Glycemic Index and Obesity
Although weight loss can be achieved by
any means of energy restriction, current dietary guidelines have not prevented
weight regain or population-level increases in obesity and overweight.
Many high-carbohydrate, low-fat diets may be counterproductive to weight
control because they markedly increase postprandial hyperglycemia and
hyperinsulinemia. Many high-carbohydrate foods common to Western diets
produce a high glycemic response [high-glycemic-index (GI) foods], promoting
postprandial carbohydrate oxidation at the expense of fat oxidation, thus
altering fuel partitioning in a way that may be conducive to body fat
gain. In contrast, diets based on low-fat foods that produce a low glycemic
response (low-GI foods) may enhance weight control because they promote
satiety, minimize postprandial insulin secretion, and maintain insulin
sensitivity. This hypothesis is supported by several intervention studies
in humans in which energy-restricted diets based on low-GI foods produced
greater weight loss than did equivalent diets based on high-GI foods.
Long-term studies in animal models have also shown that diets based on
high-GI starches promote weight gain, visceral adiposity, and higher concentrations
of lipogenic enzymes than do isoenergetic, macronutrientcontrolled, low-GI-starch
diets. In a study of healthy pregnant women, a high-GI diet was associated
with greater weight at term than was a nutrient-balanced, low-GI diet.
In a study of diet and complications of type 1 diabetes, the GI of the
overall diet was an independent predictor of waist circumference in men.
These findings provide the scientific rationale to justify randomized,
controlled, multicenter intervention studies comparing the effects of
conventional and low-GI diets on weight control.
Source: Brand-Miller JC, Holt SH, Pawlak
DB, McMillan J. Human Nutrition Unit, School of Molecular and Microbial
Biosciences, University of Sydney, NSW, Australia. 2002
Weight Loss News
Theories about how to lose weight, how to reduce obesity and general weight
management are constantly changing along with ideas about which weight
loss diet program is best and so forth. At present, however, a balanced
diet combined with regular exercise remains the favorite weight loss strategy
of most dietitians and weight loss experts. Return to Weight Loss Data
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