Current nutritional research indicates the quality of macronutrients matters more than macronutrient proportion

The consumption of certain types of macronutrients above all else in food decision is often strongly emphasized in diet plans. For years, the US govenment advocated low-fat diets. When obesity rates continued to increase despite an increase in national carbohydrate consumption, part of the backlash resulted in the popularity of low carb / high fat diets (i.e. Atkins, South Beach, Ketogenic etc.) As shown below, national consumption of macronutrients has not changed much since the late 80s. In the same time period, obesity rates have risen from 23% to 38%.

But what does the evidence on macronutrient proportion say?

  • A 2015 meta-analysis of 53 randomized control trials concluded their findings suggest that "the long-term effect of low-fat diet intervention on bodyweight depends on the intensity of the intervention in the comparison group. When compared with dietary interventions of similar intensity, evidence from RCTs does not support low-fat diets over other dietary interventions for long-term weight loss" [1].
  • A 2014 meta-analysis of 48 unique randomized control trials concluded "Significant weight loss was observed with any low-carbohydrate or low-fat diet. Weight loss differences between individual named diets were small. This supports the practice of recommending any diet that a patient will adhere to in order to lose weight" [2].
  • A separate 2014 meta-analysis of 19 randomized control trials comparing low carb and balanced diet approaches concluded "Trials show weight loss in the short-term irrespective of whether the diet is low CHO or balanced. There is probably little or no difference in weight loss and changes in cardiovascular risk factors up to two years of follow-up when overweight and obese adults, with or without type 2 diabetes, are randomised to low CHO diets and isoenergetic balanced weight loss diets" [3].

"When people eat controlled diets in laboratory studies, the percentage of calories from fat, protein, and carbohydrate do not seem to matter for weight loss. In studies where people can freely choose what they eat, there may be some benefits to a higher protein, lower carbohydrate approach. For chronic disease prevention, though, the quality and food sources of these nutrients matters more than their relative quantity in the diet. And the latest research suggests that the same diet quality message applies for weight control."

Beyond Willpower: Diet Quality and Quantity Matter by Harvard School of Public Health

Harvard School of Public Health advocates emphasizing caloric quality over profile of macronutrients consumed and the name of our website comes from this recommendation.

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