight loss intervention in morbid obesity

Obese men and women have notably different body composition, which contributes to a different functional motor impairment, but it is unknown whether they respond differently to the same intervention for body weight (BW) reduction and motor capability improvement. The aim of this investigation was to compare changes in body composition, strength production and power output observed in severely obese men and women after a BW reduction intervention, and to test the hypothesis that changes in body composition may be related to changes in motor functionality. Ninety-five obese men and women of the same age (29.3 +/- 7.0 SD yr) and body mass index (41.2 +/- 4.4 kg/m2) participated in a short-term (3 week) mass reduction program (5 days/week) entailing exercise (aerobic and strength training) and energy-restricted diet. BW and body composition, maximum voluntary total isotonic strength (ST), and maximum leg power output (W) were evaluated before and after the program. After the intervention, BW decreased significantly in both men and women, but males lost a significantly higher amount of their initial BW than females (5.12 +/- 0.91 vs 4.27 +/- 1.42%, p<0.01). In men the BW loss was composed by a similar amount of fat mass (FM) and fat-free mass (FFM), whereas women lost FM almost entirely. Both men and women significantly improved ST after the intervention, but no difference in improvement was detected between genders, while W increased significantly in females (p<0.001), and no change was detected in males, although W per unit BW and FFM increased significantly in both genders (p<0.05-0.001). In spite of the positive correlation of ST and W with FFM (p<0.001), there was no detectable relation between the changes in body composition and those in motor performance, the improvement in ST and W being better attributable to factors other than muscle mass change. The present diet/exercise intervention induced significant effects on BW changes and composition as well as on ST and W, with a different impact in males and females.

Endurance training-induced changes in the insulin response to oral glucose are associated with the peroxisome proliferator-activated receptor-gamma2 Pro12Ala genotype in men but not in women

The present study sought to investigate, in sedentary men and women, (a) whether a common functional gene variant (peroxisome proliferator-activated receptor-gamma2 [PPARgamma2] Pro12Ala) predicts insulin action and (b) whether improvements in insulin action in response to endurance exercise training are associated with PPARgamma2 Pro12Ala. Sedentary, 50- to 75-year-old men and women (N = 73) were genotyped and underwent oral glucose tolerance tests (OGTTs) before and after 6 months of endurance training. At baseline, men heterozygous for the Pro12Ala variant had a greater OGTT insulin area under the curve (AUC) as compared with Pro12 homozygous men (P = .009). Endurance training resulted in a significantly greater improvement in insulin AUC in Pro12Ala heterozygous men as compared with Pro12 homozygous men (P = .003) despite no genotype-specific differences with respect to training-induced changes in body weight, body mass index, and percent body fat. No differences between genotype groups were present at baseline or in response to training in women. Training did not alter the OGTT glucose AUC for the group as a whole, and the baseline, final, and change in glucose AUC were not dependent on PPARgamma2 genotype and/or sex. In conclusion, these findings suggest that sedentary men with the PPARgamma2 Pro12Ala variant have lower insulin action on glucose disposal as compared with their counterparts. However, these men are particularly responsive with respect to the magnitude of endurance training-induced improvement in insulin action.

Influence of the interleukin-6 -174 G/C gene polymorphism on exercise training-induced changes in glucose tolerance indexes

