Whey or Casein Protein May Boost Energy Expenditure, Fat Oxidation When Taken Before Exercise
A recent study suggests that consuming whey or casein protein before running on a treadmill may result in higher post exercise energy expenditure, which is related to fat oxidation and weight loss. Fat oxidation refers to the ability to burn fat and use fat instead of carbohydrate as a fuel.
Participants in the study included 11 healthy, recreationally active college-aged men. In order to be included in the study, they were required to ingest no more than 300 mg of caffeine per day and to abstain from any nutritional supplementation other than protein and multi-vitamins for 30 days before the beginning of the study.
All of the participants ingested one of four things: 25 mg whey protein isolate; 25 mg casein protein; 25 mg maltodextrin; or a non-caloric control. After ingesting their supplement, they completed 30 minutes of treadmill exercise protocols at 55-60% heart reserve rate. Substrate oxidation and energy expenditure were assessed at baseline, during exercise, and 15 minutes after exercise.
The researchers found that the men who ingested 25 g of whey protein isolate or 25 g of casein protein 30 minutes before moderate-intensity treadmill exercise had higher post-exercise energy expenditure than that those ingested the maltodextrin or the control. Specifically, resting energy expenditure was 3.41kcal/kg for the whey protein, 3.39 kcal/kg for those the casein protein, compared to 1.57 kcal/kg for the maltodextrin and 2.00 kcal/kg for the control. They also found that significantly more fat was oxidized in the casein group than in the whey group, 2.28 g and 1.7 g respectively.
Researchers from Texas Woman’s University led the study. It was published on November 29, 2018, in the Journal of the International Society of Sports Nutrition.
Whey protein is one of the two proteins found in milk but is only approximately 1% of the composition of milk. It is obtained as a byproduct of cheese making and can be purchased in powder form from health food stores. Additionally, it can be found in yogurt and in ricotta cheese, which is one of the only cheeses that do not have the whey removed. Casein is the other protein that can be found in milk