Effective strategies for reducing food intake are needed to reduce risk of obesity-related cancers. We investigated the effect of low and high glycemic load (GL) diets on satiety and whether satiety varied by body mass index (BMI), gender, and serum leptin. Eighty normal weight (BMI = 18.5-24.9 kg/m²) and overweight/ obese (BMI = 28.0-40.0 kg/m²) adults participated in a randomized, crossover controlled feeding study testing low GL vs. high GL diets. The 28-day diets were isocaloric with identical macronutrient distributions, differing only in GL and fiber. Participants completed visual analog satiety surveys and fasting serum leptin after each 28-day period. T-tests compared mean within- and between-person satiety scores and leptin values. Participants reported 7% greater satiation on the low GL vs. the high GL diet (P = 0.03) and fewer food cravings on the low GL vs. the high GL diet (P < 0.001). Compared to males, females reported less hunger (P = 0.05) and more satiety on the low GL vs. the high GL diet (P < 0.01). Participants with low body fat (<25.0% for men; <32.0% for women) and BMI <25.0 kg/m² reported study food was tastier on the low GL vs. the high GL diet (P = 0.04 and P = 0.05, respectively). In summary, reducing GL, and/or increasing fiber, may be an effective way to lower calories consumed, improve energy balance, and ultimately reduce cancer risk.
Trial registration: ClinicalTrials.gov NCT00622661.