Ghrelin secretion in severely obese subjects before and after a 3-week integrated body mass reduction program

Ghrelin, the endogenous ligand of GH-secretagogue receptors, has been implicated in the regulation of feeding behavior and energy balance. Aim of the study was to investigate ghrelin levels in fasting conditions and after a standard meal test in obese subjects before and after a 3-week integrated body weight reduction (BWR) program (consisting of energy-restricted diet, exercise training, psychological counselling and nutritional education). Weight, height, fat mass, fat free mass (by impedentiometry), circulating ghrelin, insulin and leptin levels were evaluated in 10 obese subjects (3 male, 7 female; mean age: 35 +/- 9.3 yr; body mass index BMI: 45.2 +/- 10.6 kg/m2) before and after weight reduction. At baseline, obese subjects showed significantly lower ghrelin levels than controls, which were negatively correlated with BMI, weight, insulin and leptin levels. Fasting ghrelin levels were not modified by standard meal test in obese subjects (from 110.8 +/- 69.7 to 91.8 +/- 70.2 pmol/l p=ns), while a significant reduction was observed in controls (from 352.4 +/- 176.7 to 199.0 +/- 105.2 pmol/l; p<0.01). After a 3-week integrated BWR program obese subjects significantly reduced weight, BMI and leptin levels, while no significant changes were found both in fasting ghrelin and in ghrelin response after the meal. In conclusion, 5% weight loss obtained after a short-term period of integrated BWR program is not sufficient to normalize fasting ghrelin levels nor to restore the normal ghrelin suppression after a meal in severely obese subjects.     

Changes of autonomic cardiac profile after a 3-week integrated body weight reduction program in severely obese patients

The autonomic control of the heart is abnormal in obese subjects due to a prevalence of sympathetic over parasympathetic limb of the autonomic balance. We evaluated the effects of a short-term (3 weeks) integrated body weight reduction program (consisting of energy restricted diet and high-intensity exercise training) on heart rate variability (HRV) in severely obese, normotensive patients. The HRV was evaluated both in the time and frequency domain over a 18-hour Holter recording period obtained before and at the end of the third week. Three-week body weight reduction program reduced BMI (from 41.4 +/- 4.6 to 39.5 +/- 4.3 kg/m2, -4.6%, p<0.0001) and heart rate (from 77.8 +/- 8.6 to 73.6 +/- 8.7 b/min, p=0.0003). Significant changes in the autonomic profile were observed both in the time and frequency domain (SD of RR interval, SDRR: +16.1%; mean squared successive difference: (MSSD) +16.7%; percentage of RR intervals differing more than 50 msec from the preceding one, pNN50: +31.8%; low frequency oscillation, LF: +17.1%; high frequency oscillation, HF: +/- 18.2%). In conclusion, this study demonstrates that a short-term, integrated body weight reduction program is able to favorably modify the autonomic profile in a population of normotensive, severely obese subjects. The reduction of heart rate and the increase in parasympathetic activity may consistently contribute to a reduction of the risk of cardiovascular morbidity and of sudden cardiac death, still high in this patients' group.     

Effect of a 3-week body mass reduction program on body composition, muscle function and motor performance in pubertal obese boys and girls

The aim of this study was to investigate the effects of a multidisciplinary body mass reduction (BMR) program on body composition, muscle function and motor performance in 50 obese [mean body mass index (BMI): 35.9+/-5.8 kg/m2] boys and girls aged 12-17 yr (Tanner stage III, IV and V). The hospital-based BMR program combined an energy-restricted diet (1400-1600 kcal), nutritional education, psychological counselling and moderate physical activity (45-60 min/ session; 5 sessions/week; 60-80% of the maximal heart rate) during a 3-week period. Fat mass, fat-free mass, maximal power during jumping and stair climbing as well as maximal strength of the upper and lower limb muscles were quantified before and after the treatment. Body mass and fat mass significantly decreased following the BMR program, respectively -5.1 and -7.8% (p<0.001), while percent fat-free mass increased 2.3% (p<0.001). The treatment significantly increased both stair climbing and jumping power, respectively 8.2 and 8.9% (p<0.05), and the same was true for maximal strength of the upper and lower limb muscles (p<0.001). For the first time, it was demonstrated that a BMR program entailing diet and physical exercise significantly improved body composition, muscle function and motor performance in obese boys and girls aged 12-17 yr, while gender and pubertal stages had no influence on BMR program-induced changes.     

