The Beneficial Effects of a Protein-rich Breakfast on Appetite Control & Cognition in Overweight and Obese Adolescents

• Perceived Appetite and Satiety [ Time Frame: 5 weeks ] [ Designated as safety issue: No ]
  Questionnaires, assessing appetite sensations (i.e., hunger, fullness, prospective food consumption, motivation to eat), hedonic ratings (pleasure), and palatability will be completed throughout each of the testing days (which are separated by 2 weeks). The questionnaires contain validated visual analog scales (VAS) incorporating a 100 mm horizontal line rating scale for each response. The questions are worded in the following manner "how strong is your feeling of" with anchors of "not all" to "extremely."
  
  
• Appetite and Satiety Hormones (i.e., Ghrelin, PYY) [ Time Frame: 5 weeks ] [ Designated as safety issue: No ]
  25 total blood samples will be drawn throughout each of the testing days (which are separated by 2 weeks). Specifically, there will be 5 ml/sample; 125 ml (4.2 oz)/testing day. The samples will be collected in test tubes containing EDTA (ethylenediaminetetraacetic acid). Protease inhibitors will be added to the sample to reduce protein degradation. Samples will be centrifuged at -4°C for 15 minutes. The plasma will then be separated and stored in microcentrifuge tubes at -80°C for future analysis. Plasma total ghrelin and total PYY will be measure.
  
  
• Functional Magnetic Resonance Imaging (fMRI) Brain Activation Responses [ Time Frame: 5 weeks ] [ Designated as safety issue: No ]
  Brain activation responses will be assessed prior to dinner in each of the 3 testing days (separated by 2 weeks). During the fMRI brain scan procedure, the participants will focus on a set of photographs which will be projected onto a screen and easily viewed through a mirror. The fMRI paradigm incorporates stimuli from three categories of pictures including food, nonfood (animals), and blurred baseline images. Brain activation in the Insula, Amygdala, Hippocampus, and Parahippocampus will be examined when viewing food vs. animal pictures.
  
  

• Daily Energy Intake [ Time Frame: 5 weeks ] [ Designated as safety issue: No ]
  Energy intake during breakfast, lunch, dinner, and evening snacks of each testing day will be measured.
  
  

Breakfast skipping, which is a common, yet unhealthy dietary habit among young women, has been strongly associated with over-eating (especially in the evening), weight gain, and obesity. Breakfast skipping has also been shown to reduce cognitive function in this population. However, it is unclear as to whether the addition of breakfast, with specific emphasis on increased dietary protein, leads to improvements in these outcomes. This study will provide mechanistic evidence supporting the addition of a protein-rich breakfast to improve and/or re-establish appetite control, energy intake regulation, and cognitive function in overweight/obese 'breakfast skipping' young women. 25 overweight and obese 'breakfast skipping' adolescent girls will participate in the following randomized within-subject crossover-design breakfast study. The participants will randomly complete the follow breakfast patterns at home for 6 days: 1) Breakfast Skipping; 2) Consumption of Normal Protein breakfast meals(i.e., 350 kcal; 15% of the meal as protein, 65% CHO, & 20% fat); and 3) Consumption of Protein-Rich breakfast meals (i.e., 350 kcal; 40% of the meal as protein, 40% CHO, & 20% fat). On the 7th day of each pattern, the participants will report to the MU-Brain Imaging Center in the morning to complete the respective 10-h testing day. The participants will begin the testing day by either skipping breakfast or consuming their respective breakfast meal. Blood samples and assessments of perceived appetite, pleasure/reward, and cognitive function will be collected/completed at specific times throughout the day. A standardized lunch will also be provided. Prior to dinner, a brain scan will be completed using functional magnetic resonance imaging (fMRI) to identify brain activation patterns in response to food pictures. Following the fMRI, the participants will be provided with an ad libitum dinner buffet to consume of the facility. They will also be given evening snacks to consume ad libitum, at home throughout the remainder of the day. There is a 7-day washout period between each breakfast pattern. Primary outcomes include morning, mid-day, afternoon, and evening appetite, satiety, pleasure/reward, hormonal responses (plasma glucose, insulin, ghrelin, and PYY concentrations), brain activation patterns, evening energy intake, and daily energy intake.