Body composition and energy expenditure after weight loss following bariatric surgery

OBJECTIVES: To assess the effectiveness of biliopancreatic diversion (BPD) in the treatment of morbid obesity and to evaluate how the procedure affects body weight. SUBJECTS: Fourteen morbidly obese subjects studied before and 30 months after BPD and fifteen healthy volunteers matched for age, sex and height (controls). METHODS: Comparison of the following parameters were made in the study groups before surgery and 30 months after BPD and with those of the controls group: fat mass, fat-free mass, non-protein substrate oxidation, basal metabolic rate, plasma glucose, insulin and free fatty acid concentrations. RESULTS: Obese subjects lost 60.38+/-10.71 kg of weight during 18 months following surgery and then remained stable for another 12 months, when this study was performed. Weight loss was substantially due to a loss of fat mass (FM: 60.13+/-13.01 kg before and 19.02+/-8.61 kg after BPD; p<0.001). FM were not statistically different between post-obese subjects and controls; however, post-obese patients retained significantly more fat free mass (FFM) than controls. Subsequently, basal metabolic rates of post-obese subjects were higher than those of the control group (p<0.05). Fasting non-protein respiratory quotient (npRQ) was significantly lower before BPD than 30 months after the surgery (0.798+/-0.04 vs. 0.90+/-0.048, p<0.001), suggesting that, while obese, patients oxidized more lipids than carbohydrates. Moreover, fasting and two-hour plasma glucose and insulin concentrations decreased significantly after BPD to values comparable to those of the control group. CONCLUSION: Weight loss in obese patients after BPD is mainly due to lipid malabsorption, but increased energy expenditure associated with retaining a high FFM in physically active post-obese subjects may also play a role, enabling them to maintain long-term reduced body weights.     

Factors influencing energy intake and body weight loss after gastric bypass

OBJECTIVE: The gastric bypass-induced quantitative and qualitative modifications of energy intake (En In, kcal/day) and their impact on body weight (bw) loss were evaluated. The factors influencing energy intake and body weight loss were also investigated. DESIGN: Longitudinal study. SETTING: University Hospital of Geneva. SUBJECTS: Fifty obese women undergoing a Roux-en-Y gastric bypass. RESULTS: The reduction of EnIn was significantly related to bw loss expressed either in kg or as percentage correction of excess bw (P<0.01 for both), whereas the post-operative modifications of diet composition did not play a role. Age and initial bw significantly influenced bw loss (P<0.0001 and P<0.001, respectively), as shown by multiple regression analysis. Patients were divided into four sub-groups according to their age (under or over 35 y) and initial bw (under or over 120 kg). ANOVA showed that under 35-y-old subjects reduced their EnIn significantly more than their older counterparts having similar bw (P<0.02 and P<0.05); consequently, bw loss, expressed in kg, was significantly (P<0.0001 and P<0.0005) larger in younger patients. Subjects with an initial bw over 120 kg lost significantly (P<0.001 and P<0.02) more weight as compared to patients with a smaller degree of obesity (under 120 kg) and similar age. CONCLUSIONS: Gastric bypass-induced body weight loss is mainly due to the reduction of EnIn, whereas the qualitative modifications of the diet do not play a role. Younger subjects have a greater capacity to reduce EnIn and, therefore, lose more weight. Pre-operative high degree of obesity leads to a larger weight reduction, probably because of a greater energy deficit.     

Gynecologic-obstetric changes after loss of massive excess weight following bariatric surgery

A clinical study was undertaken to assess gynecologic-obstetric changes in morbidly obese women who lost greater than or equal to 50% of their excess weight with bariatric surgery. The 138 females (109 of reproductive age), age 35 +/- 9 SD yr, weighed 124 +/- 23 kg before surgery and 79 +/- 13 kg after weight loss had stabilized. Menstrual irregularities were present in 40.4% of premenopausal patients preoperatively; after massive weight loss, cycles were abnormal in 4.6% (p less than 0.001). Infertility problems were present preoperatively in 29.3% Of these, nine tried to conceive after weight loss and were successful. During past pregnancies, medical complications were frequent (hypertension 26.7%, pre-eclampsia 12.8%, diabetes 7.0%, and deep vein thrombosis 7.0%). After weight-loss stabilization, these obstetric complications did not occur. Incidence of urinary stress incontinence decreased from 61.2% to 11.6% (p less than 0.001). Gynecologic-obstetric changes tended to normalize after loss of massive body weight.     