Effects of alpha-lipoic Acid on body weight in obese subjects

Purpose

Alpha-lipoic acid is an essential cofactor for mitochondrial respiratory enzymes that improves mitochondrial function. We previously reported that alpha-lipoic acid markedly reduced body weight gain in rodents. The purpose of this study was to determine whether alpha-lipoic acid reduces body weight in obese human subjects.

Methods

In this randomized, double-blind, placebo-controlled, 20-week trial, 360 obese individuals (body mass index [BMI] ≥30 kg/m² or BMI 27-30 kg/m² plus hypertension, diabetes mellitus, or hypercholesterolemia) were randomized to alpha-lipoic acid 1200 or 1800 mg/d or placebo. The primary end point was body weight change from baseline to end point.

Results

The 1800 mg alpha-lipoic acid group lost significantly more weight than the placebo group (2.1%; 95% confidence interval, 1.4-2.8; P < .05). Urticaria and itching sensation were the most common adverse events in the alpha-lipoic acid groups, but these were generally mild and transient.

Conclusion

Alpha-lipoic acid 1800 mg/d led to a modest weight loss in obese subjects. Alpha-lipoic acid may be considered as adjunctive therapy for obesity.     

Elderly obese women display the greatest improvement in stair climbing performance after a 3-week body mass reduction program

OBJECTIVE: To investigate whether stair climbing performance and body composition are similarly affected by a body mass reduction (BMR) program in obese individuals of different gender, age and body mass index (BMI) level. DESIGN: Longitudinal, clinical intervention study entailing energy-restricted diet (5023-7535 kJ/day), nutritional education, psychological counselling and moderate physical activity (indoor cycling, outdoor walking, gymnastics routines, five sessions/week) during a 3-week period. SUBJECTS: A total of 466 male and 807 female subjects categorized as a function of gender, age (< vs >/=50 y) and BMI (< vs >/=40 kg/m(2)). MEASUREMENTS: Body mass, stair climbing time and power before and after the BMR program. Fat-free mass and fat mass were also evaluated by bioimpedance analysis, in a representative subgroup of 160 patients, to evaluate the relation between fat-free mass and power output. RESULTS: Body mass, fat-free mass and fat mass significantly decreased following the BMR program (P<0.001), with male subjects reducing body mass and fat-free mass more than and fat mass less than the female subjects. Stair climbing time decreased (P<0.001) and therefore anaerobic power significantly increased 9.7% after the treatment. The greatest improvement in stair climbing performance was observed in obese women aged >/=50 y. Significant inverse correlations were found between initial power or fat-free mass level and respective percent increases (R=-0.35/-0.37, P<0.001) and between BMR-induced percent changes in body mass and power (R=-0.13, P<0.001). CONCLUSION: Subjects with the lowest baseline level in stair climbing performance (and probably with the lowest amount of fat-free mass), that is, obese women aged more than 50 y, obtained the largest enhancement after the 3-week BMR program, likely improving overall functional capacities and resulting in greater independence during daily-living activities in such a population.     

