Katherine Chivers
Does bulimia in the long term change your metabolism? Does it get slower?
Updated: Aug 16, 2022
Metabolism is the rate in which your body converts what you eat and drink into energy. During this process, the calories from your food and drink that you consume are combined with oxygen and they release energy that your body needs to function.

Your resting metabolism, which is referred to as your BMR or your basal metabolic rate, is the metabolism that your body needs to do basic functions like breathing, circulating blood, adjusting hormones, growing and repairing cells. These are all the things that your body needs to do just to survive, and your BMR is impacted by all sorts of things. The three main things being:
Your body size and composition - if you are larger, you have a higher BMR because you need more calories to pump blood through your body, for example, and also if you've got more muscle mass - which men typically have more muscle than women, well muscle burns more calories - so then you'll have a higher BMR as well.
Your sex - again, men have usually have a higher metabolism and one of the main reasons is because genetically men generally have more muscle than a female.
Your age - generally muscle tends to decrease as we age and fat accounts for more of our body composition - so that slows down our calorie burning because muscle burns more calories.
Other things that impact how many calories you burn, outside of your BMR, are things like a) food processing - digesting, absorbing, transporting, and storing food in your body, and also b) the amount of physical activity that you do. So that might be exercise like running, walking, tennis, volleyball, football, whatever it is that you do. But also included would be just general things like walking to the shops, walking around your house, yoga - even reading a book burns more calories than watching TV! So basically any general activity that you do, contributes to additional calories that you burn outside of your BMR.
When you've got bulimia, typically you are bingeing and then purging, and unless you eat normally outside of this is as I used to, then because your food intake is less over time, your body doesn't have enough energy to keep up its life sustaining processes - things like pumping blood through your body, breathing, growing, and repairing your cells. So your body needs to adapt to this lower food intake. And over time, your body will actually limit the amount of energy it uses to support only the functions that are absolutely necessary to maintain life. So ultimately your body will require less energy to perform these required functions, which results then in a decreased basil metabolic rate, your BMR, your metabolism. The same goes for if your method of purging is over-exercising, your body is still needing to adjust and it's trying to limit the amount of energy it's using so it can continue with its basic life functions because you are using all of its energy by over-exercising. So what it's got left, it actually needs to sustain itself and to just try and keep living. Therefore your metabolic rate will decrease because it's got less energy to use to sustain these functions.
But back to the question - does bulimia in the long term change your metabolism, does it get slower? So the answer is, yes, it can impact your metabolism. It will often impact your metabolism. However, the body is very smart, once you resume regular and consistent eating again, then your body will again adapt to having all of those extra calories again, which it then can use for energy to perform all those life giving functions. It will gradually learn that it doesn't need to limit its energy use anymore. So over time, your BMR will gradually start to rise again because your body's starting to get used to having excess calories again, which means that it has excess energy again so it doesn't need to conserve energy.
So yes, it can impact your metabolism, but no, it doesn't have to be permanent. So the desired changes won't happen overnight, but if you stay confident, consistent and committed to regular eating without purging for at least three months, then see how your metabolism improves.
Trust your body, trust that it know what its doing - nourish it and and care for it - it’s your home for this life and the only one you’ve got!