Have you seen on the news recently how yet another third world country is having an obesity crisis due to ‘starvation mode’?


Me neither!

That’s strange, as my mate Dave said he’s not losing weight as he in starvation mode.

Let’s take a look at the details to see if Dave is full of shit.

What is Starvation Mode?

Lack of weight loss or stalled progress is often blamed on the concept that your body is eating too little calories to burn fat.

If we look at the law of thermodynamics (sounds fancy hey?), which is calories in vs. calories out. In order to lose body fat, we need to ensure the amount of calories consumed is lower than the calories we burn or vice versa. All diets and programs must adhere to this law to be successful no matter what method is used.

With this law in mind, I find it hard to understand how too little calories results in no fat loss. Unless you are defying to laws of physics, the only obvious answer is that you are not in a calorie deficit.

Metabolic Adaption

If I drop the sarcasm and piss taking just for a minute, there may a small amount of logic in what is defined as ‘starvation mode’.

As evolutionary creatures, our bodies do not like to lose weight. From a caveman perspective, losing weight meant that food was scarce and you were likely in a spot of bother/going to die. During this time, our bodies are clever little buggers and decides to do something about it.

There are a few things that change:

BMR – or basal metabolic rate reduces as our bodyweight lowers. Our bodies require less energy (food) as we have less tissue (fat/muscle) to maintain.

NEAT – or non-exercise activity thermogenesis. This is the amount of calories you burn during daily activities that you wouldn’t class as your typical exercise. When you are in a calorie deficit (and some time afterwards) you will sub consciously reduce the amount of activity you carry out. You fidget less, move less and therefore require less calories.

Exercise Efficiency – You are likely to become more efficient at exercise. As you have less weight to carry around, you will burn less if going for a run for example. Our bodies also become more efficient and burning calories and require less calories to carry out the same tasks.

There are many more metabolic adaptions that take place, but this just gives you an insight to a couple of the bodies changes. Read the full details here.

Whilst these metabolic adaptions are taking place, they are probably not as severe as you might think. In one study it is estimated that your calorie expenditure will reduce by 12.8 calories per kg lost. So if you lost 10kg you would have to reduce your overall intake by 120 kcals per day (about as much as a large banana).

The Real Answer

The real reason for your stall is likely to be from lack of patience, inaccuracies in calorie counting or over estimations in your energy expenditure (the amount of calories you burn). In one study they found that the individuals were not losing weight even on less than 1200 kcals per day. They found that they under reported their calorie intake by 47% and over reported their physical activity by 51%.

Whilst I think we can safely say ‘starvation mode’ doesn’t exist. There are some minor metabolic adaptions that take place, but are much lower than first thought. Before blaming your lack of success on a mythical bodily function, take a look at your calorie counting accuracies, your physical activity or just be more patient.  

If you need help estimating your calorie intake, get in touch today and I will be more than happy to help. I offer online and 1 to 1 personal training to help people get fitter, faster and leaner.