A polymorphism in the IL-6 gene, a G-to-C substitution 176 bp upstream of the ATG translation initiation site, has been associated with diabetes prevalence and insulin resistance. Interventions including exercise training are frequently used to modify cardiovascular disease risk factors. Consequently, this project examined associations between the IL-6 -174 genotype and oral glucose tolerance test outcomes in 50- to 75-yr-old sedentary men and postmenopausal women before and after aerobic exercise training. Among the 87 individuals who started the study, 56 were retested after 6 mo of aerobic exercise training. Subject characteristics at baseline did not differ between the IL-6 genotype groups with the exception of fasting glucose, which was higher (P = 0.02, covariates age, gender, and ethnicity) in the CC genotype group. The training-induced change in glucose area under the curve during the oral glucose tolerance test varied between the IL-6 -174 genotype groups (P = 0.05, covariates age, gender, ethnicity, baseline glucose area under the curve, and percent body fat change) with a significant decrease occurring only in the GG genotype group. Insulin outcomes did not differ among the groups at baseline or after training. Training-induced changes in weight, percent body fat, maximal oxygen consumption, fasting glucose, and an insulin sensitivity index also changed similarly among the genotype groups. In conclusion, fasting glucose and the extent to which glucose tolerance changes with exercise training may be influenced by the IL-6 -174 gene polymorphism.

Exercise and aging

There is increasing evidence that the black box we have referred to as"biologic aging" is composed of genetic factors and many types of environmental exposures. Some of the most potentially modifiable elements of this syndrome are those attributable to disuse or insufficient exposure to certain kinds or intensities of physical stressors during the course of the life span. Beneficial adaptations to exercise once thought restricted to genetically endowed master athletes now are seen to occur just as predictably in frail elders with chronic disease, opening the door to vastly improved physical function and associated health benefits. Knowledge of the benefits of physical activity, however well substantiated, may be necessary, but it is not sufficient to change either physician-prescribing habits or the likelihood of adoption and long-term adherence to exercise on the part of patients. Ultimately, the penetration of an exercise prescription to optimize aging into the most inactive cohorts in the community,who have the most to gain from increases in levels of physical activity and fitness, will depend on a combination of clear evidence-based guidelines coupled with health professional training and behavioral programs tailored to age-specific barriers and motivational factors.

Plasma nitrate/nitrite response to an oral glucose load and the effect of endurance training

To assess the role of circulating nitric oxide (NO) production in glucose homeostasis, plasma nitrate/nitrite (NO(x)) was assessed during oral glucose tolerance tests (OGTTs) on 64 sedentary subjects and in a subset 40 subjects before and after 6 months of endurance exercise training. NO(x) decreased with the oral glucose load (P </=.001 for linear and quadratic effects). OGTT NO(x) response indices (NO(x) response area (NO(x) AREA), change in NO(x) from baseline to the minimum (DeltaNO(x)), and NO(x) time-to-minimum) were not associated with OGTT insulin or glucose areas under the curve (AUCs) or with insulin sensitivity index (ISI). Training did not alter NO(x) AREA, or DeltaNO(x), however, NO(x) time-to-minimum occurred later after training (P =.038). Training-induced insulin AUC and ISI changes were not associated with OGTT NO(x) index changes; however, glucose total AUC changes were associated with changes in NO(x) AREA (r =.42, P =.007) and DeltaNO(x) (r =.37, P =.019). In conclusion, these data suggest that circulating NO production is not involved in glycemic control after an oral glucose load in sedentary adults. In response to endurance training, however, it appears that the time required to reach minimum NO(x) levels after a glucose load is greater after training. Furthermore, although the magnitude of NO(x) response (as indicated by NO(x) AREA and DeltaNO(x)) to an oral glucose load does not appear to change with training for all individuals, individual training-induced changes in the NO(x) response magnitude are partly explained by training-induced changes in OGTT glucose responses.

High-density lipoprotein-cholesterol, its subfractions, and responses to exercise training are dependent on endothelial lipase genotype

