Does your body go into 'starvation mode' if you diet for too long?

To lose weight, you need to consume fewer calories than your body needs throughout the day. You can do this by increasing your physical activity and paying attention to your diet.

However, there are stories that your body goes into 'starvation mode' or 'survival mode' when you diet for too long. But is that true?

What we mean by 'starvation mode'

You may have heard of 'starvation mode' before. Here's the story: when you've been dieting for a while, your body gets 'shocked' because it's receiving far fewer calories than it's used to. Since it doesn't know when you'll return to your old eating patterns, it starts conserving energy as a precautionary measure: instead of burning calories, it holds onto them.

The result? You stop losing weight no matter how hard you try! On paper, it all sounds very logical.

But does this claim actually hold true?

Fact or fiction?

The truth lies somewhere in the middle. The so-called 'starvation mode' is a natural response of the body to long-term calorie restriction. This is also known as 'adaptive thermogenesis' (1).

Research shows that during drastic weight loss, the body does indeed burn significantly fewer calories (2). The body does this to prevent starvation and to continue distributing the energy needed by organs.

However, the idea of a complete standstill where you stop losing weight is nonsense. As long as you burn more calories than you consume, you will continue to lose weight.

On the flip side, if your body receives absolutely no calories, you will genuinely starve over time. To keep your body functioning, it constantly needs energy. This mythical 'starvation mode' will not allow you to keep going despite having no calories left.

Why am I not losing weight (as quickly)?

Nevertheless, many people are convinced that their body has entered 'starvation mode' after prolonged dieting. At the beginning, the pounds fly off, but over time, you practically stay at the same weight. How can this be explained?

It's actually quite simple: when you weighed 120 kilograms, your body needed more energy to function. Now that you weigh 90 kilograms, you burn significantly less energy. However, you still consume the same number of calories as when you started dieting (3). Eventually, your calorie intake equals the amount you burn. The result: you stop losing weight (or lose weight less rapidly).

When you reach this plateau, your body is not in 'starvation mode,' but you simply need to burn more calories and/or consume fewer calories. You'll have to exercise more or adjust your diet again. Easy peasy!

Losing weight responsibly

Actually, it's quite healthy to occasionally reach such a plateau. Losing weight too quickly has the opposite effect. Research shows that rapid weight loss leads to a lower calorie burn (4) and primarily burns muscles and water (5). Moreover, rapid weight loss can result in a weakened immune system (6).

Conclusion

While it's true that the body will burn fewer calories after a prolonged calorie deficit, it won't go into starvation mode due to long-term dieting. By losing weight responsibly and regularly reviewing your diet and exercise routine, you can continue to lose weight in a healthy manner.