Effects of a multidisciplinary weight loss intervention on body composition in obese adolescents

OBJECTIVE: To investigate if a multidisciplinary weight loss program in adolescents suffering severe obesity allows adequate growth and development and avoid lean mass loss. DESIGN: A total of 55 adolescents (33 girls and 22 boys) suffering severe obesity were enrolled in an interdisciplinary weight reduction program lasting 6-12 months. Progressive submaximal physical activity was performed and national dietary allowances for adolescents with low levels of physical activity energy were provided. MEASUREMENTS: Total and segmental body composition was assessed by means of dual-energy X-ray absorptiometry. RESULTS: The mean height significantly increased (P<0.001). The mean body mass index (BMI) dropped in boys from 34.5+/-3.2 to 25.5+/-2.3 kg/m(2) and in girls from 38.4+/-4.1 to 28.4+/-4.1 kg/m(2). Height increased according to the expected pattern (P<0.001). Total lean mass (LM) did not vary and was positively correlated to pubertal development in both sexes before and after weight loss. Steepest drop in fat mass (FM) was observed in the trunk (-63.2+/-10.1% in boys and -51.5+/-11.4% in girls). Decrease in BMI and FM was tightly correlated in both sexes. However, slopes significantly differed (P<0.0005) so that a decrease of 1 kg/m(2) in BMI corresponded to a decrease of 3.92 kg in FM in girls and of 5.44 kg in boys. In each sex, FM at baseline and duration of the treatment were the main determinants of the decrease in FM. CONCLUSION: During adolescence, despite a major weight loss, adequate growth and preservation of LM can be achieved. Weight loss kinetics markedly differs between boys and girls. Low-calorie diets are unnecessary to achieve a marked reduction of severe obesity during puberty.     

Effects of intermittent walk program on the body mass and composition in obese women

The obese patients adhere weakly to rehabilitation programs; therefore the expected gains are often disappointing. This is possibly linked to the monotony of constant velocity exercises frequently proposed. Consequently, other less monotonous exercises such as the intermittent walk may be more appropriated. OBJECTIVES: The main objectives of this study were to determine if the obese women prefer a constant velocity walk or an intermittent walk, and to analyze the effects of a rehabilitation program based on the intermittent walk. MATERIALS AND METHODS: Twenty obese women were recruited. To determine the preferred walk modality, 10 obese women performed a constant velocity walk and an intermittent walk (with a similar duration and velocity) on a treadmill. The preferred walk modality was determined by lower ratings of perceived exertion. Then, these same 10 women participated in a rehabilitation program of 10 weeks (three days per week) consisting of intermittent walks. The 10 other women did not participate in a training program. RESULTS: The ratings of perceived exertion were not significantly different between the two walk modalities. However, the women who participated in a training program increased their maximal distance during a 6 min walking test and they have stabilized theirs anthropometric data. Meanwhile, the untrained women have increased their body mass, body mass index and percentage of body fat. CONCLUSION: The obese patients preferred similarly the constant velocity walk and the intermittent walk, and a rehabilitation program based on an intermittent walk is effective in avoiding the obesity aggravation.     

Changes in the profile of circulating HDL subfractions in severe obese adolescents following a weight reduction program

Background and aimsEpidemiological studies show that obese adolescents are candidates to suffer cardiovascular pathologies in adulthood. In order to detect subfractions with a diagnostic value for future cardiovascular disorders, we analyzed the complete lipoprotein profile of severely obese adolescents.Methods and resultsTwenty-eight obese adolescents free from comorbidities were admitted into a weight reduction program. Anthropometric parameters were monitored. The circulating lipoproteins and glycemia were measured at the beginning and at the end of the study by conventional blood analysis as well as by using lipoprotein electrophoresis. Twenty-one puberty-matched normal-weight adolescents were recruited as controls. After 4 months, participants improved anthropometric parameters. Blood analysis indicated that circulating lipoproteins were in the healthy range during intervention. Nevertheless, results obtained from lipoprotein electrophoresis showed a significant increase in the large high-density lipoprotein subfraction in the obese population at the end of intervention, but significantly lower than normal-weight counterparts. In addition, intermediate- and low-density lipoprotein subfractions were in the healthy range in controls and in obese adolescents during intervention.ConclusionsAltogether, it seems that the obese adolescents with no comorbidities do not develop a clear dyslipidemia. However, low values of large high-density lipoprotein subfractions could be considered as candidate predictors to develop cardiovascular disease in the future. For this reason, diet and exercise are key tools to fight against this pathology.Registration number for clinical trialsISRCTN99414527     