Plasma high-density lipoprotein cholesterol (HDL-C) levels are an important independent risk factor for cardiovascular disease (CVD) that can be modified through exercise training. However, levels of HDL-C and its subfractions and their response to standardized exercise training are highly variable among individuals. Such variability suggests that levels of HDL-C, its subfractions, and their response to exercise training may be influenced by genetic variation and the interaction of that genetic variation with physical activity. The endothelial lipase gene (LIPG) may influence HDL-C metabolism and has several recently identified genetic variants. We hypothesized that the LIPG Thr111Ile polymorphism would be associated with variation in HDL-C levels and its subfractions and their response to exercise training. Eighty-three sedentary, healthy 50- to 75-year-old subjects were weight-maintained on an American Heart Association Step 1 Diet and then studied before and after aerobic exercise training. Sample size varied according to outcome measure as complete data was not available for all subjects. Initial age, body composition, and maximum oxygen consumption (V02max) did not differ between LIPG genotype groups (CC, n=41 to 44; CT/TT, n=37 to 39). Initial total cholesterol, low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) levels were not significantly different between groups. The CT/TT group had lower initial HDL(2NMR)-C (12 +/- 1.0 v 17 +/- 1.1 mg/dL; P =.002) and integrated HDL(1,2NMR)-C (13 +/- 1.0 v 18 +/- 1.1 mg/dL; P=.002) levels and somewhat higher initial levels of integrated HDL(3,4,5)-C (31 +/- 2.2 v 25 +/- 2.3 mg/dL; P=.06). With exercise training, Vo2max increased, and body weight, total body fat, and visceral adipose tissue decreased similarly in both groups. With training, HDL-C levels increased twice as much (4.4 +/- 0.8 v 1.9 +/- 0.9 mg/dL; P=.04), HDL3-C levels increased almost 2-fold greater (3.8 +/- 0.7 v 2.2 +/- 0.6 mg/dL; P=.07), and HDL(5NMR)-C levels increased more than 4 times as much (2.2 +/- 0.8 v 0.5 +/- 0.6 mg/dL; P=.08) in the CC compared to the CT/TT group. We conclude that the LIPG genotype is associated with interindividual variability in HDL-C and its subfractions and their response to exercise training.

Benefits of exercise and dietary measures to optimize shifts in body composition with age

Ageing is associated with changes in body composition, including an increase and redistribution of adipose tissue and a decrease in muscle and bone mass, beginning as early as the fourth decade of life. These changes have significant implications for the health and functioning of the individual because of their associations with chronic disease expression and severity, as well as geriatric syndromes such as mobility impairment, falls, frailty and functional decline. Therefore, understanding the preventive and therapeutic options for optimizing body composition in old age is central to the care of patients in mid-life and beyond. Pharmacological interventions are currently available for maintaining or improving bone mass, and much current interest is focused on anabolic agents that will preserve or restore muscle mass, as well as those that can potentially limit adipose tissue deposition. However, in this brief review, non-pharmacological modulation of body composition through appropriate dietary intake and physical activity patterns, will be discussed. There is sufficient evidence currently to suggest that a substantial portion of what have been considered 'age-related' changes in muscle, fat and bone are in fact related either to excess energy consumption, decreased energy expenditure in physical activity, or both factors in combination. In addition, selective underconsumption of certain macro- or micronutrients contributes to losses of muscle and bone mass. Each of the three compartments will be considered in turn, with recommendations for optimizing the size of these body tissue stores in early adulthood, and minimizing undesirable changes typically seen in middle and old age.

Patient management after LAP-BAND placement

Severe obesity is a chronic disease requiring continuing care. Optimal outcomes of laparoscopic adjustable gastric banding using the LAP-BAND (INAMED Health, Santa Barbara, CA) depend on accurate placement of the band and excellent postplacement care, which requires a long-term commitment from both the patient and the bariatric surgical team. Adjustability is a key feature of the LAP-BAND system, and knowing when and how much to adjust requires careful judgment. Two methods of approaching the art of adjustment are described: the office adjustment and the radiologic adjustment. A properly placed and adjusted band produces prolonged satiety after a small meal, facilitating a major reduction in dietary intake leading to weight loss. Healthy food choices, increased activity and exercise, and the behavioral changes necessary to achieve these are essential elements of all weight loss programs. The LAP-BAND program is no exception. Follow-up requires monitoring of the comorbidities of obesity and metabolic and nutritional status. Communication and collaboration with the patient's primary care provider are important. All of the elements above are necessary to provide the comprehensive care that contributes to optimal patient outcomes.

