Whey Protein, Resistance Training, and Changes in Body Composition

• 24 hour energy expenditure and substrate oxidation [ Time Frame: 9 months ] [ Designated as safety issue: No ]
  24hr energy expenditure and substrate oxidation will be measured by whole room indirect calorimetry
• Muscular strength and endurance [ Time Frame: 9 months ] [ Designated as safety issue: No ]
  One rep max strength will be measured on the chest and leg press.
• Resting Metabolic Rate [ Time Frame: 9 months ] [ Designated as safety issue: No ]
  Resting metabolic rate as measured by indirect calorimetry as kcal/day will be evaluated. Also, substrate oxidation (fat and carbohydrate oxidation) will be evaluated.

The objective of this project is to determine the effect of 9 months of progressive resistance training with daily whey protein supplements on the body composition (changes in muscle and fat) in young adults. The investigators hypothesize that those individuals who receive whey protein supplements will have larger gains in muscle and larger losses of fat tissue in response to resistance training compared to those who receive supplements of soy or carbohydrate.

Healthy men and women will be recruited to participate in 9 months of supervised resistance training (3 days/wk) and will be randomized to one of three daily supplement groups: Whey protein, soy protein, or carbohydrate control. Body weight, muscular strength and endurance, and resting blood pressure will be assessed at baseline, 3, 6 and 9 months. Body composition will be assessed at baseline, 3, 5, 7, and 9 months. A sub-sample (N = 17 per group, assessed at baseline and 9 months) will be randomly selected for muscle samples of the upper leg to determine changes in the size of muscle fibers, and chemical factors associated with muscle growth. Blood samples will be obtained from sub-sample participants to assess changes in glucose and fat metabolism, as well as other chemicals likely to promote or inhibit muscle growth. We will also assess changes in daily energy expenditure and the use of fuel to produce energy (carbohydrate, fat, protein) that may result from the intervention. We hypothesize that those individuals who receive whey protein supplements will have larger gains in muscle and larger losses of fat tissue in response to resistance training compared to those who receive supplements of soy or carbohydrate.

• Dietary Supplement: Whey Protein supplement
  40 g/day of whey protein will be consumed in 2 doses for 9 months (Study duration)
• Dietary Supplement: Soy Protein Supplement
  40 g/day of soy protein will be consumed in 2 doses for 9 months (Study duration)
• Dietary Supplement: Carbohydrate supplement
  40 g/day of maltodextrin will be consumed in 2 doses for 9 months (Study duration)

• Experimental: Whey protein supplementation
  Daily whey protein supplementation
  Intervention: Dietary Supplement: Whey Protein supplement
• Experimental: Soy Protein supplementation
  Daily soy protein supplementation
  Intervention: Dietary Supplement: Soy Protein Supplement
• Experimental: Placebo
  Daily carbohydrate placebo supplementation
  Intervention: Dietary Supplement: Carbohydrate supplement

Inclusion Criteria:

• BMI 25-39.9
• must be 18- 30 years old
• sedentary
• no medications
• stable weight for at least 3 months

Exclusion Criteria:

• Tobacco/Drug user
• metabolism altering medication
• gain/lost 10lbs in the last 3 months
• current exerciser