Changes of haemostasis in obese subjects during weight reduction

In a group of 126 obese subjects hospitalized at the obesitological unit of the Gerontological and Metabolic Clinic, Faculty Hospital Hradec Králové the authors confirmed the effect of short-term modified fasting and a low energy diet on the body weight and body mass index They also proved the influence of weight reduction on normalization of cholesterol and LDL-cholesterol and triacylglycerols. They did not prove however the influence of short-term modified fasting and a low energy diet on the concentration of some coagulation pareameters (fibrinogen, D-dimers, antithrombin). In the patients a decline of the fibrinolytic activity was observed and an increase of the fibrinolytic capacity. The authors found a close correlation between the decline of the inhibitor of plasminogen-1 activator, an indicator of the fibrinolytic activity, and body weight and lipid changes. The authors proved a close negative correlation between the rise of fibrnolytic capacity and changes of body weight and lipids. In conjunction with the presented results and based on data from the lierature it may be stated that a decline of body weight in obese subjects reduces the risk of the syndrome of insulin resistance. Activation of fibrinolysis in insulin resistance depends directly on the amount of visceral fat and changes of te fibrinolytic properties of blood in obese subsjects depend on the production of PAI-1 by adipocytes of visceral fat.     

Changes in fat-free mass in obese subjects after weight loss: a comparison of body composition measures.

Estimates of body composition by densitometry were made in 84 apparently healthy subjects (42 men, 42 women) with a mean age of 40 +/- 6 years (mean +/- s.d.), before and after weight loss. The initial body mass index (BMI) was 30.7 +/- 2.3 kg/m2 and the achieved weight loss on a 4.2 MJ/day energy deficit diet for 13 weeks was 12.2 +/- 3.7 kg. The results by densitometry were compared with estimates obtained by four other techniques: deuterium oxide dilution, skinfold thickness, bioelectrical impedance (three equations) and BMI (two equations). The fat-free mass (FFM) loss estimated by densitometry in men and women was 2.8 +/- 1.8 kg and 1.3 +/- 1.3 kg respectively. The dilution technique gave comparable results with densitometry. The losses of FFM assessed by skinfold thicknesses, BMI and impedance equations were almost similar, but significantly larger than the reduction in FFM measured by densitometry. These deviations were mainly the result of significantly larger differences from densitometry before compared to after weight loss. No correlation was found between change in FFM by densitometry and change in resistance measured by the bioelectrical impedance method in both sexes. It is concluded that application of published prediction formulae in weight loss studies are less appropriate and will lead to changes in FFM that are significantly different from the changes estimated by densitometry or deuterium oxide dilution.     

Effects of cigarette smoking and its cessation on body weight and plasma leptin levels.

Smokers weigh less than age-matched nonsmokers, and most smokers gain weight after smoking cessation due to an increase in food intake and a decrease in energy expenditure. Leptin is an endocrine signal thought to regulate body fat stores through hypothalamic control of energy intake and expenditure. To determine whether the "weight-reducing" effects of smoking may be mediated by leptin, we measured plasma leptin concentrations in 22 middle-aged and older male smokers (body mass index [BMI], 28 +/- 1 kg/m2, mean +/- SEM) and 22 nonsmokers matched to the smokers for age (64 +/- 1 years) and BMI (28 +/- 1 kg/m2). The body weight and leptin concentration were remeasured at 3 and 6 months in 13 of the smokers who successfully stopped smoking. The leptin concentration correlated positively with the BMI in both smokers (r = .74, P < .001) and nonsmokers (r = .76, P < .001). However, the intercept of the regression line was higher for smokers versus nonsmokers (P < .05), with no difference in the slope. Thus, male smokers have a higher leptin level for a given BMI than nonsmokers. Following 6 months of smoking cessation, body weight increased by 7% (6.0 +/- 0.1 kg, n = 13, P < .01). Despite this weight gain, the mean leptin concentration did not increase with smoking cessation. On average, leptin levels were 25% lower than would be expected for the amount of weight gained after smoking cessation. These findings suggest that cigarette smoking directly elevates circulating plasma leptin concentrations, and this increase may be one mechanism for the lower body weight of smokers compared with nonsmokers.     

