Randolph Jody M, Edirisinghe Indika, Masoni Amber M, Kappagoda Tissa, Burton-Freeman Britt
a Department of Nutrition , University of California , Davis , California .
J Am Coll Nutr. 2014;33(5):375-84. doi: 10.1080/07315724.2013.875441. Epub 2014 Oct 10.
The role of glycemic index (GI) and foods with negative attributes related to GI as part of a weight loss regimen has not been thoroughly assessed in free-living individuals. This study examined the effects of a dietary prescription for energy intake modification, GI, and potato consumption on weight loss, dietary prescription adherence, body composition, and glucose control in a free-living, self-selecting overweight population.
Ninety overweight (body mass index [BMI] 29.6 ± 3.9) men and women were randomly assigned to one of 3 groups for 12 weeks. Two groups were counseled to reduce their energy intake by 500 kcal/day and consume diets that were predominantly composed of either low- or high-GI foods (low glycemic index energy reduced [LGI-ER] or high glycemic index energy reduced [HGI-ER] diet, respectively). The third group received no energy restriction, GI provision, or nutritional counseling. All groups were instructed to consume 5-7 servings of potatoes per week. Changes in weight, body composition, glucose tolerance, and triglycerides were determined at baseline and 12 weeks.
There were no significant differences in weight loss or changes in body composition between the groups; however, modest weight loss and body composition changes were seen from week 0 to week 12 for all groups (p < 0.05). Difficulty achieving the prescribed GI diets was evident in this free-living setting. There were no significant changes within or among treatments for fasting concentrations of triglycerides, glucose tolerance, insulin, or insulin sensitivity.
The results indicate that in a free-living population of men and women, weight loss is associated with energy intake reduction. Potato intake did not cause weight gain and following either a high- or low-GI dietary prescription was difficult for free-living subjects, emphasizing the complex nature of changing dietary patterns.
血糖生成指数（GI）以及具有与GI相关负面属性的食物在自由生活个体的减肥方案中的作用尚未得到充分评估。本研究在一个自由选择的超重人群中，考察了能量摄入调整、GI和土豆摄入量的饮食处方对体重减轻、饮食处方依从性、身体成分和血糖控制的影响。
90名超重（体重指数[BMI]为29.6±3.9）的男性和女性被随机分为3组，为期12周。两组被建议每天减少500千卡的能量摄入，并分别食用以低GI或高GI食物为主的饮食（分别为低血糖生成指数能量减少[LGI-ER]或高血糖生成指数能量减少[HGI-ER]饮食）。第三组不接受能量限制、GI规定或营养咨询。所有组均被指示每周食用5-7份土豆。在基线和12周时测定体重、身体成分、葡萄糖耐量和甘油三酯的变化。
各组之间在体重减轻或身体成分变化方面没有显著差异；然而，所有组从第0周到第12周均出现了适度的体重减轻和身体成分变化（p<0.05）。在这种自由生活环境中，实现规定的GI饮食存在明显困难。在治疗组内或治疗组之间，甘油三酯的空腹浓度、葡萄糖耐量、胰岛素或胰岛素敏感性均无显著变化。
结果表明，在自由生活的男性和女性人群中，体重减轻与能量摄入减少有关。土豆摄入量并未导致体重增加，对于自由生活的受试者来说，遵循高GI或低GI饮食处方都很困难，这突出了改变饮食模式的复杂性。
