The acute effects of dietary protein at breakfast on reward driven neural activity prior to lunch

Abstract

Although numerous studies have targeted the physiological, homeostatic signals altered with various dietary interventions, data are limited concerning whether the non-homeostatic, reward-driven mechanisms underlying ingestive behavior are modulated. The study purpose was to determine whether breakfast consumption would modulate the neural activity in brain regions associated with reward-driven eating in overweight `breakfast skipping' (BS) adolescent girls and to identify whether increased protein at breakfast leads to additional alterations. Ten girls (Age: 15±1y; BMI percentile 93±1%; BS 5±1x/week) completed 3 testing days. Following the BS day, the participants were provided with, in randomized order, normal protein (NP; 18±1g protein) or higher protein (HP; 50±1g protein) breakfast meals to consume at home for six days. On day 7 of each pattern, the participants came to the laboratory to consume their respective breakfast followed by pre-lunch (i.e., 3-h post-breakfast) appetite questionnaires and a functional magnetic resonance imaging (fMRI) brain scan to identify brain activation responses to viewing food vs. non-food images. Breakfast consumption led to reduced hippocampus and parahippocampus activation and increased medial frontal gyrus activation vs. BS. Between breakfast meals, HP resulted in reduced insula activation vs. NP. Parahippocampal and insula activations were correlated with appetite; insula activation was inversely correlated with satiety. Collectively, the incorporation of breakfast led to alterations in brain activation involved with reward-driven eating behavior with additional alterations following the protein-rich meal. These data suggest that increased dietary protein at breakfast might be a beneficial, modest strategy to reduce the impact of the modern food environment in overweight `breakfast skipping' adolescent girls.