Can you "Break" your Metabolism?
- DiscoverPT
- Dec 13, 2023
- 3 min read
Metabolism is the chemical process in which our bodies convert food into energy.
The claim: Calorie restriction and improper diet have RUINED your metabolism.
I know you've seen the ads. "The reason you can't lose weight is because your metabolism is broken!" Then you think to yourself, it's all my fault. I was doing it all wrong!
Advertisors pray on negative thoughts to drum up a problem that requires "fixing". But fear not, it just so happens that the same advertisors have a mysterious new product from the rainforest that can "cure" your new found ailment.
The goal of this article is not to harp on these companies but to demystify some of these claims. This leads us with the question that brought you here: "Can your metabolism actually break"?
#1 What is Metabolism
Metabolism is composed of the chemical process your body uses to convert food into energy. We measure metabolism by your body's ability to utilize energy throughout your daily processes. A calorie is a unit of measure used to quantify metabolism. Therefore, if you maintain your body composition, your calories in will equal calories out.
Some influencers will claim that not all calories are created equal. This is a misnomer. Because calories are all measured using the same quantifiable unit, then they have to equal the same amount of energy. It's like saying a pound of flour weighs more than a pound of feathers. Do you see the confusion? The reality is that the 3 macronutrients are stored and accessed in different ways depending on various factors.
#2 Total Daily Energy Expenditure
Total energy expenditure is the amount of energy you need to complete all of your daily activities.
It is comprised of exercise (5-10%), thermic effect of digestion TEF (15%), non-exercise activity/thermogenisis NEAT (20%), and basal metabolic rate BMR (60%).
Exercise comprises very little of this graphic because we tend to spend a small amount of our time burning energy. So, it may not be the best way to burn calories directly. However, exercise is vital in increasing longevity and will protect you from all-cause death.
Check out my article: Exercise Prescription for a Long Life
TEF is utilized during food digestion. NEAT encompasses daily activities including walking, cleaning, typing, etc. Your basal metabolic rate includes process that keep you alive during sleep, breathing, etc.
#3 Metabolic Adaptation
Alright, we're finally to the good stuff. Can you "break" your metabolism? The notion that your metabolism "breaks" comes from a known process called metabolic adaptation.
Basically, if you reduce your caloric intake too dramatically, then your metabolism may slow down. More specifically, this is commonly known as caloric restriction metabolic adaptation.
As you lose weight, you will inherently require less calories. This is true, however, even when this is taken into account, metabolic slowing can still occur. We are not completely sure how this occurs but most research points to hormonal changes and cellular downregulation.
This process would be vital in pre-historic times when food was scarce.
#4 How big of a factor is metabolic adaptation?
In 2022, a large systematic review was performed by the National Institute of Health that looked at the extent of metabolic adaptation. Even though this is considered high level evidence, we need more data to improve the sensitivity of these findings. There is just too much metabolic variability between individuals.
Over a 3 month period, the scientists found that a 25% daily caloric restriction led to an 8% metabolic adaptation.
Example:
Let's say I want to lose weight and I calulate that I require 2,500 calories/day to maintain body composition/weight (maintenance calories). I decide that I will reduce my caloric intake by 25%. This means that I will eat 1,870 calories over the course of 3 months. After those 3 months, my body may experience metabolic adaptation up to 8%. So, my new maintenance calories would go down to 2,300 calories/day. Instead of losing 625 calories/day, I woud be losing 425.
#5 Can you "break" your metabolism?
Will metabolic adaptation "ruin" your diet? The answer is no. Is it important to understand that your body adapts to the situations you put it under? Yes. The CDC and NIH recommend a 500-1,000 calorie deficit per day. However, it may be more beneficial to start at the lower end in order to evaluate your body's response to a reduciton in calories.
Caloric restriction on its own can also be tricky due to the human condition. Cornell University performed a large study that found that healthy people underestimate calorie intake by 20%. Overweight individuals underestimate calorie intake by up to 40%. That's why it may be more beneficial to make a more wholistic approach that includes changing daily habits, counting calories, and exercise utilization.
If so, this article may be for you:
If you need consultation with your health journey, visit us at:
Find us on Facebook:
Comments