Postural instability of extremely obese individuals improves after a body weight reduction program entailing specific balance training

The purposes of this study were to compare postural stability between obese and lean subjects and to investigate the effect of a 3-week body weight reduction (BWR) program entailing specific balance training on postural stability of extremely obese patients. Time of balance maintenance and mean error on the medial-lateral direction at the trunk and lower limb level were assessed during a single limb stance on a movable platform in 19 non-obese and in 20 extremely obese individuals (age range: 20-40 yr). Time of balance maintenance was shorter (obese: 21.1+/-7.7 vs lean: 27.3+/-3.1 sec) and medial-lateral sway of the trunk was larger in obese (5.4+/-3.2 degrees) than in lean (3.2+/-1.1 degrees) subjects (p<0.05). Two subgroups of obese subjects were also tested after a BWR program (energy-restricted diet, moderate physical exercise, nutritional education and psychological counselling) combined with or without 6 sessions of specific balance training on a movable platform. BWR plus specific balance training enhanced time of balance maintenance (pre: 23.8+/-7.2 vs post: 30.0+/-0.0 sec) and reduced the trunk sway (5.2+/-2.8 degrees vs 2.6+/-0.9 degrees ) more than BWR alone (p<0.05). The present findings indicate that extremely obese individuals have inadequate postural stability (compared to their lean counterparts) that could however be improved by few sessions of specific balance training incorporated into a multidisciplinary BWR program. It was concluded that balance improvement is an important goal of rehabilitation, that would probably reduce the propensity of overweight individuals to fall while performing everyday activities.     

Effects of diet-induced moderate weight reduction on intrahepatic and intramyocellular triglycerides and glucose metabolism in obese subjects

CONTEXT: Although moderate weight reduction is recommended as primary therapy of metabolic syndrome, little information is known regarding metabolic changes associated with moderate weight reduction in nondiabetic obese subjects. OBJECTIVE: The aim of this study was to determine the effects of a moderate weight reduction program on intracellular lipid and glucose metabolism in muscle and liver. PARTICIPANTS: Data for 13 nondiabetic obese subjects were evaluated. INTERVENTION: Subjects were put on a 3-month mildly hypocaloric diet therapy (approximately 35 kcal/kg of ideal body weight). MAIN OUTCOME MEASURES: Intrahepatic lipid (IHL) and intramyocellular lipid were measured by using (1)H magnetic resonance spectroscopy. Peripheral insulin sensitivity and splanchnic glucose uptake were evaluated by euglycemic-hyperinsulinemic clamp with oral glucose load. RESULTS: Diet therapy for 3 months resulted in 6% reduction in body weight (from 99.9 +/- 7.3 to 93.8 +/- 6.6 kg, P < 0.0001). This change was accompanied by reduction of plasma glucose and insulin excursions during 75-g oral glucose tolerance tests, decrease in diastolic blood pressure, glycated hemoglobin, serum low-density lipoprotein cholesterol, and triglyceride. These changes were also accompanied by a decrease in IHL (from 12.9 to 8.2%, P < 0.01) and increase in splanchnic glucose uptake (from 13.5 to 35.0%, P < 0.03). On the other hand, the diet program did not affect intramyocellular lipid or glucose infusion rate during euglycemic hyperinsulinemic clamp. CONCLUSIONS: Our results suggest that moderate weight reduction in obese subjects decreased IHL and augmented splanchnic glucose uptake. This mechanism is at least in part involved in improvement of glucose metabolism by moderate weight reduction in obese subjects.     

