The Myth of ‘Starvation Mode’
I’ve started using MyFitnessPal and was intrigued by the suggestion by that app that very low caloric intake would induce something called “starvation mode”. I’m familiar with much of the scientific evidence regarding various diets, and I’ve never encountered this particular term in the scientific literature.
I Googled “starvation mode” and was astounded by the amount of misinformation out there. The basic idea is that a starved body will undergo a metabolic adaptation to conserve energy and thus prevent weight loss or even cause weight gain despite an extremely low caloric intake.
Look at any group of people who have literally starved over a long period of time, and you will not find any obesity. Some of those people may have a hormone problem of one sort or another (eg, underactive thyroid), and all have undergone metabolic adaptation to starvation, but none are able to pull off the miracle of obtaining or maintaining body fat despite a lack of adequate caloric intake.
In fact, patients who undergo weight loss surgery are routinely expected to endure what MyFitnessPal calls “starvation mode”. It’s part of the plan. Of course, they are closely monitored medically in order to ensure adequate nutrition (including vitamins/minerals) and monitor for known risks (eg, gallstones). There are risks associated with a very low calorie diet, and those risks must be weighed against benefits. Without a doubt, such a diet would be very harmful to a normal or underweight individual and should only be considered by a very overweight/obese individual (with proper medical supervision).
Here is a great post by a layperson about “starvation mode”: http://fattyfightsback.blogspot.com/2009/03/mtyhbusters-starvation-mode.html. In plain terms, the author explains that while there is some underlying truth to the concept (ie, the body does adapt to low caloric intake and weight loss by reducing resting energy expenditure), the common conception of “starvation mode” is a myth.
