PrOtein and WEight Loss in teenageRs

Effects of Varied Macronutrient Composition on Weight Loss in Obese Adolescents

The aim of the proposed study is to provide important data on weight loss efficacy in overweight and obese adolescents on an isocaloric higher protein diet vs a lower protein diet utilizing the U.S. Department of Agriculture (USDA) MyPlate nutrition guide. The investigators hypothesize that the higher protein diet will result in greater weight loss due to increased satiety and better dietary adherence.

Aim 1 is to test the efficacy of a personalized higher protein weight loss intervention compared to a lower protein intervention which use the USDA MyPlate nutrition guide.

It is hypothesized that participants randomly assigned to the higher protein dietary treatment will lose more weight based on BMI-Z score over 12 weeks compared to participants in the lower dietary protein treatment.

Aim 2 is to test if changes in subjective ratings of appetite differ by dietary treatment (i.e. protein intake).

It is hypothesized that participants in the higher protein intervention will report a decrease in hunger and an increase in fullness compared to participants in the lower protein intervention.

Aim 3 is to test if change in the hexosamine biosynthetic pathway (HBP) measured at the rate limiting step of glutamine fructose-6-phosphate amidotransferase (GFAT) and glycosylation measured as O-linked N-acetylglucosamine (GlcNAc) transferase (OGT) differ by dietary treatment.

It is hypothesized that participants randomly assigned to the higher protein dietary treatment will have decreased change from baseline levels of GFAT and glycosylation (OGT) due to decreased carbohydrate intake compared to the lower protein treatment.

Exploratory Aims: As exploratory aims, the investigators will test if the higher protein or lower protein dietary treatments differentially alter glucose, insulin, cholesterol, and triglycerides (markers of the metabolic syndrome).

Inclusion Criteria:

• Be male or female
• Be between the ages of 12 and 17, inclusive
• Be at or above the 85th BMI percentile (a number calculated from the participants height, weight, sex, and date of birth)
• Be willing to fast for 12 hours prior to clinic study visits 2 and 4
• Be willing to participate in the research study

Exclusion Criteria:

• Health Conditions:
• Has HIV or AIDS
• Has uncontrolled CVD or arrhythmia
• Has Type I or Type II diabetes.
• Is unable or unwilling to complete the study procedures
• Participant may not qualify for this study based on other exclusion criteria not listed. The study coordinator will go over this information in detail.

Medications:

• Diuretics
• Beta-blocker
• Weight loss medications, diet pills
• Anti-inflammatory drugs (corticosteroid/anabolic steroid/NSAID)
• Antipsychotic medications
• Other medications that may affect fluid balance or weight

Lifestyle:

• Plans to move out of the study area within the next 4 months, or plan to be out of the study area for more than 3 weeks during the course of the study.