Researchers from Laval University (Quebec City) reviewed all the literature on protein and fat loss and concluded that following a high-protein diet does in fact increase fat loss. This may be due to the fact that high-protein diets increase metabolic rate and decrease hunger.
They also concluded that dairy proteins, such as whey and casein, are best for building muscle, yet the kind of protein consumed, plant or animal, had no effect on fat loss.
The take- home point here is to eat 1–1.5 grams of protein per pound of bodyweight each day from a variety of protein sources, such as lean beef, poultry, eggs, fish and dairy. Be sure to use whey and casein protein powders to enhance muscle growth, as well as aid fat loss.
REFERENCE: J-A Gilbert et al., “Effect of proteins from different sources on body composition,” Nutrition, Metabolism & Cardiovascular Diseases, in press, 2011.