Ross R, Dagnone D, Jones P J, Smith H, Paddags A, Hudson R, Janssen I
School of Physical and Health Education, Queen's University, Kingston, Ontario, Canada.
Ann Intern Med. 2000 Jul 18;133(2):92-103. doi: 10.7326/0003-4819-133-2-200007180-00008.
The independent effects of diet- or exercise-induced weight loss on the reduction of obesity and related comorbid conditions are not known. The effects of exercise without weight loss on fat distribution and other risk factors are also unclear.
To determine the effects of equivalent diet- or exercise-induced weight loss and exercise without weight loss on subcutaneous fat, visceral fat skeletal muscle mass, and insulin sensitivity in obese men.
Randomized, controlled trial.
University research center.
52 obese men (mean body mass index [+/-SD], 31.3 +/- 2.0 kg/m2) with a mean waist circumference of 110.1 +/- 5.8 cm.
Participants were randomly assigned to one of four study groups (diet-induced weight loss, exercise-induced weight loss, exercise without weight loss, and control) and were observed for 3 months.
Change in total, subcutaneous, and visceral fat; skeletal muscle mass; cardiovascular fitness; glucose tolerance and insulin sensitivity.
Body weight decreased by 7.5 kg (8%) in both weight loss groups and did not change in the exercise without weight loss and control groups. Compared with controls, cardiovascular fitness (peak oxygen uptake) in the exercise groups improved by approximately 16% (P < 0.01). Although total fat decreased in both weight loss groups (P < 0.001), the average reduction was 1.3 kg (95% CI, 0.3 to 2.3 kg) greater in the exercise-induced weight loss group than in the diet-induced weight loss group (P = 0.03). Similar reductions in abdominal subcutaneous, visceral, and visceral fat-to-subcutaneous fat ratios were observed in the weight loss groups (P < 0.001). Abdominal and visceral fat also decreased in the exercise without weight loss group (P = 0.001). Plasma glucose and insulin values (fasting and oral glucose challenge) did not change in the treatment groups compared with controls (P = 0.10 for all comparisons). Average improvement in glucose disposal was similar in the diet-induced weight loss group (5.6 mg/kg skeletal muscle per minute) and in the exercise-induced weight loss group (7.2 mg/kg skeletal muscle per minute) (P > 0.2). However, these values were significantly greater than those in the control and exercise without weight loss groups (P < 0.001).
Weight loss induced by increased daily physical activity without caloric restriction substantially reduces obesity (particularly abdominal obesity) and insulin resistance in men. Exercise without weight loss reduces abdominal fat and prevents further weight gain.
饮食或运动引起的体重减轻对肥胖及相关合并症减少的独立影响尚不清楚。未伴随体重减轻的运动对脂肪分布和其他风险因素的影响也不明确。
确定等量的饮食或运动引起的体重减轻以及未伴随体重减轻的运动对肥胖男性皮下脂肪、内脏脂肪、骨骼肌质量和胰岛素敏感性的影响。
随机对照试验。
大学研究中心。
52名肥胖男性（平均体重指数[±标准差]，31.3±2.0kg/m²），平均腰围110.1±5.8cm。
参与者被随机分配到四个研究组之一（饮食引起的体重减轻、运动引起的体重减轻、未伴随体重减轻的运动和对照组），并观察3个月。
总脂肪、皮下脂肪和内脏脂肪的变化；骨骼肌质量；心血管健康状况；葡萄糖耐量和胰岛素敏感性。
两个体重减轻组的体重均下降了7.5kg（8%），未伴随体重减轻的运动组和对照组体重未改变。与对照组相比，运动组的心血管健康状况（峰值摄氧量）提高了约16%（P<0.01）。虽然两个体重减轻组的总脂肪均减少（P<0.001），但运动引起的体重减轻组的平均减少量比饮食引起的体重减轻组多1.3kg（95%可信区间，0.3至2.3kg）（P=0.03）。体重减轻组的腹部皮下脂肪、内脏脂肪以及内脏脂肪与皮下脂肪的比例均有类似程度的降低（P<0.001）。未伴随体重减轻的运动组的腹部和内脏脂肪也减少了（P=0.001）。与对照组相比，各治疗组的血浆葡萄糖和胰岛素值（空腹和口服葡萄糖耐量试验）均未改变（所有比较P=0.10）。饮食引起的体重减轻组（每分钟每千克骨骼肌5.6mg）和运动引起的体重减轻组（每分钟每千克骨骼肌7.2mg）的葡萄糖处置平均改善情况相似（P>0.2）。然而，这些值显著高于对照组和未伴随体重减轻的运动组（P<0.001）。
在不限制热量的情况下，通过增加日常身体活动引起的体重减轻可显著降低男性的肥胖（尤其是腹部肥胖）和胰岛素抵抗。未伴随体重减轻的运动可减少腹部脂肪并防止体重进一步增加。
