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Can you gain weight from not eating enough?

Updated: Jan 21, 2021

You're here because you want to lose weight.

But let me guess, if you're reading this, you're not actually losing weight.

You've tried everything and you've come to the conclusion that,

"I'm not losing weight because I'm not eating enough, shall I increase my calories?"

And you want to know if this is true and if so, what can you do about it?

What you are referring to is starvation mode.

What is starvation mode?

Starvation mode is the supposed state a person is in when their excessive approach to losing weight has slowed their metabolic rate so much that it completely stops any further weight loss from occurring or even more amazingly, cause weight gain ... even though the said person is still in a calorie deficit.

A quick recap: Calories

Calories are energy.

Your body uses calories for everything it has to do.

From intense exercise like running and weight training to everyday tasks like standing and tying your shoes and activities like gardening and walking... they all burn calories.

Did you know that your body actually uses a ton of calories every single day even when you aren't doing anything?

Keeping your body alive and functioning burns lots of calories.

Include things like walking, housework and gardening.

If your goal is to lose weight, you can either increase the number of calories you burn through exercise, reduce the number of calories you consume, or do both.

But, to lose weight, you must be in a consistent calorie deficit.

What are the supposed causes of starvation mode?

I've heard people claim that starvation mode is caused by:

  • Crash dieting

  • Yo-yo dieting

  • Not eating enough calories

  • Dieting for too long

  • Working out too much

  • Skipping meals

Above all else, the fundamental idea for starvation mode is that if you don't eat enough for a prolonged period, your body will shut down various processes to preserve the energy it has, including holding onto any weight you're trying to lose.

And, to then supposedly reverse this starvation mode process, the person needs to eat more calories to theoretically speed up their metabolism, burn more calories and then lose weight.....!?

Whew ... are you still me with?

Nope ... me neither.

So, once and for all...

Bottom line: Is starvation mode real?

No, it's not.

In fact, I'll go as far as to say that the concept of starvation mode is completely ridiculous when it comes to most peoples weight loss.

It's not how the body works.

Clearly, eating too little is not something that anyone should advise but you only need to look at people who have suffered in awful environments throughout history to see that being underfed does not lead to weight loss stalling.

Show me a prisoner of war that was released overweight.

If starvation mode existed, simply no-one would starve, including those in countries hit by terrible famines.

But wait, I'm definitely not eating enough, I'm 100% in a calorie deficit and I'm not losing weight?

Why am I not losing weight in a calorie deficit?

Simply put and in the nicest possible way ...

I promise you that you're NOT in a calorie deficit.

To lose weight, you must be in an energy deficit (calorie deficit - consume fewer calories than you burn over a period of time).

What happens is that you're either under-reporting the number of calories you are eating or you are restricting too much and then over-indulge every few days.

Which means that over time, your calories consumed average out and cancel any deficit.

A bit like your bank balance.

You save £50 every day of the week and by Friday you have £250 sat there.

However, Saturday comes and by the time you've withdrawn enough to cover some new clothes, a nice meal, a few drinks and a taxi home ... you're back at £0.

Same with calories.

You save 500 calories a day Monday to Thursday, Friday is cake day in the office and then Saturday's a few drinks and a big takeaway, and guess what you're back to square one, deficit gone.

Studies have shown that people eat up to 1,000 more calories per day than they report.

So that's 3,000 daily calories instead of the 2,000 recommended for women.

And, 3,500 daily calories instead of 2,500 recommended for men.

A calorie surplus of 1,000 calories a day could lead to you gaining around 2lbs a week, that's 8lbs a month.

I don't even want to calculate what that adds up to over a year.

Is there any truth to it?

Hopefully, I've been clear enough and you understand that to lose weight you must be in an energy deficit.

And, as you lose weight, there's going to be less of you, so as your body mass decreases, so does the amount of calories you need to eat.

A concept called metabolic adaptation.

This is normal.

The natural response by the human body to a calorie deficit and weight loss is for your metabolism to drop.

That initial drop you see on the scales at the start will eventually slow down and even out as your body settles into a routine.

This is why the further you get into your weight loss journey, the more likely it is that your progress slows down.

Don't rely on your scales

The reality is, your weight will fluctuate hourly depending on when you last ate, what you ate, and other factors, such as a women's menstrual cycle.

Which means that if you equate your weight with your body fat, every time the number on the scales goes up, you assume that you are gaining weight.

And, if it that number doesn't change, you think that your calorie deficit isn't working.

This then leads to you feeling unmotivated and giving up, whereas in actual fact, if you just stayed consistent in your deficit, the scale would drop back down again.

It's important to remember that weighing yourself isn't unhealthy.

What is unhealthy is associating your worth as an individual to what the scale says.

Use the scales to collect data so you can make adjustments and NOT

to judge yourself.

One last thing

Adaptive thermogenesis.

Often, people don't realise that when they are in a calorie deficit, they gradually start to move less and less throughout the day.

When actually they should be increasing their NEAT (non-exercise activity thermogenesis),

* a very fancy way of saying how much you are moving, like walking, gardening, shopping or cleaning.

Reducing your activity levels can lead to the individual burning fewer calories throughout the day, further slowing down weight loss.

Get your NEAT up to burn more calories throughout the day.

To sum up

No, starvation mode doesn't exist.

Yes, extreme, prolonged calorie restriction will have negative consequences for the individual.

Yes, your weight loss will slow down over time.

Yes, if you're not losing weight, chances are you're under-reporting your calorie intake.

Yes, you should move more.

Yes, you should see a doctor to rule out any medical issues as to why you're not losing weight.

Ben Yates is a personal trainer based at Places Gym Hinckley and Hinckley Leisure Centre in Leicestershire.

To book your free personal training consultation click here


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