How Long for Metabolism to Stabilize after Dieting?

By October 26, 2012

I have a question regarding metabolism. I work out pretty vigorously 6 days a week and eat a minimum number of calories – about 500 less than what the nutrition pyramids say I should. Obviously I’m constantly hungry and irritable, but when I increase my calories, I immediately start putting on weight around my middle! I’ve heard that you can depress your metabolism by constant dieting and exercise, and that you have to let your body “swing” above its natural weight before your metabolism speeds back up and lets you maintain your body’s “natural” weight eating the correct amount of calories. So here’s my question – is this true, and if so, do you have any approximation of the time it takes for someone’s metabolism to stabilize? I’ve been starving and dieting for 10 years and I’m sick of going hungry all the time, but I’m scared that once I start gaining I’ll end up way too heavy and my weight won’t ever come back down. Thanks for any info you can pass along! – J.

Dear J.,

I’m glad you wrote to us! You bring up some important points, a number of which I want to address.

I’ll start with metabolism, since that is the focus of your question. There are two main reasons why your metabolism slows down when you diet. The first is because when calories are scarce, the body protects itself against starvation and slows systems down to conserve energy. The second cause of slowed metabolism is the muscle loss that accompanies inadequate nutrition. When you return to providing enough calories to properly fuel your body and rebuild lost muscle, metabolism does start to return to normal again. In general, under healthy conditions, exercising builds muscle and therefore improves metabolism. But if your body isn’t getting enough fuel for your level of physical activity, muscle will actually end up being broken down—therefore having the opposite effect.

Unfortunately, without doing a full assessment of you and your history, I can’t be any more specific. What you describe as weight gain “in the middle” when you increase calories, could be due to fluid shifts/retention depending on the way you usually eat. It may actually be a healthy return to what is normal for your body. The fact that it happens “immediately” indicates that it is not body fat. It would be helpful if you could consult with a nutritionist in your area to get specific answers. (See “Finding a Nutritionist.”)

What concerns me the most from your e-mail, however, are your fears of gaining too much weight and your life of chronic starving, dieting, hunger, and what I suspect to be over-exercising. I sense that you want to break out of the “Thin Cage,” but are also overwhelmed and afraid. It’s a very positive sign that you now recognize that you are unhappy with living this way. This is your opportunity to take some action and break free!

First, I’d recommend that you read Constance’s book, Life Inside the “Thin Cage.” Secondly, it is vital that you see a therapist who specializes in disordered eating (See “Finding Treatment“). You need someone to help you examine the root of your fears, and guide you to a place of better health and well being. You can be at the healthiest weight for your body type without being hungry, obsessed, tired and afraid. Take steps towards that future now!

With concern,