Starvation Mode
You may have heard that consuming too few calories could trigger “starvation mode.” People in the diet industry often use this term to explain what happens when your weight loss plateaus as a result of calorie restriction. It’s true that the rate at which you burn calories can slow down when you eat significantly less. It’s the body’s way of ensuring survival. Your body will slow your metabolism down in an effort to preserve muscle mass, and your weight loss efforts stall.
“Starvation mode” is the body’s natural response to long-term calorie restriction. It happens when your body reduces the number of calories it burns at rest to slow weight loss and restore your energy balance.
The term “starvation mode” isn’t really accurate when we’re talking about diets. True starvation isn’t happening given our modern environment where food is readily available and accessible most of the time. But the physiological response to not eating enough calories (caloric deficit) is very real. Whether it can prevent you from losing weight or even cause you to gain weight is not as clear.
When food was scarce back in the day, slowing the rate at which we burn calories was the body’s way of ensuring survival. Because your body and brain prioritize long-term survival over losing body fat, when you reduce calories you may notice your body puts the breaks on weight loss.
You won’t enter starvation mode after intermittent fasting, slightly limiting your calories, or even fasting for 24 hours. It isn’t an ‘on’/’off’ switch. Rather your body adapts over time to increased or decreased calorie intake. In modern times, “Metabolic adaptation” is a better term than starvation mode.
As you lose weight, there’s less of you, so you require fewer calories. As you go deeper into a calorie deficit, your metabolism will slow down. That’s a natural human response to a caloric deficit. But this works in reverse as well: when you start eating more, your metabolism picks up. Even a completely healthy and medically sound eating plan may result in some degree of metabolic adaptation. In fact, a comprehensive review published in the International Journal of Obesity explains that losing just 10 percent of your body weight results in a 20 to 25 percent dip in your daily caloric burn. Initially, that is. It is normal for your metabolic rate to decline slightly while dieting, but it bounces back once you start eating more, and this decrease isn’t enough to significantly impact weight loss or damage your metabolism, regardless what you may have heard about long term metabolic damage. [1] I would advise against a calorie deficit greater than 400-500 calories per day, honouring a small 10-15% reduction or
calorie deficit. I would also ensure you are not just at a ‘ weight loss plateau’ which is commonly mistaken for ‘ starvation mode’ when the scale suddenly stops or slows. There are various ways we can work through a plateau while supporting your metabolism and metabolic process. This includes increasing strength training, increasing protein consumption, and ensuring your calories aren’t dropping below 1200 calories for sustained periods of time.
Metabolic adaptation is a normal process
So, how do you know if you are going to go into ‘ starvation mode’? Unfortunately, there isn’t an exact formula that can tell you this, the key is being in tune to your body talk, and the signs and symptoms of what your body is telling you, that may give you an indication. This can happen if you have been following an extremely restrictive low calorie plan for a prolonged period of time. However, there are ways to lose weight, have more energy, and consume the nutrients you need without starving.
Things to look out for are:
- You’re constantly hungry
- You’re losing muscle mass
- Your hair is falling out
- You’re exhausted
- You’re irritable and grumpy