Switching to a low-carb, high-fat diet makes your body burn fat for energy much faster—going from burning 0.50 grams per minute to 1.40 grams per minute in just 5 days—and this effect goes away when you switch back to a high-carb diet.

The study shows that people on low-carb high-fat diets can burn fat at much higher rates (around 1.5-1.9 grams per minute) compared to normal, which supports the claim that these diets increase fat burning. However, the study doesn't specifically test the exact 5-day timeline or what happens when switching back to high-carb diets.