A Simple Analogy To Help Understand Metabolism

One of the most convoluted and controversial topics in health is your metabolism and how it adapts to different diets, exercise programs, and lifestyle changes.  A quick browse through the internet reveals all sorts of fitness influencers who claim to know the secret foods that boost or bust your metabolism, the types of exercise that “kill” your metabolism, and the hacks that “stoke your metabolic fire.”  A few hours of searching on google, IG, FB, or X can leave your head spinning.

The other day I was listening to a podcast that provided one of the best analogies to explain metabolic adaptations.

First, A Little Background

Metabolism is treated like a mystery guarded by a secret scroll that only certain academics can access.  The reality is that metabolism is pretty simple.  The definition of metabolism is “the chemical processes occurring within a living cell or organism that are necessary for the maintenance of life.”  In other words, metabolism is the net of all chemical reactions occurring in your body that provide energy to keep you alive.

Energy comes from the calories we consume and the calories that we store around the body in the form of body fat, glycogen, blood glucose, and in desperate situations protein in muscles.  The job of your metabolism is to provide enough energy to keep you alive and support the major components of life.

We tend to think of metabolism only as it refers to weight loss, but the reality is that metabolism is involved in every physiologic process in the body, and it prioritizes the processes necessary to keep you ticking (like your heart beat, digestion, respiration, and movement).

What About Weight Loss?

Yes, weight loss is as simple as calories in vs calories out.  If you are consuming more calories than you are burning, you will gain weight.  If you are consuming less calories than you are burning, you will lose weight.  But if it is that simple, why does it never seem to work that well?  As it turns out, the calories “burned” side of that equation can get a little complicated.  We don’t “burn” as many calories during the day as we think we do.

Let’s Go To A Deserted Island

For the sake of easy math we will say that a person weighs 150 pounds and consumes 2000 calories per day living here in the Chicago suburbs.  This person lives a routine life and maintains 150 pounds day to day.  If they are consuming 2000 calories a day and are maintaining 150 pounds, that means they are also “burning” 2000 calories per day on average.

Now let’s say we transport this person to a deserted island where they have to survive for one year on a ration of 500 calories per day.

Will they lose weight?

Initially, yes of course they will.

Will they continue to lose weight for the entire year until they wither away into nothing?

Of course not.

Early on in this person’s forced diet, they will lose weight rapidly.  Over time, their body and metabolism will adapt to the low calorie count and the weight loss, and will begin to lower the amount of calories the person burns at rest.  This is referred to as the basal metabolic rate and the resting metabolic rate.

500 Calories a day is a severe caloric deficit.  In response to the severe deficit the person’s metabolism will decrease the amount of energy it is utilizing in order to prioritize life sustaining functions (heart beating, digestion, brain activity etc).

To put it simply, in order to survive the harsh environment, the body has adapted and lowered it’s metabolic rate in order to stay alive.  In this hypothetical example, their body has gone from “burning” 2000 calories per day, down to 500 calories per day.


A year has passed, and our person is returned home.   Immediately the person returns to consuming 2000 calories per day, up from 500.

Will the person begin to gain weight again?

Of course.

Will they gain weight forever until they weigh 700 pounds?

Of course not.

Eventually, their weight will plateau back around where it initially started once they settle back into their routine.

So, What Is The Takeaway?

Your body is incredibly adaptable.  Humans have been able to survive harsh climates, droughts, famines, and extreme environments.  In order to survive those conditions, our metabolisms have become incredibly flexible to provide enough energy to the processes that ensure and guarantee life.

Our metabolic rate will lower itself in response to extreme low calorie situations (like harsh elimination diets and high amounts of exercise).  It will also increase expenditure in cases of large caloric intakes (like a kid going crazy during a sugar rush).

Another example of this phenomena is a female experiencing a loss of menstrual cycle during periods of severe dieting or large amounts of exercise.  In extreme cases, women who are exercising too often or restricting calories may lose their menstrual cycle as a result of the metabolism not being able to provide enough energy for reproductive functions.

Have you ever gone on a crash diet only to see the weight come back on as soon as you went back to normal eating?  Or have you tried undertaking an intense exercise regimen and lost some weight, only to find that the weight loss plateaued or even led to weight gain?  Have you ever gotten frustrated when your exercise or diet app estimates you are burning “X” amount of calories per day, yet you are not losing weight?  Maybe you have noticed that while training for a marathon, or undergoing a severely restrictive diet that you have little to no energy and feel fatigued all the time.  All of these can be explained once you understand how much your metabolism can adapt to different situations.

“Weight loss is what occurs during the period of time that your body is adapting to the new environment.”

BWCLP and Metabolism

This is an incredibly complex topic, but is the primary focus of our Be Well Chiropractic Lifestyle Program.  Metabolism is essential not only for understanding the nuance of weight loss, but for healthy again and lifestyle overall.  Keep your eyes peeled as we plan on launching another BWCLP in the near future!