Meal size, timing, and postprandial outcomes

What are we doing? Experimental meal challenges are often conducted in the morning using a fixed caloric challenge (i.e., 1000 kcal of pie, a 75g OGTT, etc.). This does not account for the inter-individual differences in metabolic needs due to variations in resting metabolic rate, activity level, etc. Further, these fixed challenges may present an increased challenge for individuals with an evening chronotype (i.e., people who are most alert later in the day) compared to their morning chronotype counterparts. This study has two aims. Aim 1 examines the effect of eucaloric (calories for one meal based on RMR) vs. hypercaloric (+50% calories) mixed meals on postprandial metabolic, vascular, and hemodynamic outcomes. Aim 2 examines differences in the same outcomes during morning or evening feeding (each preceded by a 10-hour fast) and will explore potential variations in these responses based on chronotype.