Do you have a source for that? First, I'm talking about actual weight loss, not fat loss. They are two different goals. Weightlifting causes muscle damage tha

Do you have a source for that? First, I'm talking about actual weight loss, not fat loss. They are two different goals. Weightlifting causes muscle damage that needs repairing. This requires energy. Intermittent fasting will cause longer repair times and if done incorrectly will cause muscle loss. (muscle bulk I assume is your end goal, as opposed to a specific need for a sport) However the common way to gain muscles is to take protein powder laced with hormones, natural or otherwise. As a strategy for weight loss it is useless unless you exercise enough to burn off the extra calories consumed. This requires time and effort, both of which are difficult. Loosing fat is not in its self weight loss.