Low carbohydrate and very low fat diets may increase metabolic demands by requiring the body to synthesize glucose or fatty acids.

“so if you're not eating much carbohydrate your body has to work a little bit harder to synthesize glucose for example so there are some physiological ways in which you're kind of increasing the demands a little bit metabolic demands same with very low um fat diets you're slightly increasing metabolic demands you have to synthesize you're going to synthesize more fatty acids and um”