The idea of your body composition having a "set weight" is some kind of diet lore.
I remember hearing about it in the eighties, so it goes back at least that far.
The theory goes like this, if you lose too much weight too quickly your body will fight back by slowing down your metabolism, making you hungry and storing more fat.
If you google "set weight" you will see all sorts of articles that tell you that if you restrict your calorie intake your body will slow your metabolism so that you gain the weight back - back up to your "set weight."
And there are lots of stories - some true - about how this happened to "crash" dieters.
There's a certain truth to caloric restriction resulting in metabolic slowing, but - to me - there is a glaring flaw in the logic of all this.
If your body has a set weight that it loves so much, how come it's easy to get fatter and stay fatter and hard to get thin and stay thin? Is this theory saying that we were meant to be obese?
In other words, if your body slows your metabolism when you eat less calories, why doesn't it speed up your metabolism when you eat more? Boom! FLAW!
The answer is in something called Homeostasis.
Homeostasis is defined as the tendency toward a relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes.
What that means in more friendly terms is that your body wants to keep certain things constant - like your temperature.
If you're cold, you shiver to make heat so you get warm. If you're too hot, you sweat to cool down.
Your body has a constant temperature - 98.6 - that it tries hard to keep.
And your body does have a set point that is related to weight, but it is not a number on a scale.
It's your Base Metabolic Rate aka BMR. Mine is about 2600 calories per day and you can find your BMR with our Nutrition Calculator.
What your body is trying to maintain is a balance between available energy and your energy needs /BMR.
But this is where so many people get confused.
Just because you eat calories doesn't mean that those calories are available energy.
This is also why Keto and Intermittent Fasting are so effective for shedding pounds and keeping them off. And why low calorie, low fat diets are painfully unsuccessful and unsustainable.
It's All About The Hormones
I'll use me for an example - remember, my body needs 2600 calories available to my cells everyday.
I also have about 18% body fat. Which - at my weight - means that I have 132,000 calories worth of energy stored as fat.
The disconnect is that even though all those calories are hanging around they're not necessarily available energy.
If body fat is stored energy, and I need the fat energy to meet my BMR, why is fat energy not available?
Insulin resistance is a vicious cycle.
Mostly the answer is the extremely powerful hormone insulin which stops any access to fat as an energy source.
The reason the Keto Diet is so low in carbs and big on fat is that eating carbs stimulates insulin. Fat doesn't.
And there are lots of other things that stimulate insulin and turn off the fat burning.
Inflammation, stress, tasting something sweet or even thinking about sweets can stimulate insulin.
And the insulin stimulation that seems crazy to me: Insulin resistance that is caused by too much insulin actually stimulates the release of more insulin.
When your body is trying to balance available energy with energy needs, there are more variables than the number of calories you eat.
What you eat and how often you eat factor into insulin production.
Even when you don't eat at all, you have some insulin in your system. This is called "fasting insulin" levels.
For some people, like insulin resistant people and diabetics, fasting insulin levels are too high to burn fat.
You Can Re-Balance
You know the whole idea of Keto is that you become a fat burner by getting into ketosis.
Most people can get into ketosis by just getting the carbs out and getting your protein on track and eating mostly fat.
But what about the people whose fasting insulin level is still too high to access fat for energy?
The trick is to control what you can control and start with the easy stuff first.
If you get the carbs out, get protein intake where it should be, and still aren't getting results, then you can eat less often.
Try eating once a day and if it still isn't working, then add some exercise.
You can add some exercise and figure out how to lower your stress, and if that still doesn't work, address inflammation.
If you are still not getting results then try a longer fast like two or three days.
Can You Really Reset Your "Set Weight"?
Ideal body fat percentage for a fit woman is 21-30% for a fit man it is 11-21%.
If you can get your fasting insulin levels low enough and spend most of the day (16-20 hours) at fasting levels, your body will gravitate towards a healthy weight.
The kicker/extra bonus: if you achieve your ideal set weight by controlling insulin, your body will increase your energy consumption get rid of excess calories by burning them instead of storing them.
The Genetic Caveat to Body Composition & Set Weight
Recent studies suggest that genetics play a role in your body’s homeostatic weight set point, but it is only one factor.
The other influences on set weight include hormonal, psychological and environmental factors.
The point here is that you can control many of the factors that determine your set weight.
Of course you can’t change your parents genetics.
But There are lots of factors that you have at least some control over.
You absolutely can change your diet. I recommend healthy Keto and intermittent fasting.
You can prioritize your sleep and exercise
You can address Psychological and emotional issues - some by just getting enough sleep.
And even little changes to your environment can have a big affect on your stress levels.
The Takeaway on Body Composition
You can reset your “set weight.”
If you control the factors that you can, the rest will eventually take care of itself.
That’s all for now - take care of yourself,