Failure of preoperative resting energy expenditure in predicting weight loss after gastroplasty

OBJECTIVE: To evaluate the predictive efficacy of preoperative resting energy expenditure (REE) on weight loss after vertical banded gastroplasty (VBG). When subjected to a gastric restriction procedure of similar extent, the patients with higher energy expenditure should experience a greater negative energy balance than those with lower-energy expenditure, and thus, lose more weight, thereby making REE a reliable predictor of weight loss after VBG. RESEARCH METHODS AND PROCEDURES: This was a prospective investigation after VBG, taking into account the relationship between preoperative REE values and the results at 1-year follow-up in terms of weight loss and success of the procedure. The correlations were evaluated by multiple and logistic regression analysis. RESULTS: The weight loss and the outcome at 1 year after VBG seemed to be completely independent of preoperative energy expenditure. DISCUSSION: These findings suggest that, despite gastric restriction, patients may voluntarily adjust their energy intake, and that the weight outcome after VBG is influenced more by behavioral and cognitive variables than by biological or surgical factors.     

Changes of body weight and plasma ghrelin levels after gastric banding and gastric bypass

OBJECTIVE: Ghrelin is an enteric peptide with strong orexigenic and adipogenic effects. Plasma ghrelin levels are decreased in obese subjects but increase after weight loss; this increase is not observed after Roux-en-Y gastric bypass (RYGB). Prospective and comparative data after adjustable silicone gastric banding (ASGB) have not been reported previously. RESEARCH METHODS AND PROCEDURES: Overnight fasting plasma ghrelin concentration was measured in morbidly obese subjects at baseline and 3, 6, 12, and 24 months after ASGB (n = 8) or RYGB (n = 5) and in nonoperated controls (n = 7). RESULTS: After RYGB, body weight (BW) decreased by 29.5 +/- 5.5 kg (mean +/- SE, p < 0.001), whereas plasma ghrelin failed to increase significantly (+167 +/- 119 pg/mL, not significant). In contrast, after ASGB, BW decreased less (by 22.8 +/- 5.9 kg; p < 0.001), and plasma ghrelin significantly increased by 377 +/- 201 pg/mL (p = 0.025). Neither BW nor plasma ghrelin changed in nonoperated controls. Plasma leptin decreased in both operated groups (similarly p < 0.05) but not in nonoperated controls. Plasma growth hormone and insulin-like growth factor 1 were not correlated with changes in plasma ghrelin concentrations. DISCUSSION: Plasma ghrelin levels failed to increase during substantial weight loss after RYGB, but did increase in response to lesser weight loss after ASGB. These findings suggest that the plasma ghrelin response after weight loss is impaired after exclusion of major parts of the stomach and the duodenum (RYGB), and the smaller long-term weight loss after ASGB compared with RYGB may be due, at least in part, to an absent increase in plasma ghrelin after RYGB.     

Changes in body composition during weight loss

Studies based on conditions found in World War II and on the "Minnesota" project show that a reduced intake of energy not only reduces the amount of body fat but also (with the exception of the brain and of bones) all organs are affected to varying degrees. Body water loss is followed by water retention and, during recovery from reduced energy intake, the body fat content increases above pre-diet levels before returning to normal.     

Adjusting energy expenditure for body weight in early infancy

The most appropriate method of expressing energy expenditure relative to body weight was investigated in 50 normal, full-term infants at 6 weeks, 12 weeks and 6 months of age. Regression analysis revealed that the relationship between body weight and energy expenditure at each age could be adjusted for by expressing energy expenditure per kg0.65, per kg0.43 and per kg0.55 body weight at the three age points studied. These powers were not significantly different and a pooled estimate was per kg0.56. This is very close to kg0.5 or the square root of body weight. It is suggested that in studies on energy, metabolism in early infancy the expression of total energy expenditure per kg0.5 body weight should be used as the most appropriate adjustment for removing the influence of body weight upon energy expenditure.     