Sexual dimorphism in the energy content of weight change

BACKGROUND

The energy content of weight change is assumed to be sex- and age-neutral at 3,500 kcal/pound or 32.2 MJ/kg.

OBJECTIVES

As sexual dimorphism in body composition generally exists in mammals, the primary hypothesis advanced and tested was that the energy content of weight change differs between men and women.

DESIGN

The energy content of 129 adult men and 287 women was measured by neutron activation analysis. Cross-sectional energy content prediction models were developed and then evaluated in two longitudinal samples: one that used the same methods in 26 obese women losing weight; and the other a compilation of 18 previously reported weight change-body composition studies.

RESULTS

Multiple regression modeling identified weight, sex, age and height as total energy content predictor variables with significant sex x weight (P<0.001) and age x weight (P<0.001) interactions; total model r(2) and s.e.e. were 0.89 and 107.3 MJ, respectively. The model's predictive value was supported in both longitudinal evaluation samples. Model calculations using characteristics of representative adults gaining or losing weight suggested that the energy content of weight change in women (approximately 30.1-32.2 MJ/kg) is near to the classical value of 32.2 MJ/kg and that in men the value is substantially lower, approximately 21.8-23.8 MJ/kg. The predicted energy content of weight change increases by about 10% in older (age approximately 70 y) vs younger (approximately 35 y) men and women.

CONCLUSIONS

Sexual dimorphism and age-dependency appears to exist in the estimated energy content of weight change and these observations have important clinical and research implications.

Anorexia, body composition, and ageing

Over the lifespan there is a decline in food intake. This has been termed the physiological anorexia of aging. It has many causes, including alterations in the gastrointestinal satiating system, the effect of elevated leptin levels, especially in men, and a variety of changes in central nervous system neurotransmitters. Beyond the age of 70 years body mass declines. This includes both loss of adipose tissue and muscle mass. The loss of muscle mass in older individuals is termed sarcopenia. There is increasing evidence that this is caused, in men, partly by the decline in testosterone. Illness results in an increase of cytokines that produce both anorexia and cause protein wasting. Many of the causes of cachexia in older individuals are treatable. Depression is the most common cause of weight loss in older individuals. Dieting in older individuals is associated with a loss of skeletal tissue as well as fat mass. This can place older individuals at risk of becoming the 'fat frail'.

Weight loss in postmenopausal obesity: no adverse alterations in body composition and protein metabolism

We sought to determine if decrements in the mass of fat-free body mass (FFM) and other lean tissue compartments, and related changes in protein metabolism, are appropriate for weight loss in obese older women. Subjects were 14 healthy weight-stable obese (BMI > or =30 kg/m(2)) postmenopausal women >55 yr who participated in a 16-wk, 1, 200 kcal/day nutritionally complete diet. Measures at baseline and 16 wk included FFM and appendicular lean soft tissue (LST) by dual-energy X-ray absorptiometry; body cell mass (BCM) by (40)K whole body counting; total body water (TBW) by tritium dilution; skeletal muscle (SM) by whole body MRI; and fasting whole body protein metabolism through L-[1-(13)C]leucine kinetics. Mean weight loss (+/-SD) was 9.6+/-3.0 kg (P<0.0001) or 10.7% of initial body weight. FFM decreased by 2.1+/-2.6 kg (P = 0.006), or 19.5% of weight loss, and did not differ from that reported (2.3+/-0.7 kg). Relative losses of SM, LST, TBW, and BCM were consistent with reductions in body weight and FFM. Changes in [(13)C]leucine flux, oxidation, and synthesis rates were not significant. Follow-up of 11 subjects at 23.7 +/-5.7 mo showed body weight and fat mass to be below baseline values; FFM was nonsignificantly reduced. Weight loss was accompanied by body composition and protein kinetic changes that appear appropriate for the magnitude of body mass change, thus failing to support the concern that diet-induced weight loss in obese postmenopausal women produces disproportionate LST losses.

