Is Starvation Mode Real?

Starvation mode is believed to be a type of metabolic damage that can either stop or even reverse the weight loss process despite a person remaining in a caloric deficit.

So, is starvation mode a real thing?

Research has shown that it’s not, but unfortunately it is not that simple, and there’s a reason that so many people think it exists.

Here’s the problem. Even though starvation mode, as described above, may not be a real thing, we believe it is because we see the effects of our stalled weight loss without actually understanding why it’s happening.

This usually starts when we’re on a diet and gradually losing weight as we would expect when suddenly our progress stops.

We may be (or at least think we are) doing the exact same things that we have been doing previously, but for whatever reason, the numbers on the scale are no longer going down.

It’s at this point that we stumble across some article online that suggests that we have somehow damaged our metabolism. Our panicked body has supposedly entered into “starvation mode” as it tries desperately to hold on to whatever precious resources it has left.

Starvation mode is often described as a condition where our body not only refuses to lose any more weight, but it will hoard any additional fat that it can gather until your diet (aka starvation) is over.

This is also where we get all of these anecdotal reports of people being unable to lose any additional weight until they actually start eating more calories. This supposedly “tricks” their body into believing they are no longer starving, which allows it to let go of all of that extra weight it was holding on to while in starvation mode. 

Help! I’ve broken my metabolism!

Part of the problem here is that we are confusing something that it real (metabolic slowdown) with something that is not real (starvation mode) 

First of all, your metabolism slowing down in reaction to consuming fewer calories is not an indication of metabolic “damage.”

When we are dieting (i.e. eating less energy than we burn), it is perfectly natural for our body to adjust and attempt to conserve its energy.

You have to remember that your body’s number one goal is to keep you alive. This is the reason that it stores body fat in the first place as an energy reservoir that it can dip into when food becomes scarce.

Your body doesn’t realize (or care) that you are trying to lose 15 pounds for your sister’s wedding or that you want to look good for your upcoming beach vacation, all it cares about is making sure that you don’t die.

So when you are suddenly eating less than you normally would, it is natural for your body to burn fewer calories (energy) than it usually would so that it can keep you alive for as long as possible.

Secondly, this doesn’t mean that your metabolism is broken or that you have entered into starvation mode, making it impossible to lose any more weight. At most, it means that it has become slightly more difficult.

This type of metabolic slowdown is natural, but before we can explain the reason why we have to understand how our body burns the energy that we consume in the first place.

Metabolism 101

BMR

Our first stop on our metabolic journey is our basal metabolic rate (BMR), which is essentially the number of calories your body burns just by being alive. 

In other words, your BMR is the number of calories you would burn if you simply laid in bed all day and binge-watched Netflix. Most people don’t realize that their BMR is responsible for the majority (around 65%-75%) of the total calories burned throughout the day.

Another thing that many people don’t understand is the larger you are, the more calories it takes to keep you alive. This means that as you gradually lose weight, your BMR will naturally decrease simply because a smaller body requires fewer calories (energy) to keep it going.

This gradual change in your BMR is just one factor that plays into your overall metabolism slowing down as you continue to lose weight. Again, this is perfectly natural and not an indication of a broken metabolism.

NEAT

Because most of us manage to get out of bed at some point during the day, our BMR is only one part of our metabolism. We also burn additional calories when we walk to the refrigerator or lift our arm to change the channel on the remote. These types of movements are an example of NEAT, which stands for Non-Exercise-Activity-Thermogenesis. NEAT includes all of our actions throughout the day that are not exercise-related.

NEAT can also be a significant factor in the amount of energy we burn daily and is the one that can vary the most from individual to individual depending upon our career, lifestyle, and daily routine.

NEAT will also decrease (often unknowingly) when you are in a caloric deficit because you may feel more sluggish and less active than usual as your body attempts to conserve its energy.

TEF

The thermic effect of food (TEF) is the amount of calories your body burns digesting and absorbing the food that you eat each day. Although this usually only accounts for about 10% of the calories burned throughout the day, it too will gradually decrease when you are in a calorie deficit because you are obviously eating (and digesting) less food than you were before.

TEA

The thermic effect of activity (TEA) is usually what people think of when they talk about burning calories. This is the number of calories that you burn each day from intentional exercise. As you may have guessed, this amount can vary widely depending on your exercise habits (or lack thereof). Depending on how active you are, this can represent anywhere from 0%-20% of your total daily energy expenditure.

Although your TEA is specifically dependent on the amount of exercise you get each day, this too can slow down when you are in a caloric deficit because you may have less energy and motivation to exercise. 

