What Happens to Your Body Composition When You Starve to Lose Weight | RZone Fitness (2023)

You may have a few (or more) extra pounds you want to lose. What do you do? Naturally, like most people, you turn to tried and true methods of weight loss, diet, and exercise. You begin running or hitting the weights a few days a week. You start to tighten up your diet, omitting junk food and cooking at home more often.

For some people, the results from this process are not achieved quickly enough. We live in a world of immediate gratification. If you can’t hit your goals, like yesterday, what do many people do? Some turn to starvation diets, or extreme diets that restrict calories far below their daily energy needs.

(Video) What Does Starvation Do To The Body?

They might drop pounds rather quickly, just look at the Biggest Loser for evidence of that. But what really happens to their bodies? What are the short and long-term health effects of starvation on body composition?

What our body is made of

Body composition is the term used to describe the components that make up your body: fat and fat-free mass. Fat-free mass is made up of everything that isn’t fat, such as protein (lean muscle, organs), water, and minerals (i.e., bones and iron in the blood).

To change your body composition, you can’t simply focus on the larger goal of weight loss. Instead, your goal is twofold: reduce fat mass while maintaining or increasing Lean Body Mass. But why should you focus on changing your body composition instead of weight loss?

Simply put, increasing lean muscle will give you the appearance of being thinner, even if the number on the scale doesn’t move. That is because muscle is more compact than fat. So focusing on body composition, as opposed to fat loss, can help you improve your overall appearance and reduce body fat while increasing strength.

Why we choose starvation

What Happens to Your Body Composition When You Starve to Lose Weight | RZone Fitness (1)

The standard model of weight loss is calories in vs calories out. If you consume more calories per day than what you burn, you will gain weight; by burning more calories per day than you take in, you will lose weight. Having a calorie restriction is important if you are trying to see the number on the scale decrease.

As discussed earlier, many people choose the all-or-nothing, die-hard approach to weight loss and opt for calorie levels far lower than what is recommended, prompting them to lose weight rapidly. Starvation diets may get you to “a goal weight,” but at what cost?

What happens to the body when it starves

What Happens to Your Body Composition When You Starve to Lose Weight | RZone Fitness (2)

Research indicates people who used starvation diets for weight loss, eating 50% of their energy needs for three weeks, did decrease their body weight overall. However, they alsoreduced their lean muscle mass by 5%. If the state of starvation is maintained chronically,lean muscle mass and organ size are decreased by 20%.

(Video) Why Starving yourself isnt the right way to lose weight

Likewise, a study on mice foundlean mass and lean muscle mass were sacrificed during starvation; however, body fat stores were relatively the samein mice on a control diet and obese mice on starvation diets.

Weight loss via starvation causes individuals tolose significant amounts of lean muscle massand Lean Body Mass, which encompasses water, bones, organs, etc. Reducing the mass of your bones is problematic, as thatdecreases bone density and can make you more prone to injury. Conversely, increasing Lean Body Mass increases bone strength and density, a common concern for many Americans as they age.

One study using human participants indicated dropping significant amounts of calories from the diet lead to significant weight loss and decreased lean muscle mass. However, participants alsogained back nearly all of the fat they lost, within 8 years.

This prompts the discussion and understanding of an important topic- metabolism. More so,chronic starvation leads to changes in metabolism. Metabolism and resting metabolic rate are directlylinked to Lean Body Mass. A person with greater body mass will require more energy to function day to day, thus will have a larger basal metabolic rate (BMR). As weight decreases, so does BMR.

This means that there’s a certain number of calories necessary to maintain your lean mass. If you go below this number, your body will be forced to break down these muscle stores in order to create energy.

Starvation diets have far-reaching negative effects on the body. Starving to lose weight changes the metabolism, reduces lean muscle, reduces bone density, and decreases strength.

Returning from a starving state

What Happens to Your Body Composition When You Starve to Lose Weight | RZone Fitness (3)

Perhaps you opted for an ultra-low-calorie diet, placing your body in starvation mode. You’ve lost tons of weight and are ready to return to “normal” eating. So far, your body has also responded by losing muscle and decreasing BMR. But something else interesting happens to the body after a period of starvation.

Thebody’s systems do not “reset” after starvation. What does that mean? The body tunes itself to focus on significant weight loss at the expense of body fat mass, lean muscle, and other lean mass. It reduced its basal metabolic rate. Yet, once a person returns to a normal calorie level, the body cannot adapt.

