Effect of weight and body composition changes on waist measurement of severely obese women receiving carbohydrate-restricted diet

OBJECTIVE: To evaluate the effect of weight and body composition changes on waist measurement of severely obese women receiving a low-carbohydrate diet for a short-term. METHODS: Nineteen severely obese women divided into an intervention and a control group received a low-carbohydrate diet and a conventional diet, respectively, both with 1,200kcal, for seven days. Anthropometric measurements such as weight, body mass index, arm circumference, waist circumference (at the navel), two proposed measurements of waist circumference (waist circumference 1, 10cm above the navel; and waist circumference 2, 20cm above the navel), hip circumference; and body composition (lean mass and fat mass) were performed at baseline and end of the study. RESULTS: There was significant reduction of all variables in the intervention group (p<0.01), but the control group had no change in waist circumference (p=0.06) and hip circumference (p=0.36). Patients of the intervention group presented greater weight loss (4.4kg, p<0.01) and reduction of body mass index, waist circumference, waist circumference 1, waist circumference 2 (p<0.01), and fat mass (p=0.04) than the control group. CONCLUSION: The weight loss and body composition changes were greater in the low-carbohydrate group than in the conventional-diet group, and they had a greater impact on waist measurements. The proposed measurements (waist circumference 1 and waist circumference 2) were sensitive to weight reduction in both groups.

研究目的：评估短期低碳水化合物饮食对重度肥胖女性体重及身体成分变化与腰围测量值的影响。
研究方法：将19名重度肥胖女性分为干预组与对照组，两组饮食的每日热量均为1200千卡，其中干预组采用低碳水化合物饮食，对照组采用常规饮食，干预周期为7天。分别于基线及研究结束时采集多项人体测量学指标，包括体重、身体质量指数（Body Mass Index）、上臂围、脐周腰围、两种自定义腰围测量方式（腰围1：脐上10cm处；腰围2：脐上20cm处）、臀围；同时检测身体成分指标，包括瘦体重与体脂质量。
研究结果：干预组所有观测指标均出现显著降低（p<0.01）；对照组的腰围（p=0.06）与臀围（p=0.36）则无显著变化。相较于对照组，干预组患者的体重下降幅度更为显著（4.4kg，p<0.01），且身体质量指数、腰围、腰围1、腰围2及体脂质量的降低幅度均显著优于对照组（p<0.01，p=0.04）。
研究结论：相较于常规饮食组，低碳水化合物饮食组的体重下降及身体成分改善更为显著，且对腰围测量值的影响更为突出。本次研究提出的两种自定义腰围测量方式在两组受试者中均对体重减轻具有敏感性。