Inter-individual variability in response to dietary and exercise interventions as indicators of metabolic disease risk

Background: Clinical disease diagnosis for metabolic disorders using standard reference ranges do not provide the opportunity for personalizing nutritional and medical advocacy, since they lack the ability to identify at-risk individuals with high finesse. Objectives: To identify individuals/subgroups among a sample that display metabolic profiles with latent inclination towards higher chronic disease risk using meal challenge tests or exercise intervention regimes. Methods: Postprandial responses to high and low glycemic index meals were used to identify variability in the adipoinsular axis, as an indication of higher risk for insulin resistance in healthy, overweight premenopausal women. In a second study healthy, perimenopausal women performed 270 mins of aerobic exercise each week for 6 months. Baseline and 6 month measures of weight loss, change in body fat%, and compliance to the exercise regimen were measured. A third study evaluated the fasting and postprandial glycemic and lipemic response to a standard meal in healthy premenopausal women during the luteal and follicular phases of their menstrual cycle. Results: GI meal challenges identified a subset of the population to demonstrate high postprandial leptin response group in the low GI compared to the high GI, in addition to another subset that displayed a normoglycemic, yet hyperinsulinemic response to the lowGI compared to the high GI meal. The latter group was identified to likely be at higher risk for insulin resistance. The exercise regimen in perimenopausal women indicated that women that recorded between 80-100% compliance had the highest reduction in body fat%, and a non-significant, but higher raise in insulin sensitivity as a result of the regimen. Body fat distribution was also associated with different insulin sensitivities as measured by the Matsuda index between the two menstrual cycle phases - with the luteal phase and the follicular phase showing highly variable responses in women. Conclusions: Meal challenges, and exercise intervention regimes could be effective screening tools to identify successful personalized nutrition programs in clinical settings.