(Video) How a Starvation Diet Makes You Fatter

The body cannot adapt from dropping to an ultra-low caloric intake to lose weight and return to a higher caloric intake to maintain the weight loss. The body will store the extra calories as fat.

This is because the body is nowprimed to replenish the lost fat stores, not lean muscle, lost during starvation. Starving to lose weight makes your body more likely, in the long run, to replenish fat. It uses the new basal metabolic rate from starvation mode.

Lean individuals were more likely togain more fat after starvation. To that end, the body’s system didn’t “reset” itself until all the body fat lost during the period of starvation was regained. This negates any progress made during this period.

One of the reasons this may be the case is becauseblood leptin levels decrease in individuals who lose a lot of weight via starvation. Leptin is the hormone that signals satiety. It is produced by fat cells and helps to regulate energy balance and inhibit hunger. In short, it signals the brain that you are not hungry.

Yet, those who starved for greater weight loss lowered their leptin levels, putting them at risk of regaining the weight because the body wasn’t signaling the brain correctly. Low blood leptin signaled to the brain the body was not full or satisfied after eating, causing them to eat more.

Research indicatesextreme weight loss by starving yourself is often not sustainable. Take that example of the Biggest Loser into consideration again. What happens once the show ends? Most of the contests gain a significant amount of the weight back.

Among a study of 14 Biggest Loser contestants, 13 of the 14regained a significant amount of the weight lost within 6 years after competing. Furthermore, their basal metabolic rate decreased with the weight loss, as expected. Yet, once contestants put the weight back on, their BMR did not increase with the weight.

Recall the correlation between mass and BMR. Someone at a higher weight has a greater BMR. Yet, Biggest Loser contestants who lost weight and regained it had lower BMRs. Their BMRs were low, despite having again reached a higher weight. Simply put, contestants were now burning fewer calories at rest even though they had more mass.

Is set point theory a factor?

Some people indicate set point theory is the reason for this inequality.Set point theory posits everyone has a “normal” weightthe body is “set” to. This relies on DNA, genetic effects, and environmental influences.

(Video) Starving Yourself to Lose Weight

Thus, when trying to lose weight, the body works hard to maintain that weight, despite extreme measures. One way it does this is by slowing the metabolism, or rather decreasing BMR, and increasing hunger. Furthermore, once a person returns to a normal calorie range they can often experience collateral fattening, where the weight loss drives overeating to the point of regaining fat.

Weight loss causes the body to focus onweight gain because of the loss of weight to the fat-free mass. Remember, fat-free mass includes any mass on the body that does not have fat, such as the bones, organs, and lean muscle.

Because starvation leads to not only a loss of fat, but a loss of lean muscle, organ tissue, and skeletal mass, the body begins to work to regain the lost mass. This activates “collateral fattening,” which increases appetite.

Opt for safer and healthier ways to lose weight

Taking a starvation approach to weight loss is a short-term fix for a problem that requires long-term methods. However, this type of extreme caloric deficit can generate the opposite results of what you are looking for. Instead of aiding the body in dropping fat,it causes the body to catabolize lean muscle massand lean tissue and bones.

More so, this type of weight loss isn’t sustainable in the long-term. Those who choosestarvation diets typically regain most of the weightwithin only a few years. It primes your body to gain fat easier in the long term and decreases your BMR, making it harder for your body to do what it naturally does, burn calories for energy. In the long-term, your body works harder to return to the overweight state it was in before starvation.

Instead of starving yourself, opt for healthier ways to lose weight. Think of thetwofold approach to body composition and focus on fat lossandmuscle gain. Choose a healthy diet within a healthy calorie range or healthy deficit and use strength training to increase lean muscle. Eating foods in low-calories andlow fatmay seem ideal, but remember tofocus on the macronutrients.

The next time you are considering an extreme diet which may push your body into starvation, think again. Think about the negative effects it may have on your body now and in the future. At the very least, consider the likelihood that you will probably regain most of the weight that was lost. That, in and of itself, should point you to a more practical and safer approach to weight loss.


Martha Garcia is a freelance writer specializing in health & wellness, women’s topics, and travel. After experiencing several health-related challenges, she developed a passion for writing about health and making medical and scientific topics more understandable to others.

(Video) Why You’re Not Losing Fat (4 HIDDEN Mistakes You Don’t Realize You’re Making)


Can starving yourself be effective for weight loss? ›

Research shows that, while starving yourself may result in short-term weight loss, this practice can have detrimental effects on your long-term health, fat percentage, and body mass.