Also, as you continue to lose weight, you will be burning fewer calories from your exercise routine. This is because a smaller body will burn less energy than a larger body doing the same exact exercise, which again is a natural part of the process and not an indication of a broken metabolism.

Metabolism = BMR + NEAT + TEF + TEA

Despite that nice equation above, you have to realize that although these are the big players, there are some additional factors involved that can also affect your overall metabolism. We can group the rest of these under the term “Adaptive Thermogenesis,” which covers everything else that can decrease (or increase) our metabolism not mentioned in our equation above—things such as our body’s hormone changes.

For example, when you are in a caloric deficit, it is fairly common to see your body’s thyroid and testosterone levels drop to some degree. At the same time, your cortisol levels (stress hormone) may rise, which can all contribute to your metabolism slowing down more or less than our equation above might suggest.

A slower metabolism is not a “broken” metabolism

Even though your metabolism will naturally adjust to your decreased energy intake, it will never slow down to the point where further caloric decreases will prevent additional weight loss (aka starvation mode).

Let’s say, for example. You have been losing weight gradually on a 1,800 calories a day diet over the last three months. So far, you have lost 15 pounds, but suddenly you notice that you have not lost any additional weight over the last few weeks. Assuming that you have been accurately tracking your food intake and your exercise habits have not changed, what has probably happened is that 1,800 calories is no longer a caloric deficit due to the effects of your previous weight loss. 

In other words, the number of calories that may have created a deficit for you last month may no longer be a deficit for you now due to the amount of weight you have already lost along with the changes in your metabolism. 

Remember that a smaller body will naturally burn fewer calories than a larger body. So as you continue to lose weight, you will have to adjust your daily calorie goal downward in order to maintain a deficit and continue to lose weight.

But, I’ve heard that if I’m in too large of a caloric deficit or I stay on a diet for too long, my body will enter starvation mode, and I’ll stop losing weight or gain even more as my body turns everything I eat into fat.

We know by now that starvation mode doesn’t actually exist, but also this idea that your metabolism will continue to slow all the way down to zero doesn’t make any sense when you think about it logically. 

Again, there is a limit to how much your body can reduce your metabolism because it requires a certain amount of energy (BMR) just to stay alive. 

Let’s say, for example, your body needs 1,200 daily calories (just a random number) to survive, and you are currently eating 1,000 calories a day (again, just a made-up number and not a recommendation). If this is the case, it would be impossible not to lose weight because your body is burning more energy than it is taking in. Your metabolism cannot slow down any further because it requires 1,200 calories (which would be your BMR in our example) just to stay alive.

So if it’s not starvation mode, what’s the cause of this mysterious stalled weight loss?

In my experience, it’s usually the result of inaccurate food and/or exercise tracking.

Studies have shown that most of us consistently underreport the number of calories we eat. At the same time, we overestimate the number of calories we burn during exercise.

This can be a combination of inaccurate measurement of our food, not measuring (or recording) all of our food, or simply making things up out of shame and embarrassment.

Tracking your daily food intake in an app 

If you don’t keep track of your daily calories, it becomes almost impossible to control them. Luckily our smartphones have made it very easy to do, and there are a lot of free calorie-tracking apps out there, including MyFitnessPal, CalorieKing, Lose it, MyPlate, among others.

Not only are these apps free and relatively easy to use, once you get into the habit of using them, it shouldn’t take more than a few minutes to do each day.

How long do I need to track my food/calories?

This is one of the questions that I get asked the most. The answer really depends on your daily eating habits, the variety of meals you eat, how disciplined you are, and how often you eat out. Generally speaking, I tell people that it’s usually a good idea to continue tracking their calories as long as they are trying to stay in a calorie deficit (i.e. lose weight).

Once you’ve achieved your weight loss goal, then you can experiment with not tracking to maintain it, but until you reach that point, I would recommend that you continue to monitor your food intake closely.

More than exercise, more than healthy eating, more than anything else you can do—tracking your calories is going to make the most significant difference to you when it comes to achieving your body composition goals.

Accurately tracking food calories

Keep in mind that even people who may think they are doing everything right when tracking their calorie intake may be inaccurately measuring their food, which as it turns out, is ridiculously easy to do.

When it comes to health and fitness, we often talk about conscious and unconscious non-compliance. Conscious non-compliance means that we know that we should be doing X, but we choose to do Y instead. While unconscious non-compliance is when we think we are doing X but we are actually doing Y unknowingly.