The role of exercise in the treatment of obesity

The prevalence of obesity in the USA has increased dramatically in the past decade. This foreshadows an increase in the rates of morbidity and mortality from obesity-related diseases and increases in the number of individuals undergoing weight-loss therapy. Although exercise has long been recommended for inclusion in such therapy, the present review has found that it has had little or no effect on weight loss per se when the exercise is limited to the typically prescribed 3-5 h/wk of moderate or vigorous activity. However, further review has shown that exercise helps to preserve and at times even increase fat-free mass during weight loss. At the same time, fat loss is generally increased. Neither type nor amount of exercise appears to have much effect during treatment, with the possible exception of resistance training, which is associated with the best outcome for fat-free mass. The most important role of exercise, however, is in the maintenance of the weight loss. In this respect, the volume of exercise seems to be important because several lines of evidence have indicated that exercise must expend roughly 2500 kcal/wk to maintain weight loss. Studies of weight maintenance, however, have generally not included randomized controls; thus, further research is required to solidify these conclusions.

Physical activity in the treatment of the adulthood overweight and obesity: current evidence and research issues

PURPOSE

The purpose of this paper is to review the evidence on the role of physical activity in the treatment of adult overweight and obesity. Three specific questions are addressed: (1) Does exercise alone produce weight loss? (2) Does exercise in combination with diet produce greater weight loss than diet only? and (3) Does exercise in combination with diet produce better maintenance of weight loss than diet alone?

METHODS

The literature initially identified by the Expert Panel on Clinical Guidelines for the Treatment of Obesity, three key meta analyses, and additional literature searches were used to identify randomized trials related to the three aforementioned topics. These articles were reviewed and tabulated.

RESULTS

Six of 10 randomized studies found significantly greater weight loss in exercise alone versus no treatment controls. The magnitude of the effect averaged 1-2 kg. Only 2 of 13 studies found significant differences in initial weight loss for diet plus exercise versus diet only, although almost all studies pointed in this direction. Six studies were identified with maintenance periods of at least 1 yr. In two of the six there were significant long term differences favoring diet plus exercise, but in every study considered the direction of the difference favored diet plus exercise. Other strong evidence showing benefits of exercise for long-term weight loss comes from correlational analyses which consistently find that those individuals who report the greatest exercise have the best maintenance of weight loss.

CONCLUSIONS

Randomized trials consistently show benefits of exercise for weight loss, but the effects are often modest. This may result from small sample sizes, short study duration, and poor adherence to the exercise prescriptions. To better define the doses and types of exercise that will promote long-term weight loss, it is necessary to develop better ways to measure exercise and promote adherence to exercise.

Influence of exercise training on physiological and performance changes with weight loss in men

PURPOSE

The purpose of this study was to examine the physiological effects of a weight-loss dietary regimen with or without exercise.

METHODS

Thirty-five overweight men were matched and randomly placed into either a control group (C; N = 6) or one of three dietary groups; a diet-only group (D; N = 8), a diet group that performed aerobic exercise three times per week (DE; N = 11); and a diet group that performed both aerobic and strength training three times per week (DES; N = 10).

RESULTS

After 12 wk, D, DE, and DES demonstrated a similar and significant (P < or = 0.05) reduction in body mass (-9.64, -8.99, and -9.90 kg, respectively) with fat mass comprising 69, 78, and 97% of the total loss in body mass, respectively. The diet-only group also demonstrated a significant reduction in fat-free mass. Maximum strength, as determined by 1-RM testing in the bench press and squat exercise was significantly increased for DES in both the bench press (+19.6%) and squat exercise (+32.6%). Absolute peak O2 consumption was significantly elevated in DE (+24.8%) and DES (+15.4%). There were no differences in performance during a 30-s Wingate test for the DE and DES, whereas D demonstrated a significant decline in peak and mean power output. Resting metabolic rate (RMR) (kcal x d(-1)) was not significantly different for any of the groups except for the DE group. There were no significant changes in basal concentrations of serum glucose, BUN, cortisol, testosterone, and high density lipoprotein (HDL) cholesterol for any of the groups. Serum total cholesterol and low density lipoprotein (LDL) cholesterol were significantly decreased for all dietary groups. Serum triglycerides were significantly reduced for D and DES at week 6 and remained lower at week 12 for D, while triglycerides returned to baseline values for DES.

