Circadian Misalignment and Energy Balance

Overview

Preliminary findings from the investigators' lab suggest that circadian misalignment, occurring when meals and sleep are mistimed from one another, alters resting state neuronal processing in areas relevant to food reward and interoception; supporting a role of sleep and meal misalignment, on energy balance regulation. No study has been done to disentangle the effects of sleep and meal timing on body weight regulation, independent of sleep duration. This study will provide information to guide messaging related to timing of meals and sleep that can be translated to individuals whose sleep follows unconventional times, such as shift workers and those with jetlag and social jetlag.

The proposed study will test whether the misalignment of eating occasions to the sleep period influences health markers. The goal of the proposed study is to determine whether eating out of synchrony with sleep influences risk of chronic diseases. The proposed study has both mechanistic and translational objectives. First, the investigators will test whether eating late in the day will influence energy balance (hormones, energy expenditure, nutritional intakes). Next, they will observe how misaligned meals, relative to aligned meals, influence behavior. Overweight men and women will be recruited to participate in a 2-phase, crossover study, with constant sleep periods. Phases will only differ in the alignment of meals to the sleep period: aligned = meals starting 1 h after awakening; misaligned = meals starting 5 h after awakening. Mechanistic aims will be addressed from measurements taken after 3 and 14 d of the intervention. The translational aim will be addressed after a 4 wk free-living period following the prescribed meal times for each phase. This proposed study, which will manipulate meal timing, without affecting total sleep time, is important because it will provide information on the mechanism by which circadian misalignment influences health. As such, the proposed study will be a stepping-stone in the establishment of lifestyle recommendations or therapies to personalize chronotype to reduce the risk of chronic diseases.