Popular weight-loss diets: from evidence to practice


The increasing number of overweight and obese individuals has become one of the leading public health concerns in many countries around the world. Concomitant with this increase in the prevalence of obesity has been the rise in the number of weight-loss diets, many of which alter macronutrient composition, but with the majority focused on carbohydrate restriction. Low-carbohydrate diets are attractive because they promise rapid weight loss without having to count calories and compromise the consumption of many palatable foods. By contrast, traditional dietary recommendations for weight loss endorse a fat-restricted and calorie-restricted diet high in complex carbohydrates. Evidence indicates that low-carbohydrate diets could be better in terms of short-term weight loss relative to traditional low-fat diets, but little is known about their long-term utility and safety. Diets based on the traditional Mediterranean dietary pattern are becoming increasingly popular because of their healthful benefits, particularly regarding cardiovascular outcomes. Mediterranean diets encourage consumption of a variety of palatable foods, optimizing adherence and sustainability. In this Review we discuss the current evidence on the efficacy of low-fat, low-carbohydrate and Mediterranean dietary patterns for weight loss, their potential mechanisms of action and important clinical considerations.

Key Points

  • Many popular weight-loss diets are available, though for the majority, little is known about their long-term efficacy, safety and ability to improve parameters associated with the risk of cardiovascular disease

  • Traditional recommendations of fat restriction have been shown to have a negligible effect on long-term weight loss and do not offer any benefit in terms of reducing the risk of cardiovascular disease

  • Low-carbohydrate diets promote greater short-term weight loss than low-fat diets by conferring transient negative-energy balance, but long-term studies are needed

  • Traditional Mediterranean dietary patterns have been shown to improve cardiovascular disease risk factors and to reduce the risk of chronic diseases, though their effects on long-term weight control have not been convincingly demonstrated

  • Health-care professionals should encourage weight-loss strategies that are sustainable and beneficial for overall health

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Figure 1: A comparison of popular weight-loss diets by percent macronutrient and saturated fat.
Figure 2: Differences from baseline in body weight by low-fat diet versus usual diet, and age at screening.
Figure 3: Weighted mean differences in weight loss after (A) 6 months and (B) 12 months of follow-up from a meta-analysis21 comparing the effects of ad libitum low-carbohydrate diets versus low-fat energy-restricted diets on weight loss.


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Correspondence to Frank B Hu.

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Malik, V., Hu, F. Popular weight-loss diets: from evidence to practice. Nat Rev Cardiol 4, 34–41 (2007). https://doi.org/10.1038/ncpcardio0726

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