CONCLUSIONS

These data indicate that a weight-loss dietary regimen in conjunction with aerobic and resistance exercise prevents the normal decline in fat-free mass and muscular power and augments body composition, maximal strength, and maximum oxygen consumption compared with weight-loss induced by diet alone.

Weight loss counseling by health care providers

OBJECTIVES

This study explores the pattern of weight loss counseling by health care providers in Connecticut and the associated weight loss efforts by patients.

METHODS

Data from the 1994 Connecticut Behavioral Risk Factor Surveillance System survey were analyzed to determine (1) the frequency of weight management counseling by health care providers of overweight adults with and without additional cardiovascular risk factors and (2) the current weight loss practices of overweight subjects.

RESULTS

Only 29% of all overweight respondents and fewer than half with additional cardiovascular risk factors, reported that they had been counseled to lose weight.

CONCLUSIONS

The findings suggest a need for more counseling of overweight persons, especially those with cardiovascular disease risk factors.

Combined exercise and dietary intervention to optimize body composition in aging

Concomitant losses of skeletal muscle and bone mass along with gradual accretion of adipose tissue typify usual human aging. Recent investigations have attempted to modify these processes with various combinations of dietary and exercise intervention in older adults. Complete nutritional supplements given with weight-lifting exercise have been shown to augment muscle and fat gains in healthy older men, but have merely suppressed habitual dietary intake when administered to frail sedentary elders, and have not altered body composition responses to strength training in this population. Protein supplementation at twice the RDA does not improve skeletal muscle function or increase muscle mass in healthy elderly weight lifters compared to those on a normal diet. Calcium supplementation during one year of aerobic training has an independent beneficial effect on cortical bone density at the femoral neck in postmenopausal women, whereas the exercise is associated with trabecular bone increases in the lumbar vertebrae. Hypocaloric dieting, with or without aerobic exercise, results in losses of weight, fat and lean mass in obese elderly men and women. By contrast, resistance training during hypocaloric dieting augments lean mass while further reducing fat mass. Low protein, isoenergetic diets result in muscle atrophy in older women. Current studies will determine the ability of resistance training to offset these catabolic effects on skeletal muscles of a low-protein (0.6 g/kg/day) diet prescribed for elderly with chronic renal failure. More long-term studies of efficacy and feasibility of diet and exercise combinations are needed in the aged to optimize the potential for healthful shifts in body composition.

Physiological adaptations to a weight-loss dietary regimen and exercise programs in women

Thirty-one women (mean age 35.4 +/- 8.5 yr) who were overweight were matched and randomly placed into either a control group (Con; n = 6), a diet-only group (D; n = 8), a diet+aerobic endurance exercise training group (DE; n = 9), or a diet+aerobic endurance exercise training+strength training group (DES; n = 8). After 12 wk, the three dietary groups demonstrated a significant (P </= 0.05) reduction in body mass, %body fat, and fat mass. No differences were observed in the magnitude of loss among groups, in fat-free mass, or in resting metabolic rate. The DE and DES groups increased maximal oxygen consumption, and the DES group demonstrated increases in maximal strength. Weight loss resulted in a similar reduction in total serum cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol among dietary groups. These data indicate that weight loss during moderate caloric restriction is not altered by inclusion of aerobic or aerobic+resistance exercise, but diet in conjunction with training can induce remarkable adaptations in aerobic capacity and muscular strength despite significant reductions in body mass.