Isolating & Exploiting the Mechanisms That Link Breakfast to Human Health - Acute

Causal links between breakfast consumption, the individual components of energy balance, and health have recently been established and it is now important to examine and target the underlying biological mechanisms involved to maximised potential health benefits. Specifically, the substitution of a portion of carbohydrate for protein at breakfast may enhance the potential health benefits of breakfast through targeting distinct mechanistic pathways. Broadly, introducing a greater protein load at breakfast increases insulin secretion and delays gastric emptying, thereby eliciting a potentiated insulin response. In turn this may therefore improve glucose tolerance during a subsequent meal. Additionally, maintenance of euglycaemia following breakfast consumption, coupled with the thermic effect of feeding protein may accentuate the elevated energy expenditure following breakfast observed in previous studies. Finally, both the physical and chemical properties of protein exert a marked satiating effect. Collectively, these mechanisms could interact to maximise the net impact of breakfast on energy balance and associated health outcomes. However, whilst the evidence indicates obvious benefits of feeding a higher protein dose at breakfast, relatively little research has focused on the response to protein over multiple meals/days. Furthermore, and importantly, the mechanisms involved in the second-meal phenomenon and the potential for initial meals of varied composition to target these mechanisms have never been systematically investigated. To begin investigating the outlined mechanisms healthy, non-obese participants will be recruited to take part a randomised crossover trial that will contrast the acute metabolic responses to a protein-enriched breakfast, with a carbohydrate rich breakfast, and the total omission of breakfast.