Low-carbohydrate and balanced-carbohydrate weight-reducing diets produce little to no difference in average weight loss over one to two years in overweight and obese adults without type 2 diabetes, with a mean difference of 0.93 kg (95% CI: -1.81 to -0.04) based on 14 randomized trials involving 1,805 participants.

When people eat fewer carbohydrates, their bodies produce fewer insulin signals, which causes fat cells to release stored fat and the liver to convert that fat into ketones. These ketones reduce hunger, so people eat less without trying. At the same time, the body starts burning fat for energy instead of sugar. Whether someone eats very few carbs or a moderate amount, the result is the same: they take in fewer calories than they burn, and their body loses weight by using stored fat. The amount of carbs doesn't change this outcome because both diets lead to the same energy deficit over time.