What happens when you starve workout? ›

The lack of energy makes you feel tired, listless, irritable and unmotivated. Trying to combine a starvation diet with a strenuous workout programme is doomed to failure, because your body will not be able to meet the demands of exercise if you don't provide it with some readily available fuel.

Does starving yourself burn fat or muscle? ›

Specifically, the body burns fat after first exhausting the contents of the digestive tract along with glycogen reserves stored in liver cells and after significant protein loss. After prolonged periods of starvation, the body uses the proteins within muscle tissue as a fuel source, which results in muscle mass loss.

What happens if you don t eat enough calories when trying to lose weight? ›

Not eating enough can stunt weight loss

Just the opposite: “Under fueling” can lead to nutritional deficiencies and derail your weight loss efforts. When you severely reduce calorie intake, the body holds onto fat and turns to muscle stores for energy, which can slow your metabolism.

Does your stomach shrink when you starve? ›

Once you are an adult, your stomach pretty much remains the same size -- unless you have surgery to intentionally make it smaller. Eating less won't shrink your stomach, says Moyad, but it can help to reset your "appetite thermostat" so you won't feel as hungry, and it may be easier to stick with your eating plan.

What helps metabolism speed up? ›

Here are 9 easy ways to increase your metabolism.
  • Eat plenty of protein at every meal. Eating food can temporarily increase your metabolism for a few hours. ...
  • Drink more water. ...
  • Do a high intensity workout. ...
  • Lift heavy things. ...
  • Stand up more. ...
  • Drink green tea or oolong tea. ...
  • Eat spicy foods. ...
  • Get a good night's sleep.
Jun 20, 2022

Is it good to exercise while starving? ›

Yes, it is OK to work out while fasting because the key to weight loss and muscle gain is not just calories and exercise, but hormone optimization. Studies demonstrate amazing benefits to intermittent fasting alone, but combining fasting with sprint training takes the benefits of each to a whole new level.

Will you lose muscle if you workout without eating? ›

Muscle burning

Exercising in a fasted state may help burn more fat, but it can also cause the body to burn muscle for fuel in addition to fat. Even if the percentage of muscle burnt is comparatively small, it can be detrimental to the long-term success of any weight- or fat-loss program.

Should you exercise when starving? ›

Working out on an empty stomach won't hurt you—and it may actually help, depending on your goal. But first, the downsides. Exercising before eating comes with the risk of “bonking”—the actual sports term for feeling lethargic or light-headed due to low blood sugar.

Which part of body loses fat first? ›

Mostly, losing weight is an internal process. You will first lose hard fat that surrounds your organs like liver, kidneys and then you will start to lose soft fat like waistline and thigh fat. The fat loss from around the organs makes you leaner and stronger.

What organs shut down first when starving? ›

The body attempts to protect the brain, says Zucker, by shutting down the most metabolically intense functions first, like digestion, resulting in diarrhea. "The brain is relatively protected, but eventually we worry about neuronal death and brain matter loss," she says.

How long does it take for your body to go into starvation mode? ›

When a person has been eating a low-calorie diet for long enough to actually be starving—there's no specific caloric threshold or length of time for this to happen because it's so individual, the experts explain, but it certainly takes longer than a day without food—a few physiological processes take place.

What happens if you eat too little when trying to lose weight? ›

Lummus says that when your body goes into starvation mode, your metabolism slows to a crawl, burning calories as slowly as possible to conserve its energy stores. This is why people who cut their calories too much may reach a plateau and stop losing weight.

How do I know if my body is in starvation mode? ›

Here are nine signs that you're not eating enough.
  1. Low Energy Levels. Calories are units of energy your body uses to function. ...
  2. Hair Loss. Losing hair can be very distressing. ...
  3. Constant Hunger. ...
  4. Problems Trying to Get Pregnant. ...
  5. Sleep Issues. ...
  6. Irritability. ...
  7. Feeling Cold All the Time. ...
  8. Constipation.

What happens if you eat less than 1200 calories daily? ›

A 1,200-calorie diet is much too low for most people and can result in negative side effects like dizziness, extreme hunger, nausea, micronutrient deficiencies, fatigue, headaches, and gallstones ( 23 ). Furthermore, a 1,200-calorie diet can set you up for failure if long-term weight loss is your goal.

Why does your belly bloat when you starve? ›

To understand the reasoning for this, it is important to know that in malnourishment, the rounded abdomen is not due to fat accumulation. Instead, the water retention and fluid buildup in the body cause the abdomen to expand. This results in a bloated, distended stomach or abdominal area.

