Breakfast consumption (BC) is habitually associated with a healthy lifestyle (e.g., diet and physical activity), reduced adiposity and favourable cardiometabolic health profiles in children, adolescents and adults. Experimental research in adults has shown that breakfast consumption reduces the glycaemic and insulinemic response to lunch when compared with breakfast omission; this has been termed 'the second meal effect'. Further, breakfast consumption may improve exercise performance and increase free-living physical activity energy expenditure in adults. Understanding the postprandial metabolic responses to BC and breakfast omission (BO) in adolescent girls is particularly important, as this population frequently skips breakfast and have low physical activity levels. Yet, adolescent girls may respond differently to adults due to their distinct metabolic profiles, and past research has not targeted this population. The primary aim of this research is to examine whether BC versus BO affects postprandial glycaemic and insulinemic responses to lunch in adolescent girls. Secondly, it aims to examine the lipaemic and substrate oxidation responses during rest, substrate oxidation during an exercise bout performed later in the day, and physical activity enjoyment during the exercise bout.
Breakfast consumption (BC) is frequently associated with a healthy lifestyle, healthy body weight and favourable cardiometabolic health. Research from studies in adults suggests that breakfast skipping causes elevated plasma glucose and insulin concentrations after lunch. However, there is currently no evidence to suggest a similar metabolic response in adolescent girls, a population that frequently skips breakfast. The primary purpose of this study is to examine the effects of BC versus breakfast omission (BO) on metabolic responses after lunch in healthy adolescent girls.