Dietary protein and exercise have additive effects on body composition during weight loss in adult women.

This study examined the interaction of 2 diets (high protein, reduced carbohydrates vs. low protein, high carbohydrates) with exercise on body composition and blood lipids in women (n = 48, approximately 46 y old, BMI = 33 kg/m(2)) during weight loss. The study was a 4-mo weight loss trial using a 2 x 2 block design (Diet x Exercise). Diets were equal in total energy (7.1 MJ/d) and lipids ( approximately 30% energy intake) but differed in protein content and the ratio of carbohydrate:protein at 1.6 g/(kg . d) and <1.5 (PRO group) vs. 0.8 g/(kg . d) and >3.5 (CHO group), respectively. Exercise comparisons were lifestyle activity (control) vs. a supervised exercise program (EX: 5 d/wk walking and 2 d/wk resistance training). Subjects in the PRO and PRO + EX groups lost more total weight and fat mass and tended to lose less lean mass (P = 0.10) than the CHO and CHO + EX groups. Exercise increased loss of body fat and preserved lean mass. The combined effects of diet and exercise were additive for improving body composition. Serum lipid profiles improved in all groups, but changes varied among diet treatments. Subjects in the CHO groups had larger reductions in total cholesterol and LDL cholesterol, whereas subjects in the PRO groups had greater reductions in triacylglycerol and maintained higher concentrations of HDL cholesterol. This study demonstrated that a diet with higher protein and reduced carbohydrates combined with exercise additively improved body composition during weight loss, whereas the effects on blood lipids differed between diet treatments.

A reduced ratio of dietary carbohydrate to protein improves body composition and blood lipid profiles during weight loss in adult women.

Claims about the merits or risks of carbohydrate (CHO) vs. protein for weight loss diets are extensive, yet the ideal ratio of dietary carbohydrate to protein for adult health and weight management remains unknown. This study examined the efficacy of two weight loss diets with modified CHO/protein ratios to change body composition and blood lipids in adult women. Women (n = 24; 45 to 56 y old) with body mass indices >26 kg/m(2) were assigned to either a CHO Group consuming a diet with a CHO/protein ratio of 3.5 (68 g protein/d) or a Protein Group with a ratio of 1.4 (125 g protein/d). Diets were isoenergetic, providing 7100 kJ/d, and similar amounts of fat ( approximately 50 g/d). After consuming the diets for 10 wk, the CHO Group lost 6.96 +/- 1.36 kg body weight and the Protein Group lost 7.53 +/- 1.44 kg. Weight loss in the Protein Group was partitioned to a significantly higher loss of fat/lean (6.3 +/- 1.2 g/g) compared with the CHO Group (3.8 +/- 0.9). Both groups had significant reductions in serum cholesterol ( approximately 10%), whereas the Protein Group also had significant reductions in triacylglycerols (TAG) (21%) and the ratio of TAG/HDL cholesterol (23%). Women in the CHO Group had higher insulin responses to meals and postprandial hypoglycemia, whereas women in the Protein Group reported greater satiety. This study demonstrates that increasing the proportion of protein to carbohydrate in the diet of adult women has positive effects on body composition, blood lipids, glucose homeostasis and satiety during weight loss.

Maximal mechanical aerobic and anaerobic power output of low-income Brazilian schoolchildren as a function of growth.

Maximal mechanical aerobic and anaerobic power outpout (POWER) on a cycle-ergometer were measured in 131 children (60 girls and 71 boys) 8 and 9 years of age attending a public school in a low-income area in Rio de Janeiro (RJ), Brazil. Deficits in stature were classified relative to American reference data (NCHS) to identify three groups of children: Group A, Z-score of stature for age (S-Age) ≥ 0 (no deficit); Group B, - 1 < Z S-age < 0 (moderate deficits); and Group C, Z S-age ≤ -1 (greatest deficit). A two-way ANOVA with interaction was used to assess the influence of growth and sex on performance. There were no differences between sexes in anthropometric dimensions but boys had significantly greater estimated upper arm muscle + bone area than girls and also performed better on both tests. Deficits in stature negatively influenced (P < 0.05) aerobic and anaerobic function expressed in absolute values. However, when expressed in relation to body size, POWER and the anaerobic to aerobic ratio values were, in general, not significantly different among the groups. In conclusion, children living in underprivileged environments show deficits in growth, but appear to maintain a level of performance proportional to their smaller body size. From a practical point of view, however, the absolute functional capacity value may be more important, because under such underprivileged conditions, it is the total amount of work produced which determines work capacity in adult life and thus, may determine physical, economic, and social well-being. © 1992 Wiley-Liss, Inc.

