“Starvation mode” is the theory that when you cut calories too low, your body thinks that it’s starving and responds by hanging onto any calories it gets instead of burning them. The result: You gain pounds, rather than lose 'em. But is this line of thinking legit—or just a way to keep people from taking drastic measures to lose weight?
Turns out it's a real thing, says Holly F. Lofton, M.D., director of the medical weight management program at the NYU Langone Medical Center.
How It Works
“Starvation mode is an actual biological process," says Lofton. "It occurs when we restrict calories and when bodyweight declines.” Back in the day, when food was scarce, it was a way for our bodies to ensure survival. But in today's diet-obsessed world, it works against anyone trying to lose weight.
Yes, anyone trying to lose weight. Even a totally healthy eating plan will result in some degree of metabolic adaptation or adaptive thermogenesis (two scientific terms for starvation mode). In fact, a comprehensive review published in the International Journal of Obesity explains that losing just 10 percent of your body weight results in a 20 to 25 percent dip in your daily caloric burn. Argh.
Metabolic adaptation is a normal process—it takes place when the body uses a blend of hormones, neurotransmitters, proteins, and other chemical messengers to regulate how many calories you burn doing things like breathing, walking, talking, and sweating it out in the gym each day, Lofton says. But when you start eating fewer calories or losing weight, the brain’s hypothalamus and pituitary gland work with other endocrine glands throughout the body to retain calories so you still have enough energy to function properly.
The big issue occurs when your caloric intake is way too low, says Lofton.
How to Avoid the Metabolism Plunge
Truth: Your metabolism will slow some if you cut 500 calories per day, but it will slow a hell of a lot more if you cut 750 or 1,000 calories from your daily menu.
“I don’t suggest women take their caloric intake below 1,200 calories per day,” she says. “At that point women can experience hair loss, a drop in body temperature, extreme fatigue, and other adverse symptoms because the body drastically slows its metabolic processes.”
Luckily, there are a few easy ways to prevent starvation mode from interfering with a perfectly reasonable weight-loss plan. Increasing your protein intake can help your body preserve muscle, which stokes your metabolic furnace, to prevent huge dips in calorie-burning potential, says Lofton. Research in the American Journal of Clinical Nutrition suggests that eating 25 to 30 grams of protein at every meal is key to preserving your muscles and metabolism when losing weight.
A regular strength-training routine can also help you maintain and build muscle as you lose weight. Because what good is weight loss if it comes with a crappy metabolism and regain?