肥胖婦女減重前後體組成及熱量代謝之變化

Changes of Body Composition and Energy Metabolism in Obese Women before and after Weight Reduction

葉松鈴(Sung-Ling Yeh) ； 劉美媛(Mei-Yuan Liu) ； 陳維昭(Wei-Jao Chen)

《中華民國營養學會雜誌》 23卷2期 (1998/05) Pp. 133-145

https://doi.org/10.6691/JCNS.199805_23(2).0002

摘要

Following the rapid economic progress in Taiwan, the prevalence of overweight increases in recent years. Although most obese people are willing to lose weight, weight relapse is common in the obese population. Regulation of energy metabolism is an important factor in body weight control. Studies on the comparison of energy metabolism before and after weight reduction for domestic people are rare. The aim of this study was to investigate the differences of anthropometry, body composition and energy metabolism between obese and nonobese women. Besides, the changes of these parameters before and after weight reduction were also studied. Sixty-seven premenopausal obese women were recruited into the study, and consequently divided into mildly obese group with their body mass index (BMI) ranged from 26.4 to 30.7, and moderately obese group with BMI over 30.8. All obese women were kept on low calorie diet for half an year. Twenty-nine women reduced weight for more than 5% of their initial body weight. Eighteen age matched women of normal weight served as control. The results revealed that, triceps skinfold thickness (TSF), mid arm muscle circumference (MAMC), fat mass (FM), and fat free mass (FFM) increased in accordance with BMI. After weight reduction, all the anthropometric measurements in obese women decreased significantly. TSF was positively correlated with fat mass. Decrease of TSF after weight loss, therefore, can be used as an indicator of reduction of body fat mass. The absolute resting metabolic rate (RMR) was significantly higher in the obese than in the nonobese women, however, no difference in the RMR/FFM ratio was seen among all groups. RMR/body weight ratio was significantly lower in the moderately obese group than in the nonobese group. These results indicated that, although metabolically active FFM increased in parallel with body weight, the percentage of FFM in obese women was relatively low in same level of body weight, so that obese women were relatively hypometabolic as compared to nonobese women. RMR decreased after weight loss with the reduction of FFM and FM. This might be responsible for the failure to maintain a constant weight loss and weight relapse of obese subjects. No difference was observed in urinary creatinine and 3-methyhistidine excretion before and after weight reduction, this result suggests that muscle depletion was not obvious in the obese women under the present experimental condition.

關鍵字

肥胖 ； 減重 ； 體組成 ； 休息狀態下之熱量代謝

並列摘要

Following the rapid economic progress in Taiwan, the prevalence of overweight increases in recent years. Although most obese people are willing to lose weight, weight relapse is common in the obese population. Regulation of energy metabolism is an important factor in body weight control. Studies on the comparison of energy metabolism before and after weight reduction for domestic people are rare. The aim of this study was to investigate the differences of anthropometry, body composition and energy metabolism between obese and nonobese women. Besides, the changes of these parameters before and after weight reduction were also studied. Sixty-seven premenopausal obese women were recruited into the study, and consequently divided into mildly obese group with their body mass index (BMI) ranged from 26.4 to 30.7, and moderately obese group with BMI over 30.8. All obese women were kept on low calorie diet for half an year. Twenty-nine women reduced weight for more than 5% of their initial body weight. Eighteen age matched women of normal weight served as control. The results revealed that, triceps skinfold thickness (TSF), mid arm muscle circumference (MAMC), fat mass (FM), and fat free mass (FFM) increased in accordance with BMI. After weight reduction, all the anthropometric measurements in obese women decreased significantly. TSF was positively correlated with fat mass. Decrease of TSF after weight loss, therefore, can be used as an indicator of reduction of body fat mass. The absolute resting metabolic rate (RMR) was significantly higher in the obese than in the nonobese women, however, no difference in the RMR/FFM ratio was seen among all groups. RMR/body weight ratio was significantly lower in the moderately obese group than in the nonobese group. These results indicated that, although metabolically active FFM increased in parallel with body weight, the percentage of FFM in obese women was relatively low in same level of body weight, so that obese women were relatively hypometabolic as compared to nonobese women. RMR decreased after weight loss with the reduction of FFM and FM. This might be responsible for the failure to maintain a constant weight loss and weight relapse of obese subjects. No difference was observed in urinary creatinine and 3-methyhistidine excretion before and after weight reduction, this result suggests that muscle depletion was not obvious in the obese women under the present experimental condition.

並列關鍵字

obesity ； weight reduction ； body composition ； resting metabolic rate