The study by researchers at McMaster University and just published in the American Journal of Clinical Nutrition, was conducted by the Department of Kinesiology's Exercise Metabolism Research Group, lead by Stuart Phillips.
The researchers took three groups of young men 18 to 30 years of age -- 56 in total -- and put them through a rigorous, five-day-per-week weightlifting program over a 12-week period. Following their workouts, study participants drank either two cups of skim milk, a soy beverage with equivalent amounts of protein and energy, or a carbohydrate beverage with an equivalent amount of energy, which was roughly the same as drinking 600 to 700 milliliters of a typical sports drink.
Upon the study's conclusion, researchers found that the milk drinking group had lost nearly twice as much fat - two pounds - while the carbohydrate beverage group lost one pound of fat. Those drinking soy lost no fat. At the same time, the gain in muscle was much greater among the milk drinkers than either the soy or carbohydrate beverage study participants."The loss of fat mass, while expected, was much larger than we thought it would be," says Phillips, associate professor of kinesiology at McMaster. "I think the practical implications of these results are obvious: if you want to gain muscle and lose fat as a result of working out, drink milk."
As reported in the first phase of the study, the milk drinking group came out on top in terms of muscle gain with an estimated 40 per cent or 2.5 pounds more muscle mass than the soy beverage drinkers. In addition, this group gained 63 per cent or 3.3 pounds, more muscle mass than the carbohydrate beverage drinkers.
"I think the evidence is beginning to mount," says Phillips. "Milk may be best known for its calcium content in supporting bone health, but our research, and that of others, continually supports milk's ability to aid in muscle growth and also promote body fat loss. To my mind -- with milk being a source of nine essential nutrients -- it's a no brainer: milk is the ideal post-workout drink for recreational exercisers and athletes alike."
Ongoing work with this project will focus on the components of milk that might be responsible for the effects observed by the McMaster-based researchers. The work was supported by grants from the Canadian Institutes for Health Research and a grant from the US National Dairy Council.