Effect of a multidisciplinary program of weight reduction on endothelial functions in obese women

Obesity is associated with an increased risk of developing atherosclerosis and atherosclerotic lesions are essentially an inflammatory response. The aim of this study was to evaluate the effect of a medically supervised, multidisciplinary weight loss program on endothelial functions and circulating levels of proinflammatory cytokines in obese women. Twenty healthy pre-menopausal obese women and 20 age-matched normal weight women were studied. Endothelial functions were assessed by evaluating the response of blood pressure and platelet aggregation to an intravenous bolus of L-arginine (3 g), the natural precursor of nitric oxide. In obese women, the vascular and rheological responses to L-arginine were significantly lower (p < 0.05) at baseline, as compared with non-obese women, indicating endothelial dysfunction; on the contrary, basal concentrations of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) were significantly higher (p < 0.01). After one year of a multidisciplinary program of weight reduction consisting of diet, exercise and liposuction surgery, all obese women lost at least 10% of their original weight (10.5 +/- 1.7 kg, range 7.9-13.9 kg). Compared with baseline, sustained weight loss was associated with reduction of cytokine (p < 0.01) concentrations and with improvement of vascular responses to L-arginine. In conclusion, a multidisciplinary approach aimed at inducing a sustained reduction of body weight in obese women is feasible and is associated with improvement of endothelial functions and reduction of circulating proinflammatory cytokine concentrations.     

Resting energy expenditure and body composition in morbidly obese,obese and control subjects

Resting energy expenditure (REE) was investigated by indirect calorimetry in relation to body composition and to different degrees of obesity in order to assess if a defective energy expenditure contributes to extra body fat accumulation. Differences were found between control subjects (group C; BMI 23±0.5 kg/m², REE 5890±218 kJ/day; mean±SEM) and obese subjects (group O; BMI 34.2±0.9 kg/m², REE 7447±360 kJ/day;P<0.0001) and between group C and morbidly obese subjects (group MO; BMI 49.9±1.6 kg/m², REE 8330±360 kJ/day;P<0.0001); REE was not significantly different between groups O and MO. Body composition data were obtained by means of body impedance analysis. Even though group MO had a fat mass higher than group O, body cell mass, the metabolically active body compartment, was similar in groups O and MO, and this fact may have contributed to the similar REE in the two groups. Multiple regression analysis gave the following equation as the best predictor of REE: REE (kJ/day)+1591±49_BW+74_BCM–737 _G (R ²=0.88), where BW is body weight, BCM is body cell mass andG is a dummy variable coding group membership (group C=1; group O=2; group MO=3). Thus the analysis showed a negative impact of obesity on REE beyond body composition variables.     

Effects of an aerobic exercise program and diet on body composition and cardiovascular function in obese persons

The purpose of this study was to determine the effect of a combination of aerobic exercise and hypocaloric diet on body composition, cardiovascular function and some cardiovascular risk factors in obese patients. Ten subjects, (8 women 2 men X age 30 years and 138% of ideal body weight) volunteered as participants. The program lasted 12 weeks and consisted of a hypocaloric diet (1257 kcal/day) and 3-5 days/week supervised sessions of aerobic exercise (65-90% maximal heart rate and/or 50-80% of maximal oxygen uptake). The program resulted in a significant mean decrease in body weight of 7.7 kg. for the group (P less than or equal to 0.05). Mean (+/- EE) relative body fat significantly decreased from 35.9 +/- 2 to 31.6 +/- 2%. Interestingly, the decrease in relative body fat was solely accounted for by a significant decrease in fat weight, as body free of fat remained constant. Cardiovascular function as evidenced by oxygen uptake, increased 11.3%. Resting systolic and diastolic blood pressure fell significantly from 131/90 +/- 8/9 to 115/76 +/- 2/1 mmHg. Total cholesterol significantly dropped from a mean value of 247 +/- 24 to 183 +/- 20 mg/100 ml (P less than 0.05). Triglycerides significantly decreased from 212 +/- 32 to 45 +/- 10 mg/100 ml (P less than 0.05). It was concluded that a combination of aerobic exercise and hypocaloric diet can favorably improve body composition, cardiovascular function and cardiovascular risk factors.     