Improvements in body composition, glucose tolerance, and insulin action induced by increasing energy expenditure or decreasing energy intake

Increases in exercise energy expenditure without compensatory changes in food intake (EX) and restriction of calorie intake (CR) both decrease body weight and fat mass, which, in turn, improve glucoregulatory function. However, EX may provide greater benefits than can be provided through CR. Therefore, our study hypothesis was that weight loss through EX reduces visceral abdominal fat and improves glucoregulation to a greater extent than does similar weight loss through CR. Forty-eight sedentary 50- to 60-y-old men and women, most of whom were overweight, underwent 12 mo of EX, CR, or a healthy lifestyle control period. Body composition was assessed by dual-energy x-ray absorptiometry and by magnetic resonance imaging. Indices of glucoregulatory function were determined by oral glucose tolerance test and were measured > or =48 h after the last exercise bout in the EX group. Body weight, total fat mass, and visceral fat volume decreased similarly in the EX and CR groups but did not change in the HL group. Likewise, insulin sensitivity index and the oral glucose tolerance test glucose and insulin areas under the curve improved similarly in the EX and CR groups and remained unchanged in the HL group. In conclusion, weight losses induced by exercise and by CR are effective means for improving glucose tolerance and insulin action in nonobese, healthy, middle-aged men and women; however, it does not appear that exercise training-induced weight loss results in greater improvements than those that result from CR.     

Resting energy expenditure and body composition following cerebro-vascular accident

The aim of this study was to measure resting energy expenditure (REE) in patients routinely admitted to hospital following a cerebro-vascular accident (CVA). The REE of 15 patients (8 female; 7 male) was measured using indirect calorimetry 24-72 hours after the CVA; 11 patients (7 female; 4 male) were measured again 10-14 days later. Body composition was assessed using skin-fold thickness, near infra-red interactance and bioelectrical impedance techniques. Initial REE in females was 1133 kcal/day (+/-67) and in males 1526 kcal/day (+/-111). There was little or no difference in REE or body composition between the first and second measurements. REE was between 95%-107% of the values predicted by 10 reference tables and equations and up to 118% of that predicted by another. We conclude that the total energy requirements of patients following a stroke are not high, probably because of decreased physical activity and changes in muscular tone subsequent to CVA.     

Physical activity energy expenditure predicts changes in body composition in middle-aged healthy whites: effect modification by age

BACKGROUND: It is unclear whether physical activity energy expenditure (PAEE) predicts changes in body composition. OBJECTIVE: The objective was to describe the independent associations between PAEE and changes in body composition in a population-based cohort. DESIGN: This was a prospective population-based study conducted in 739 (311 men and 428 women) healthy middle-aged (median age: 53.8 y) whites. The median follow-up was 5.6 y. PAEE (MJ/d) was assessed by heart rate monitoring, individually calibrated by using the FLEX heart rate method. Fat mass (FM) and fat-free mass (FFM) were assessed by bioimpedance. RESULTS: Body weight (BW) at follow-up was significantly related to baseline PAEE (P < 0.05) after adjustment for sex, baseline age, FM, FFM, and follow-up time. A significant interaction between PAEE and age (P = 0.023) was observed. After the subjects were stratified (above and below the median for age), BW increased by a mean (+/-SD) of 1.7 +/- 5.9 kg (P < 0.0001) in the younger cohort. In this group, follow-up FM was significantly associated with baseline PAEE (P = 0.036) after adjustment for confounders. In the older cohort, BW did not change between baseline and follow-up. In this group, in contrast with the younger population, follow-up BW, FM, and FFM were all significantly and positively associated with baseline PAEE (P < 0.01 for all). CONCLUSIONS: Baseline PAEE predicts a change in FM in younger adults, who as a group gained weight in this study. In contrast, baseline PAEE in older adults--who were on average weight stable--is associated with a gain in BW, which was explained by an increase in FM and FFM.     

