"starvation mode"

SeanMurphy

I personally think starvation mode is a myth. [:

I think the body's metabolism can and will readjust to a lower caloric intake, and that can make it harder and harder to lose weight by adjusting diet. However, I also don't think that going under some magical 1200 calorie limit will automatically slam your metabolism down, as some posts seem to indicate. Nor do I think that eating under some limit will cause you to stop being able to burn calories by exercise. Energy is Energy, and if you're expending it, it comes from somewhere. Your body is pretty smart and even if you aren't taking in many calories via food, it will sacrifice fat before anything else, until you have very nearly no fat reserves, and THEN it will attack protein (muscles) and you'll end up in REAL starvation mode, such as we see with folks with anorexia nervosa, with the tell-tale wasting of the muscles, etc.

That said, keeping your metabolism stoked is the quickest way to lose weight. Eating an amount of calories that is less than your daily expenditure through exercise and general resting metabolic activity, but not DRASTICALLY less, is the most efficient path. Drastically less caloric intake, or a "crash diet" would, indeed, make you drop pounds quickly, but only for a short period of time before your metabolism readjusts, and you are too tired and lethargic to actually go out and do the exercise you want and need to do. And since your metabolism has readjusted to this ultra-low intake, if you switch back to your normal intake, you can easily store all that away as your body thinks this is the feast at the end of a famine and wants to store up as much fat energy as it can in preparation for the NEXT famine.

So yes, don't starve yourself on purpose, but don't freak out if mfp tells you you're risking starvation mode occasionally.