Protein-rich diets are surging in popularity for
weight loss. An increase in diet-induced thermogenesis, better preservation of fat-free mass, and enhanced satiety with greater
dietary protein intakes may lead to increased energy expenditure and decreased energy intake; and thus promote a more negative energy balance that facilitates
weight loss. Results from large randomized trials and meta-analyses of many smaller trials indicate that
high-protein diets typically induce significantly greater amounts of
weight loss than conventional low-fat or high-
carbohydrate diets during the early, rapid
weight loss phase (3-6 months), but differences between diets are attenuated and no longer significant during the late, slow
weight loss phase (12-24 months). Gradually decreasing adherence may be responsible for this observation; in fact, dietary adherence, rather than macronutrient composition, is likely the major predictor of long-term
weight loss success. Recently, some randomized trials evaluated the efficacy of high-
protein (vs. normal-
protein) diets consumed ad libitum during
weight loss maintenance, i.e. after clinically significant
weight loss. Weight regain may be smaller with
high-protein diets in the short-term (3-12 months), but longer studies are needed to confirm this. Given the lack of conclusive evidence in favor of
high-protein diets, or any other dietary pattern, it is reasonable to conclude that no individual nutrient is a friend or a foe when it comes to
weight loss and its maintenance. Therefore, any diet that best suits one's dietary habits and food preferences is likely to be better adhered to, and thus lead to more successful long-term
weight loss.