学龄儿童运动能量消耗与人体成分的关系

目的　探讨学龄期儿童运动能量消耗（AEE）与人体成分之间的关系。方法　以上海市杨浦区二联小学三、四年级62名学生为研究对象,使用代谢车测定运动能量消耗,利用生物电阻抗法测定人体成分,包括体质量、体质量指数、体脂率、脂肪含量、去脂体质量、脂肪含量指数、去脂体质量指数、肥胖度和AEE,比较超重肥胖组与非超重肥胖组儿童各指标的差异,并探讨其关系。结果　男生超重肥胖组和非超重肥胖组的运动时间［（9.70±1.91）min 比（10.00±1.97）min;t=0.336,P=0.739］、总AEE［（198.74±53.33）kJ 比 （171.54±41.75）kJ;t=-1.422,P=0.165］、AEE相对值［（0.46±0.09）kJ/(min·kg）比（0.51±0.04）kJ/(min·kg); t=2.043,P=0.051］差异均无统计学意义,超重肥胖组AEE绝对值高于非超重肥胖男生组［（20.06±3.14）kJ/min比（16.93±1.85）kJ/min;t=-2.910,P=0.007］。女生超重肥胖组与非超重肥胖组相比运动时间更短［（7.35±3.05）min 比 （9.98±1.82）min;t=2.509,P=0.027］、AEE相对值更小［（0.41±0.09）kJ/(min·kg）比 （0.51±0.07）kJ/(min·kg）;t=3.244,P=0.003］,但两组总AEE［（129.29±71.13）kJ 比 （161.50±35.38）kJ;t=1.351,P=0.203］、AEE绝对值［（16.82±3.26）kJ/min 比 （16.17±2.00）kJ/min; t=-0.676,P=0.504］差异均无统计学意义。控制年龄和性别因素后,男生AEE绝对值与体质量指数（P=0.015）、肥胖度(P=0.010)、脂肪含量(P=0.047)、去脂体质量(P=0.010）和去脂体质量指数(P=0.003)呈显著正相关,女生AEE绝对值与体成分各指标无相关性。AEE相对值与体质量指数（男：P=0.000,女：P=0.000）、肥胖度（男：P=0.002,女：P=0.000）、体脂率（男：P=0.000,女：P=0.001）、脂肪含量（男：P=0.000,女：P=0.000）、去脂体质量（男：P=0.002,女：P=0.022）和脂肪含量指数（男：P=0.000,女：P=0.000）呈显著负相关。结论　肥胖儿童AEE与体成分有关,肥胖程度越高,AEE相对值越少。儿童的体型、体成分与能量代谢存在着复杂的联系。     

Energy expenditure, energy intake, and weight loss in Alzheimer disease

Alzheimer disease is one of the leading causes of death among older individuals. Unexplained weight loss and cachexia are frequent clinical findings in patients with Alzheimer disease. Thus, it has been postulated that Alzheimer disease may be associated with dysfunction in body weight regulation. This brief review examines the interrelations among energy intake, energy expenditure, and body composition in Alzheimer disease. We explored whether abnormally high daily energy expenditures, low energy intakes, or both contribute to unexplained weight loss and a decline in nutritional status. Specifically, we considered studies that examined energy intake, body composition, and daily energy expenditure and its components. The application of doubly labeled water and indirect calorimetry to understand the etiology of wasting has increased our knowledge regarding the relation among energy expenditure, physical activity levels, and body composition in Alzheimer disease patients. Although the number of studies are limited, results do not support the notion that a hypermetabolic state contributes to unexplained weight loss in Alzheimer disease, even in cachectic patients. Recent findings are presented suggesting an association between abnormally elevated levels of physical activity energy expenditure and elevated appendicular skeletal muscle mass and energy intake in Alzheimer disease patients. Clinical strategies aimed at developing lifestyle and dietary interventions to maintain adequate energy intake, restore energy balance, and maintain skeletal muscle mass should be a future area of investigation in Alzheimer disease research.     