Does your stomach bloat when you starve? ›

"When we are hungry or when our bodies anticipate food, our bodies produce stomach acid, which is necessary to absorb the nutrients," Lal explained. "When there is stomach acid but no food, that stomach acid can produce gas which can, in turn, lead to bloating."

What are the side effects of not eating all day? ›

If a person continues not to eat, they can have slurred speech, confusion, syncope (fainting), or seizures. Prolonged lack of nutrition can lead to severe weight loss, fatigue, depression, and stomach issues.

Why am I gaining weight when I barely eat? ›

Unintentional weight gain occurs when you put on weight without increasing your consumption of food or liquid and without decreasing your activity. This occurs when you're not trying to gain weight. It's often due to fluid retention, abnormal growths, constipation, or pregnancy.

How do I reset my metabolism to lose weight? ›

Here are 9 easy ways to increase your metabolism.
  1. Eat plenty of protein at every meal. Eating food can temporarily increase your metabolism for a few hours. ...
  2. Drink more water. ...
  3. Do a high intensity workout. ...
  4. Lift heavy things. ...
  5. Stand up more. ...
  6. Drink green tea or oolong tea. ...
  7. Eat spicy foods. ...
  8. Get a good night's sleep.

Do you burn calories when starving? ›

“When you starve yourself, your body goes into survival mode,” said Karah Stanley, registered dietitian with St. Elizabeth Physicians Weight Management Center. If the body perceives it's being starved and doesn't have food to turn into energy, it continues to hoard fat, rather than burn it, in case food isn't coming.

Does fat burn when hungry? ›

The onset of hunger is the moment our fat stores become available for burning and is the beginning of losing fat, which is what we want! Of course, we can quickly put that stored-fat burning to an end by eating something to make our hunger go away.

Does working out hungry burn fat? ›

"There's a belief that when you exercise on an empty stomach, your body burns fat for fuel instead of the food you've just ingested," explains lead researcher Brad Schoenfeld, Ph. D. "But there's no evidence to support that fasted cardio has any benefit for fat loss."

What happens if I lift weights but don't eat enough protein? ›

Lifting and doing strength training without adequate nutrition, especially without enough protein, can actually lead to loss of muscle tissue. Furthermore, if you aren't eating right you won't have the energy to do the workouts that lead to muscle gain.

What happens to your muscles when you stop eating? ›

During the first 24 hours without food, as your glucose storage is depleted, your body will begin to convert glycogen from your liver and muscles into glucose. By the second day without food, your glucose and glycogen are depleted. Your body will begin to break down muscle tissue to provide energy.

What are the stages of losing weight? ›

The 4 Phases of Weight Loss
  • Phase -1 – GLYCOGEN DEPLETION. Glycogen Depletion: ...
  • Phase -2 – FAT LOSS. This is the sweet spot for healthy weight loss. ...
  • Phase -3 – PLATEAU. ...
  • Phase -4 – METABOLIC RECOVERY. ...
  • All the Phases of Weight Management:
Apr 12, 2018

What is the first step of losing fat? ›

Step 1: Make a commitment.

Making the decision to lose weight, change your lifestyle, and become healthier is a big step. Start by making a commitment to yourself.

What are the early stages of weight loss? ›

The first stage of weight loss is when you tend to lose the most weight and begin to notice changes in your appearance and how your clothes fit. It usually happens within the first 4–6 weeks ( 1 ). Most of the weight loss in this stage comes from carb stores, protein, and water — and to a lesser extent, body fat.

What is the body's highest priority during starvation? ›

Starvation. When the body is deprived of nourishment for an extended period of time, it goes into “survival mode.” The first priority for survival is to provide enough glucose or fuel for the brain. The second priority is the conservation of amino acids for proteins.

What hormones are released during starvation? ›

Our results support the following sequence: (1) Starvation lowers blood glucose; (2) glucose-sensing neurons respond by activating sympathetic neurons; (3) norepinephrine, released in the stomach, stimulates ghrelin secretion; (4) ghrelin releases GH, which maintains blood glucose.

Can starving cause permanent damage? ›

Starvation is a severe deficiency in caloric energy intake, below the level needed to maintain an organism's life. It is the most extreme form of malnutrition. In humans, prolonged starvation can cause permanent organ damage and eventually, death.

Why am I not losing weight on 1,000 calories a day? ›

The diet doesn't have enough calories

Eating too little — say, 1,000 calories a day — can prevent you from losing weight, too. "When you don't eat enough, your body is starving and it's not going to lose any extra weight" because it needs those energy stores to keep you alive, Fakhoury said.

