High-protein Weight-loss Diets: Are They Safe and Do They Work? a Review of the Experimental and Epidemiologic Data

Abstract

Recommendations for increased consumption of protein are among the most common approaches of popular or fad diets. This review summarizes the effects of dietary protein on satiety, energy intake, thermogenesis, and weight loss, as well as its effect on a variety of health outcomes in adults. In short-term studies, dietary protein modulates energy intake via the sensation of satiety and increases total energy expenditure by increasing the thermic effect of feeding. Whereas these effects did not contribute to weight and fat loss in those studies in which energy intake was fixed, one ad libitum study does suggest that a high-protein diet results in a greater decrease in energy intake, and therefore greater weight and fat loss. In terms of safety, there is little long-term information on the health effects of high-protein diets. From the available data, however, it is evident that the consumption of protein greater than two to three times the U.S. Recommended Daily Allowance contributes to urinary calcium loss and may, in the long term, predispose to bone loss. Caution with these diets is recommended in those individuals who may be predisposed to nephrolithiasis or kidney disease, and particularly in those with diabetes mellitus.

Effect of calcium and dairy foods in high protein, energy-restricted diets on weight loss and metabolic parameters in overweight adults

“…35,36 Data on the safety of HP diets are scarce. 37 This study demonstrated that weight loss achieved by HP diets has beneficial effects on markers of cardiovascular function, endothelial function, fibrinolytic markers and liver function. CRP (a strong predictor of cardiovascular disease) is lowered following improvements in insulin sensitivity.…”

High-fibre, low-fat diet predicts long-term weight loss and decreased type 2 diabetes risk: the Finnish Diabetes Prevention Study

“…Still another popular, and evidently efficient [22,31] weight-loss approach is to increase protein intake up to 30% of total energy, with a decrease in either fat or carbohydrate. An increase in protein intake may increase patient satisfaction during a low-fat, energy-restricted diet [22] and has been shown to accelerate weight loss [33] and prevent weight regain [34]. In our study we emphasised adequate protein intake (0.8 g/1 kg body weight) but did not advise to increase it more than that.…”

Energy balance and hypothalamic effects of a high-protein/low-carbohydrate diet

“…Diets with varied macronutrient composition are frequently reported to influence total energy intake and long-term changes in body weight [1][2][3][4][5][6][7][8], however the mechanisms by which different macronutrient combinations influence food intake and body weight are unclear. Low carbohydrate, high protein low energy diets have been widely used in weight management programs.…”