Dietary Fiber and Weight Gain

KEYWORDS:
• dietary fiber
• obesity
• weight gain

To the Editor: The study by Dr Ludwig and colleagues¹ provides evidence that a high intake of low-fiber foods is a key mediator of the epidemic of obesity in the United States. The authors plausibly suggest that this effect is primarily attributable to the often high glycemic index of such foods. A secondary but no less intriguing finding of their study is that increased protein intake is linked to weight gain. The 2 findings may share a common mechanism.

Although dietary protein, administered alone, has a relatively modest impact on insulin secretion, it can markedly potentiate the insulin response to coingested starch.² Remer et al³ reported that when 32 g/d of egg protein was added to a low-protein lactovegetarian diet, the level of C peptide in 24-hour urine, thought to be roughly proportional to diurnal insulin secretion, increased by 60%. Another study compared the bariatric effects of …