All that matters for weight loss (and weight gain) is calories in and calories out (CICO). All of the "special" diets that people propose work on this principl

All that matters for weight loss (and weight gain) is calories in and calories out (CICO). All of the "special" diets that people propose work on this principle. They simply take different approaches to try to make "eating less" easier. Certain foods make you feel fuller than others, so some people have success changing their diets to include more of those foods. Other people have success just eating less of what they eat now without changing their diet. As far as I know, the keto diet is designed to treat epilepsy in children. There is no current scientific consensus that keto helps with weight loss compared to any other diet with a similar CICO. I'm sure people are researching it right now so that could change, but we know enough about how the laws of physics and the human body work to know that whatever is happening, CICO is the basis of it.