Low-carb vegan diet reduces weight, greenhouse gas emissions

Vegan and vegetarian diets that are low in carbohydrates reduce body weight as well as improve glycaemic control and blood pressure in individuals with type 2 diabetes (T2D), suggests a study, adding that a plant-based diet shows greater potential decrease in greenhouse gas emissions.

A group of researchers compared the effectiveness of a low-carbohydrate vegan diet with a moderate-carbohydrate vegetarian diet on weight loss and metabolic measures in diabetes. They randomized 164 participants with T2D to advice on either a low-carbohydrate vegan diet (high in canola oil and plant proteins) or a vegetarian therapeutic diet for 3 months, with both diets recommended at 60 percent of caloric requirements.

Additionally, the researchers obtained body weight, fasting blood, blood pressure, and 7-day food records to assess potential greenhouse gas emissions, with tests of cholesterol absorption undertaken at baseline and end of study in 50 participants.

Both low-carbohydrate vegan and vegetarian diets significantly reduced body weight (‒5.9 kg, 95 percent confidence interval [CI], ‒6.5 to ‒5.28 and ‒5.23, 95 percent CI, ‒5.84 to ‒4.62, respectively), glycated haemoglobin (‒0.99 percent, 95 percent CI, ‒1.07 to ‒0.9 and ‒0.88 percent, 95 percent CI, ‒0.97 to ‒0.8), and systolic blood pressure (‒4 mm Hg, 95 percent CI, ‒7 to ‒2 and ‒6 mm Hg, 95 percent CI, ‒8 to ‒3).

The two dietary patterns also resulted in lower potential greenhouse gas emissions. Of note, only potential greenhouse gas emissions showed a significant treatment difference between the two groups (‒0.63 kgCO₂/day, 95 percent CI, ‒0.99 to ‒0.27), favouring the low-carbohydrate vegan diet.