A new study from McMaster University in Ontario, Canada, just proved that the Holy Grail of Fitness—losing fat while you build muscle—is possible. The bad news is it’s really hard. Researchers took two groups of young fit men and put them on strict meal plans for four weeks (all calories were carefully controlled throughout the study) that totaled 40 percent fewer calories than they needed to maintain their bodyweight. One group received a high-protein diet (about one gram per pound of bodyweight), and the other group was given half that amount of protein.
All subjects performed four days of intense weight training and two days of high-intensity interval sprint training each week. After four weeks, the results were pretty amazing. The low-protein group lost almost eight pounds of body fat. The high-protein group lost approximately 10 pounds of body fat and added two pounds of muscle. Most surprisingly, both groups lost very little muscle. While these changes are impressive, especially considering the four-week window, the lead researchers admit that the subjects were pretty miserable, and by the end of the experiment all the subjects could talk about was their own hunger.