Effects of non-specific vs individualized exercise training protocols on aerobic,anaerobic and strength performance in severely obese subjects during a short-term body mass reduction program

The purpose of the present study was to compare aerobic, anaerobic and strength performance changes induced by two short-term (3-week) body mass reduction programs based on the same low-calory diet (1200-1500 kcal/day), nutritional education and psychological counseling, but entailing different exercise training protocols. An individualized, low-volume and moderate-intensity exercise training (IET) was contrasted with a non-specific, high-volume, low-intensity exercise training (NET). Thirty obese in-patients (12 males, 18 females; mean age +/- SD: 33.9 +/- 9.4 yr, range: 19-51yr; mean BMI: 40.5 +/- 3.8 kg/m2, range: 35.3-51.4 kg/m2) were randomly divided in two gender-matched groups of 15 subjects each undergoing a different exercise training protocol. Maximum oxygen uptake (VO2max) determined with a submaximal indirect test on a bicycle ergometer, lower limb maximum power output (W(max)) determined with the jumping method, global motor capabilities determined by analysis of locomotor pattern during a short (8 m) running, maximum strength (1-RM) of upper and lower limb muscle groups determined with isotonic machines were tested before and after the program. Adherence to an individual exercise activity and maintenance of body weight (bw) loss were evaluated with a telephonic interview 6 months after the completion of the program. In both groups a significant (p < 0.001) and comparable weight loss was observed (IET: -4.27%; NET: -4.17%). In both groups VO2max and W(max) increased significantly (p < 0.05-0.001) when expressed relatively to body mass, while in absolute terms they were significantly (p < 0.001) improved only in IET group. 1-RM in all tested muscle groups was significantly increased in both IET and NET subjects (p < 0.001-0.01), but improvements were significantly greater in IET as compared with NET (p < 0.05-0.001). The analysis of locomotor pattern during the short running indicated that IET subjects significantly improved their global motor capabilities (p < 0.05-0.001), while no change was observed in NET group. After 6 months, IET subjects reported a level of spontaneously chosen physical activity significantly higher (p < 0.05) than NET subjects, displaying a trend of further decrease in bw. It was concluded that, although no difference in bw loss was appreciated between the two studied groups and significant improvements were found also in subjects performing NET protocol, the IET protocol offers better overall results in terms of muscle performance and physical fitness, with a possibly stronger motivation to subsequent exercise activity.     

Effects of weight cycling caused by intermittent dieting on metabolic rate and body composition in obese women

The effects of repeated periods of weight loss and regain on metabolic rate and body composition were investigated in 11 obese women (mean weight 81.98 kg, height 1.61 m, body mass index 31.44 kg/m2) studied for 18 weeks through three consecutive cycles of 2 weeks dieting followed by 4 weeks ad libitum eating. Weight loss was achieved by a very low energy diet (1861 kJ/day). Basal metabolic rate (BMR) was measured by whole-body indirect calorimetry and body composition by a variety of standard in vivo methods. During the three diet periods mean weight losses were 4.44, 3.29 and 2.98 kg although the mean overall weight loss from week 0 to 18 was only 5.93 kg. The proportion of weight lost as fat was estimated as between 67 and 105 per cent of the weight lost depending on the body composition methodology employed. Absolute BMR decreased in response to dieting by 545, 285 and 286 kJ/day. When corrected for body weight and FFM only the decreases in the first diet period were significant (P less than 0.05 and P less than 0.001 respectively). BMR had returned to normal following each 4-week ad libitum period and by the end of the study absolute BMR and BMR/kg FFM had not changed significantly, despite a significant loss of weight. Consequently BMR/kg was increased (P less than 0.01), indicative of the loss of adipose tissue. We have found no evidence in this group of obese women that weight cycling leads to a progressive decrease in BMR or increase in the proportion of body fat.