Metabolic Responses to Breakfast in Adolescent Girls
Condition: Postprandial Hyperglycemia
MeSH terms: Hyperglycemia
Study type: Interventional

Summary: 
      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.
    

Detailed description: 
      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.
    

Intervention name(s): Breakfast consumption; Breakfast Omission
Intervention type(s): Other; Other
Intervention description(s): Consumption of breakfast: The breakfast provided was designed based on the "characteristics of an ideal breakfast" outlined in Giovannini et al., (2008). The breakfast provided in the present study will include the following: all-bran cereals (Kellogg's), semi-skimmed milk (Tesco), Royal Gala Apple (Tesco) and Orange Juice from Concentrate (Tesco) containing the amount of carbohydrates usually consumed at breakfast in the UK (Reeves et al., 2013). The portion for each participant will contain 0.06 g of carbohydrate per kcal of measured RMR. As the portion size (20% of daily calorie intake) will be calculated based on individual RMR , no leftovers will be allowed.; Omission of breakfast. Participants will consume water within 15 min, the individual volume of which will be calculated based on the liquid content of the breakfast [milk (ml)+ orange juice (ml)].
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Two experimental trials will be completed in a randomised counterbalanced order: BC and BO. A standardised lunch will be provided three hours after breakfast consumption (BC) or after water consumption during breakfast omission (BO). Finger prick blood samples for the analysis of plasma glucose, insulin and triaclglycerol and expired gas samples for the analysis of substrate oxidation will be taken throughout the trials. An incremental cycling exercise test with 4 minute stages will be performed 2 h after lunch for the determination of maximum fat oxidation (MFO) and intensity at which MFO occurred (i.e., Fatmax). The OMNI scale will be used to evaluate the perceived exertion at the end of each cycling stage. PA enjoyment will be evaluated using Physical Activity Enjoyment Scale (PACES).
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: cardiovascular disease; diabetes