Muscular Efficiency during Treadmill Walking: The Effects of Age and Workload.

Changes in muscular efficiency as it relates to age were examined during inclined submaximal treadmill walking in 298 boys ages 7-15 years. Furthermore, the changes in efficiency with increased work intensity (67-90% V̇O2max) were studied. Efficiency was expressed as submaximal oxygen consumption (V̇O2) and was calculated mathematically as energy out/energy in = (vertical distance) (wt of subject)/(V̇O2 L • min-1) (kcal equivalent). Efficiency, calculated mathematically, was found to significantly increase (p<.01) with age, with the younger children (<9 yrs) being less efficient than the older children (13-15 yrs). These values ranged from 12.8% for the youngest boys (<9 yrs) to 16.4% for the oldest boys (13-15 yrs). In addition, efficiency significantly increased in a linear fashion (p<.01) during submaximal workloads within each age group. No significant interactions (p>.05) between age and workload were found. These values are lower than gross efficiency values during cycling previously reported in the literature for adults; however, they support earlier findings that children increase in efficiency with age and work intensity, regardless if expressed as efficiency or V̇O2 (ml • kg-1 •min-1). These findings suggest that parameters associated with growth and development may influence muscular efficiency with age.

Avaliaçäo de componentes da aptidäo física de escolares de baixa renda da Baixada Fluminense, Estado do Rio de Janeiro

Säo poucos os estudos de avaliaçäo de componentes da aptidäo física através de testes físicos em crianças de baixa renda no Brasil. Esse estudo apresenta dados de aptidäo física avaliados através da dinamômetria manual, impulsäo vertical, corrida de 50 m, shuttle run, e teste de sentar e alcançar de 185 crianças (97 garotos e 88 garotas) em idade escolar (7,0 a 10,9 anos) de Nova Iguaçú (NI), Estado do Rio de Janeiro (RJ) cuja renda familiar era em média inferior a 1 salário mínimo. Os garotos mostraram resultados superiores aos das garotas de todas as idades em todo os testes físicos, sendo que foram poucas as diferenças significativas, exceçäo para os dois testes de corrida (shuttle run e corrida de 50 m) quando as diferenças entre os resultados dos garotos e das garotas estatisticamente significativas para todas as idades. Em comparaçäo com dados de crianças da mesma idade da rede pública de ensino de 2 municípios do Estado de Säo Paulo (SP), as criancas de NI pesavam e eram menores em estatura, mas näo mostraram grandes diferenças em termos de resultados nos testes físicos. Esses resultados parecem ser causados por diferenças de comportamento sociais e de padräo de atividade física entre garotos e garotas de NI e entre as crianças do RJ e de SP. Apesar de haver possíveis explicaçöes nutricionais, a falta de avaliaçäo do estado nutricional das crianças impede tal análise

Performance de garotos desnutridos e näo desnutridos em determinados testes físicos / Performance in boys malnourished and better nourished in selected performance field tests

A reduçäo da capacidade física de crianças desnutridas já foi documentada na literatura. Porém, vários problemas de desenho experimental fazem com que os resultados desses estudos sejam difíceis de se interpretar porque fatores como raça, classe sócio-econômica e diferenças culturais em que as crianças vivem näo säo controlados. Portanto esse estudo foi idealizado para se comparar os resultados de determinados testes físicos de garotos desnutridos (DES) e näo desnutridos (N-DES), n= 27 e 65 respectivamente de uma escola de Rede Pública na Baixada Fliminense, Rio de Janeiro. A hipótese a ser testada era a de que os resultados dos testes físicos dos garotos DES seriam significativamente inferiores aos N-DES, mas que poderiam ser comparáveis se esses resultados fossem expressos em relaçäo a índices de massa corporal (IMC). Para todas as medidas antropométricas os DES mostraram valores significativamente inferiores aos N-DES. Näo houve diferença nos resultados absoslutos da dinamometria manual da mäo direita, impulssäo vertical. Shuttle run, e corrida de 50 metros entre os garotos DES e N-DES. Ao se dividir peloas IMC, dois padröes de resposta ocorreram; os garotos DES tiveram valores superiores aos N-DES, na força de preensäo e impulsäo vertical. Nos testes onde o deslocamento do corpo era exigido (Shuttle run e corrida de 50 metros), os DES foram significativamente mais lentos que os N-DES mesmo quando os resultados foram expressos em relaçäo aos IMC. Com base nesses dados os autores concluem que a performance em determinados testes físicos de garotos DES pode ser comparável aos resultados obtidos em garotos N-DES que vivem nas mesmas condiçöes sócio-econômicas e sanitárias e freqüentam a mesma escola pública