Energy balance

The doubly labeled water (DLW) method systematically overestimates energy expenditure differences when comparing low-carbohydrate diets to moderate-carbohydrate diets, likely due to isotopic fractionation and biosynthetic fluxes (e.g., de novo lipogenesis) that violate DLW assumptions.

If you are using the Doubly Labeled Water method to prove that low-carb diets burn more calories, be cautious. This study suggests the method may falsely show an increase due to how it handles isotopes during low-carb metabolism. Other rigorous measures (respiratory chambers, body composition changes) did not show this increase. Therefore, claims of a significant metabolic boost from low-carb diets based solely on DLW data may be overstated.