While conscious non-compliance is very common when it comes to nutrition, a lot of people are surprised to learn that unconscious non-compliance is probably just as common. This also helps to explain why we believe in things like “starvation mode” to begin with. We think we are doing all the right things, but we aren’t getting the results we expect, so we start looking for other explanations that are beyond our control.

Also, keep in mind that when you are tracking your calories, you not only have to record everything that you eat, but you also have to measure your food servings accurately. For example, when you are recording your food servings, you should always measure your food by weight rather than volume (cups, tablespoons, etc..)

I tell people all the time that the best weight loss tool you can buy is not a treadmill or any other exercise equipment–it’s a digital food scale. Eyeballing and estimating your food servings will almost guarantee that you are underreporting your calorie intake.

Finally, research has shown that a smaller calorie deficit is usually a better idea than a large calorie deficit when trying to lose weight simply because it is easier to stick to in the real world. 

When it comes to losing weight, being able to stick to your calorie goal day after day is probably the biggest predictor of success. 

Of course, if you’re in a controlled lab setting or a contestant on a reality show like the Biggest Loser, you might be able to stick to an 800-1,000 calorie a day diet, at least in the short term. Out in the real world, however, sticking to an extremely low-calorie diet like this is far easier said than done.

Although eating a very low-calorie diet will never prevent weight loss due to “starvation mode,” it can potentially create nutritional deficiencies and other health-related issues.

Tracking your exercise calories burned

Even though tracking the calories you eat may be essential, I wouldn’t worry too much about tracking the calories that you may (or may not) have burned while exercising. 

Just as we tend to underreport the number of calories that we eat, most of us tend to overestimate the amount of calories that we burn during exercise. 

There’s also a bit of a reward mentality that often goes into tracking your workouts. For example, how many times have you rewarded yourself with a smoothie or a Chipotle burrito on your way home from the gym because you “earned” it?

I’ve talked a little bit about this topic of whether or not it is worth tracking your calorie burn during your workouts, but overall I’m not sure the benefits of tracking outweigh some of the potential risks.

Keep in mind that when I’m talking about tracking your workouts, I’m specifically talking about tracking the number of calories you are supposedly burning during your workouts. This is not the same thing as recording what exercises you are doing, how much weight you are lifting, and how many times you lifted it during your workout.

The bottom line:

Starvation mode is not real.

What is real is that many of us will occasionally experience weight loss plateaus where we are (or at least we think we are) still doing the right things, but our weight loss progress has stopped.

This is most often a result of underreporting our actual food intake and overestimating the number of calories we have burned during exercise.

While it’s true that our metabolism will slow down as we continue to lose weight due to lower daily activity and the fact that a smaller body requires fewer calories to operate than a larger body, this is not a sign of metabolic “damage.”  

Because our body requires a certain amount of calories just to survive (BMR), our metabolism will never slow down to the point where weight loss will completely stop or cause us to gain weight.

In other words, if we consume less energy (i.e. calories) than we burn, we will always lose weight, but only if we track our food intake accurately and consistently. 

What do you think?

Have you ever hit a weight loss plateau and wondered if you had entered into starvation mode? How did you get that point and what type of information had you heard about it? Were you able to break through this weight loss plateau? If so, what did you do differently and what would you recommend to someone who may be going through the same experience? Please take a moment to share your story with us in the comment section below.

References: 

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Camps SG, et al. Weight loss, weight maintenance, and adaptive thermogenesis. Am J Clin Nutr. 2013 May;97(5):990-4.

Dulloo AG, et al. Adaptive thermogenesis in human body weight regulation: more of a concept than a measurable entity? Obes Rev. 2012 Dec;13 Suppl 2:105-21.

Lichtman SW, et al. Discrepancy between self-reported and actual caloric intake and exercise in obese subjects. N Engl J Med. 1992 Dec 31;327(27):1893-8.

Maurer J, et al. The psychosocial and behavioral characteristics related to energy misreporting. Nutr Rev. 2006 Feb;64:53-66

Muhlheim LS, et al. Do unsuccessful dieters intentionally underreport food intake? Int J Eat Disord. 1998 Nov;24(3):259-66.

Novotny JA, et al. Personality characteristics as predictors of underreporting of energy intake on 24-hour dietary recall interviews. J Am Diet Assoc. 2003 Sep;103(9):1146-51.

Pietiläinen KH, et al. Inaccuracies in food and physical activity diaries of obese subjects: complementary evidence from doubly labeled water and co-twin assessments. Int J Obes (Lond). 2010 Mar;34(3):437-45.

Tremblay A, et al. Adaptive thermogenesis can make a difference in the ability of obese individuals to lose body weight. Int J Obes (Lond). 2013 Jun;37(6):759-64.