Starvation Mode; Myth or Reality?


The majority of people I come across in my line of work want to lose weight. Sure some want to gain some muscle mass, and some want to improve sport or athletic performance, but by and large, weight loss is my bread and butter (ironically).

Losing weight can be great, it has vast numbers of health benefits, improves mood, mental focus and also can make you look great too.

If you have ever tried to lose weight, you may have found that after an initial great few days/weeks, the progress seemed to tail off, or even stop completely. Or maybe you started a diet, and although you were trying really hard, the weight just didn’t seem to be shifting. If this is the case, you may have been told one or more of a dozen different reasons as to why you have plateaued from water retention to gypsy curses.

The two most common reasons given for weight loss plateaus tend to be 1- Muscle outweighs fat & 2- Your body has gone into starvation mode.

Now number 1 as a statement is true, muscle does in fact weigh a lot more than fat however, muscle takes time to build, to build lean muscle at the same rate or greater than you are losing fat is unlikely.

Today however we’re going to look into the other reason, “Starvation Mode” which is where weight loss or energy deficit has caused your body to enter a weight loss preventing state.

Now there are two very different ways of looking at starvation mode, one of which is unfortunately very wrong and often gets pedalled about. The other does indeed have scientific backing but is not so popular and you’ll see why as we go through.

The common way of explaining starvation mode is to say;

“When losing weight you need a calorie deficit. BUT if you eat too few calories your body will slow your metabolism down to conserve energy to the point where weight loss will completely stop or even reverse.”

So basically eating too little causes your body to stop losing weight and in some cases you can even gain weight through eating too little. To get out of this state you must increase your calories, not reduce further.

So let’s take an example of a person that exercises, eats healthy and generally “eats right” however they aren’t losing any weight. This theory would seem to make perfect sense right? And it would, except for one teeny tiny thing….it’s wrong, like, really wrong.

A calorific deficit (taking in less than you’re burning off) will result in a decrease in mass in 100% of subjects and tests. Even in some of the most extreme experiments with ultra low calorie intakes (really, really not recommended) weight loss still occurred. Weight plateaus at a calorie deficit are a myth, weight being gained at a calorie deficit is an even bigger myth up there somewhere between unicorns and dragons.

“Weight plateaus at a calorie deficit are a myth, weight being gained at a calorie deficit is an even bigger myth…”

Now, what is real is that your body changes when you drop your calories below your expenditure rate. This is better described as the starvation response, or to give it it’s fancy title adaptive thermogenesis (pretty cool huh)

Basically, as we said earlier, weight loss is generally a good thing in this day and age of obesity. However your body doesn’t see it that way. Your body can’t tell the difference between you dropping your calories because its coming up to swimsuit season and you dropping calories because you’re stuck in a desert and there’s no Asda within 1000 miles of you and so it adapts.

This response was useful way, way back when our ancestors were foraging around and didn’t know when they were next going to eat. It stopped them from dying. Our bodies don’t like extreme and prolonged calorie deficits caused by not eating enough, being too active or a combination of the two. As such, it acts to make it harder for us to continue doing this. Normally, your body will burn calories in 4 different ways.

  • Calories burned through maintaining vital functions aka Basel metabolic rate (BMR) e.g. breathing, heart rate, brain function.
  • Calories burned while digesting aka Thermic Effect of Food (TEF) which can be as much as 10% of calorie intake.
  • Calories burned through activity aka Thermic effect of exercise (TEE) e.g. you know….being active…duh
  • Calories burned through movement aka Non-Exercise Activity Thermogenesis (NEAT) e.g. fidgeting, changing posture, tapping your foot etc

When calories are dropped too low or energy expenditure is too high your body accts accordingly by

1- Slowing down your metabolism aka that adaptive thermogenesis thing I talked about earlier and which I suggest you learn to say in order to sound brainy at your next dinner party. As mentioned above, your body can’t tell the difference between you wanting to look like a sexy beast and you being trapped somewhere with limited food, it reacts to both situations in the same way, by slowing down your internal processes in an attempt to conserve energy. This process is REAL and documented through many studies, but, as stated previously, it’s much less than people think, enough to slow weight loss a little but nowhere near enough to make it stop completely

2- It reduces both your conscious and unconscious activity levels.

3- It causes increases in hunger and food cravings, causing you to eat more than you’re attempting to.

4- It makes you feel pretty awful physically and mentally. This is pretty self explanatory.

These reasons, plus a whole host of other health reasons are why you should NOT severely restrict your calorie intake and/or do extreme amounts of exercise.

However, even if you did do this, you’d still lose weight.

(This is just an example to prove a point please, please, PLEASE don’t starve yourself, I don’t recommend this, don’t do it, really, don’t, okay, deal? Deal.)

So if it isn’t starvation mode, what is causing the weight loss to plateau?

Well generally it can boil down to simple math.

If I have people come in to see me and they say “I want to lose weight, I’ve been trying X,Y,Z diet and the weight isn’t shifting” the first thing I’ll ask is, “How many calories roughly are you eating per day?” Most won’t have a clue. Sometimes they do but other things can go wrong. One guy I had detailed out all his food calories for me however when I asked about drinks he said “oh, id forgot about those” he was consuming nearly an extra 500 calories through drinks (which is very easy to do if you drink lots of tea or coffee with milk and/or sugar or squash or juice) and so was actually losing his deficit completely due to that. Also be careful about food labels as many will simply state the calories per portion of something (e.g. half the bag of crisps not the whole bag).


If you’re concerned with losing weight, stop spending hours reading up about some new fad diet, take some time to work out your intake being as accurate as possible, it will be a much more useful use of your time. There’s always going to be a small amount of guesswork but as long as you keep track of everything going in, results will happen!

“If you’re concerned with losing weight, stop spending hours reading up about some new fad diet, take some time to work out your intake…”

There are some really useful free tools available online to help you work out roughly what your energy expenditure is per day. Try out some of the following links;




Now you know what you’re using per day, create a manageable deficit and the weight will drop. If the weight loss starts to slow, redo the calculator as your expenditure will drop with your weight loss as you now weigh less.

Another brill way to keep your adaptive thermogenesis (I just like saying it) in check is to do resistance training (training against a load).

This can be through lifting weights or with bodyweight exercises. Studies have shown that by adding in resistance training to your week, muscle mass will be maintained and the slowing down process can be mitigated.

Having a high protein diet can also be beneficial; it prevents the breakdown of muscle tissue for use as energy and more muscle mass equals less slowdown.

Protein is also great for reducing appetite and is actually a metabolism booster as it required more energy to break down.

So, all in all, starvation mode is a bit of a myth however there is such a thing as a starvation response. Starvation response however is not a simple on/off state; it is an entire spectrum of adaptations made by the body. Without it, humans probably wouldn’t exist today. Unfortunately in this day and age, particularly in the Western world, overfeeding is a much more common problem in than starvation.

Check your calories, do your exercises, measure, rinse, repeat. Simple

Image Credits

“Vader’s got me on this Corellian diet fad..!” | Flickr – Photo Sharing! : taken from –
Author: Tim Norris

022.365: Nutrition | Flickr – Photo Sharing! : taken from –
Author: Dan Domme