Is Starvation Mode Real?

Starvation mode is a common fear among many dieters - mainly because some experts proclaim that if you are restricting your calories too low, especially over an extended period of time, you may be hindering your rate of fat loss and damaging your metabolism. But is this really the case? And at what calorie deficit do you enter starvation mode?

Here’s where this popular claim comes from and what the science says about it.

What is Starvation Mode?

Starvation mode is not a scientific term. It is a popular phrase used to imply that when you cut calories too low, your body goes into a protection mode, slowing your metabolism and calorie output so that you stop losing weight.

This concept is rooted in your body's survival mechanisms. If you ever found yourself without food for long periods of time, it would not be beneficial for your body to continue to burn calories at a normal rate; instead, your metabolism would shift to preserve as much energy as possible to prolong your life. But starving to death is not quite the same thing as dieting and you will still lose weight in the process of wasting away without food.

How Long Can You Survive Without Food?

With access to water and electrolytes, your body can survive for quite some time without food, depending on the person and how much body fat you have. Some research suggests that you can go more than a month without food (1,2,3). And in some religions, long fasts are commonly practiced with potential health benefits (4).

So, is Starvation Mode a Myth?

Starvation mode is not a real term, but metabolic adaption is, and it’s a known phenomenon. How drastically it affects your weight loss progress is another story.

Your body can compensate for decreased calories by slowing your metabolism down as much as 30% through adaptive thermogenesis (4,5,6,7). But the effects of adaptive thermogenesis are typically short-lived, and for most the difference could be as little as a 5% decrease in basal metabolic rate (BMR), and it does not indicate a damaged metabolism (8). 

In addition, more recent research suggests that it is not the actual act of fasting or calorie restriction that causes changes in metabolism (9). And increasing evidence implies that fasting may be beneficial for weight loss and health in some people (10,11,12,13).

So what is the verdict?

In all of the studies referenced to support starvation mode, weight loss was a factor. And it is crucial to note that any weight loss can cause you to have a lower BMR - since it just takes less energy to move around a smaller object.

Cutting calories does not cause your metabolism to slow, weight loss does.

Some people will see no significant difference in their resting metabolism while dieting, as this is highly individualized and dependent on a number of other factors like body fat percentage, overall diet, dieting history, fitness level, gender, etc. And others may gain muscle mass, even though their overall weight decreases, causing them to see an increase in their metabolic rate. 

Your body doesn’t typically want to lose a bunch of weight. It wants to hold on to that stored energy in case starvation actually does become a threat. So with any decrease in calories, you will often see a shift in appetite-regulating hormones and fuel utilization.

These factors combined are some of the reasons why losing body fat can feel impossible (14). But this adaption is only temporary and it doesn’t mean that your body is in starvation mode, or that you won’t lose weight if you keep at it. As long as you remain in a calorie deficit, you will continue to lose weight.

Of course, this also doesn't mean starving yourself is the best approach either. 

Why You're Not Losing Weight and How to Fix it

If you find that you’ve hit a weight loss plateau, it does not mean you are in starvation mode. Some more common factors are likely at play, including the following:

You're Not Tracking Your Food Intake

It's pretty impossible to know if you are in a calorie deficit if you aren't tracking your food intake. Before assuming something else is at play, keeping an accurate food diary is the best place to start.

Even if you've been tracking, take a look at how diligent you are being with this habit.

  • Are you accurately portioning and weighing out the food you eat?
  • Are you including all foods and drinks, and tracking every day, even cheat days and weekends?
  • Are you including added toppings and ingredients like cooking oil, butter, salad dressings, etc.?

You can also use your tracking app to get weekly calorie and macro averages - this is the best way to see how well you’ve stuck to your diet consistently, as well as where you could use some work. To see your weekly calorie average in the Trifecta app, use the following steps: 

  • Step 1 - In the app, open your nutrition tracking and go to the daily summary
  • Step 2 - Select “calories” from the top and change the summary to “weekly”
  • Step 3 - Locate your weekly calorie average


You're Not Eating the Right Amount of Calories 

Typically, if you aren't losing weight, you are eating more calories than you think. Or if you've recently lost weight, you likely have a new maintenance calorie amount and may need to eat fewer calories to continue losing. This is why many popular weight loss plans will use a phased approach to cutting, helping you to stay in a calorie deficit and continue losing weight with incremental calorie cuts.

Start by figuring out how many calories you need to eat a day to maintain your current weight and then calculate your new weight loss calorie needs from that starting point. 

You're Always on a Diet

It might also just be that your body needs a break. If you've been dieting for more than a few months, it might be time to give your body time to adjust to your maintenance calorie level. Jumping from one diet to the next and constantly trying to cut calories can do more harm than good. It is much easier to stick to a diet and continue to get results if you understand how to maintain results in the first place. 

Been on a really low-calorie diet for a while and scared to add calories back in? Try upping your intake a few hundred calories a week to start, until you reach your maintenance level. And then stick to your maintenance for at least a month to give your time to adjust and reset your metabolism. 

You're Too Focused on the Scale

Often times dieters are focused solely on fat loss, but their total body composition is crucial to getting better results and making them stick. Not to mention, if you are cutting calories too low for too long, you’re at risk of losing precious metabolic tissue - your muscle (15).

Gaining muscle is essentially the opposite of “starvation mode”. Your muscle mass is the biggest determinant of your metabolic rate, and the more you have, the more you can eat and maintain your weight. Plus, muscle is the tissue behind that lean, toned look most of us are striving to achieve in the first place.   

While muscle growth is typically achieved through weight gain, which would ultimately increase your metabolism even further, it is possible for some people to build muscle in a calorie deficit. But at the very least, you should be focused on protecting your muscle while dieting.

To keep your lean mass intact while dieting, be sure to incorporate the following:

  • Lift weights: Research suggests that one of the best ways to maintain muscle is to keep it active and through regular strength training (16).
  • Eat more protein: Eating a high protein diet has a number of benefits for fat loss and has also been thought to help support your lean mass when cutting calories (17,18).

What are the Minimum Calories for Weight Loss? 

While starvation mode may not technically exist, starving yourself to lose weight is still not recommended. A very low-calorie diet may work at first, but it’s likely not going to do you favors in the long run. It can be dangerous for some people, lead to disordered eating habits, and does not typically lead to sustainable results, since most people do not change bad habits once they resume eating again. In addition, extreme dieting is impossible to maintain, causing painful hunger cues, irritability, mood swings, decreased energy, poor concentration, and sucks your willpower dry, all of which makes sticking to a diet that much harder. 

Instead, stick to a more attainable approach to dieting with no more than a 15-20% decrease from your estimated daily energy needs. Slow and steady weight loss of 0.5 to 1% body weight per week is much easier to keep off and you will be much happier and more successful with a more measured and sustainable diet plan approach.

Need help figuring out how many calories you need each day? Get your personalized nutrition goals and establish healthy habits with the Trifecta app.
Get the App