Energy expenditure and body composition during weight reduction in hyperplastic obese women

The energy expenditure and body composition changes in out-patients during a long-term weight reduction with a diet recommended to provide 1100 kcal were studied in eight hyperplastic obese women. The study was focused on finding plausible explanations for the decreasing weight loss rate after several weeks of successful weight reduction. Using a heart rate monitoring method, the energy expenditure was measured four times at selected intervals during the study. Then, the energy intake was calculated on the basis of three dietary recordings lasting from 4 to 7 days. The recorded energy intake increased at the end of the weight reduction, but no changes in daily energy expenditure were found. The oxygen consumption during standardized cycling, walking, and domestic work decreased, but when the patient was at rest, no changes occurred during the weight reduction. The weight loss predicted from the energy balance and body composition changes was considerably greater than the actually determined weight loss. Large discrepancies were found after 5 weeks on the weight reducing regimen between the recorded dietary intake and what could be calculated from urinary nitrogen losses. With the available methods for determining energy intake and expenditure, it was considered impossible to fully explain the reason for the weight plateau observed after long-term weight reduction in out-patients.     

Total and regional body composition and energy expenditure in multiple symmetric lipomatosis

AIMS: The aim of the present study was to investigate possible alterations in body composition and resting energy expenditure (REE) in type 1 multiple symmetric lipomatosis (MSL). SUBJECTS AND METHODS: Thirteen men aged from 40 to 78 years affected by type I MSL were compared with 13 healthy control subjects. Fat mass (FM) and fat-free mass (FFM) were determined by DEXA using both standard analysis and specifically for the lipomatous region. REE was measured by indirect calorimetry. RESULTS: FM was higher in MSL subjects at proximal arm level, but significantly lower at distal leg level than in controls (left 1.63+/-0.55 vs. 2.26+/-0.49 kg, P<0.05; right 1.63+/-0.53 vs. 2.40+/-0.54 kg, P<0.01). Arm FFM was similar in the two groups, while distal leg FFM was significantly lower in MSL cases (left: 7.8+/-1.3 vs. 8.7+/-0.8 kg, P<0.05; right: 8.0+/-1.5 vs. 9.2+/-0.9 kg, P<0.05). FFM strongly correlated with REE (r:0.86;P<0.001). REE, expressed as an absolute value and adjusted for FFM (1830+/-215 vs. 1675+/-120 kcal, P<0.05) was higher in MSL patients. CONCLUSION: In conclusion, MSL patients had a marked FFM and FM atrophy in the lower segments of the legs and an altered energy expenditure (hypermetabolism).     

A structured diet and exercise program promotes favorable changes in weight loss, body composition, and weight maintenance

Background

A number of diet and exercise programs purport to help promote and maintain weight loss. However, few studies have compared the efficacy of different methods.

Objective

To determine whether adherence to a meal-replacement–based diet program (MRP) with encouragement to increase physical activity is as effective as following a more structured meal-plan–based diet and supervised exercise program (SDE) in sedentary obese women.

Design

Randomized comparative effectiveness trial.

Participants/setting

From July 2007 to October 2008, 90 obese and apparently healthy women completed a 10-week university-based weight loss trial while 77 women from this cohort also completed a 24-week weight maintenance phase.

Intervention

Participants were matched and randomized to participate in an MRP or SDE program.

Main outcome measures

Weight loss, health, and fitness-related data were assessed at 0 and 10 weeks on all subjects as well as at 14, 22, and 34 weeks on participants who completed the weight maintenance phase.

Statistical analyses performed

Data were analyzed by multivariate analysis of variance for repeated measures.

Results

During the 10-week weight loss phase, moderate and vigorous physical activity levels were significantly higher in the SDE group with no differences observed between groups in daily energy intake. The SDE group lost more weight (−3.1±3.7 vs −1.6±2.5 kg; P=0.03); fat mass (−2.3±3.5 vs −0.9±1.6 kg; P=0.02); centimeters from the hips (−4.6±7 vs −0.2±6 cm; P=0.002) and waist (−2.9±6 vs −0.6±5 cm; P=0.05); and, experienced a greater increase in peak aerobic capacity than participants in the MRP group. During the 24-week maintenance phase, participants in the SDE group maintained greater moderate and vigorous physical activity levels, weight loss, fat loss, and saw greater improvement in maximal aerobic capacity and strength.

Conclusions

In sedentary and obese women, an SDE-based program appears to be more efficacious in promoting and maintaining weight loss and improvements in markers of health and fitness compared to an MRP type program with encouragement to increase physical activity.