What happens after a week of starvation? ›

A person's liver metabolizes fatty acids into ketone bodies that can be used as a source of energy. After approximately a week of fasting, a person's brain starts to use ketone bodies, as well as glucose, for sources of energy. Proteins not essential for survival are used first.

How many calories a day is starvation? ›

Starvation calories are an intake of fewer than 600 calories per day, however; any caloric intake below the recommended minimum doesn't provide the body with the fuel it needs to function properly. A starvation diet doesn't promote weight loss because your metabolism slows down in response to low caloric intake.

Does eating too little slow down your metabolism? ›

Eating too few calories can cause a major decrease in metabolism. Although a calorie deficit is needed for weight loss, it can be counterproductive for your calorie intake to drop too low.

Does eating too few calories slow metabolism? ›

1. It Can Lower Your Metabolism. Regularly eating fewer calories than your body needs can cause your metabolism to slow down. Several studies show that low-calorie diets can decrease the number of calories the body burns by as much as 23% ( 8 , 9 , 10 ).

Will I lose weight eating 1200 calories a day without exercise? ›

Therefore, individuals who cut their daily intake to 1,200 calories can expect to lose some weight. This can be beneficial for people who are overweight or obese. Some research suggests that a low calorie diet, such as a 1,200 calorie diet, offers additional health benefits.

How do I stop my body from storing fat? ›

Sugar and refined carbs are the main culprits here. So, if you want to decrease the amount of fat your body stores, you'll need to reduce or avoid sugars and refined carbs and replace them with vegetables, fruits, and whole grains.

Why am I not losing weight in a calorie deficit and working out? ›

If you're not losing weight in a calorie deficit you may need to adjust your stress levels, diet, and sleep patterns. Other reasons for weight gain during a calorie deficit are hormonal changes, aging, and other health conditions.

What is the minimum calories per day to lose weight? ›

A good rule of thumb for healthy weight loss is a deficit of about 500 calories per day. That should put you on course to lose about 1 pound per week. This is based on a starting point of at least 1,200 to 1,500 calories a day for women and 1,500 to 1,800 calories a day for men.

What is the minimum calories to lose weight? ›

In order to lose at least a pound a week, try to do at least 30 minutes of physical activity on most days, and reduce your daily calorie intake by at least 500 calories. However, calorie intake should not fall below 1,200 a day in women or 1,500 a day in men, except under the supervision of a health professional.

Can I eat too little calories to lose weight? ›

Our bodies need sufficient calories to function properly, and it's definitely possible to eat too few of them — even when you're trying to lose weight. Reducing calories too drastically for too long can actually derail your efforts to slim down, and even cause health problems.

How do you know if you are eating too little calories to lose weight? ›

5 Signs You're Eating Too Little For Weight Loss

How many calories a day is too little? ›

However, calorie intake should not fall below 1,200 a day in women or 1,500 a day in men, except under the supervision of a health professional. Eating too few calories can endanger your health by depriving you of needed nutrients.

What happens if you eat too little calories? ›

It Can Cause Fatigue and Nutrient Deficiencies

Regularly eating fewer calories than your body requires can cause fatigue and make it more challenging for you to meet your daily nutrient needs. For instance, calorie-restricted diets may not provide sufficient amounts of iron, folate or vitamin B12.

Why am I getting fat when I don't eat much? ›

Your Slow Metabolism:

When you have a slow metabolism, your body doesn't convert food into energy in sufficient quantities. So most of the food you eat is stored in the form of fats. This is the main reason why some people get fat even though they don't eat much.

Why am I gaining weight when I'm eating less and working out? ›

You've gained muscle.

And here's an often overlooked fact: Muscle tissue is more dense than fat tissue. So as you gain more muscle and lose fat, you change your overall body composition, which can result in a higher weight, but a smaller figure and better health.


1. What Happens if You Eat NOTHING for 3 Days
(Gravity Transformation - Fat Loss Experts)
2. What Happens Inside Your Body When You Burn Fat
(Gravity Transformation - Fat Loss Experts)
3. No Carbs for 14 Days - What Happens in Your Body?
(Thomas DeLauer)
4. How to Lose Fat AND Gain Muscle at the Same Time (3 Simple Steps)
(Jeremy Ethier)
5. There are ONLY 3 Ways to Lose Weight - Which One Will You Do?
(Dr. Becky Gillaspy)
6. Intermittent Fasting: Starve Your Fat Cells (Not Yourself)
(Dr. Becky Gillaspy)
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