Written by Andrew Brewer. ⚕️Reviewed and fact checked by our medical team.


Millions of people all over the world have weight loss goals, and many will go to dangerous extremes and use untested methods in order to achieve them. While drastic, rapid weight loss is incredibly appealing, especially in a world that values instant gratification, ultimately, it is extremely unhealthy in the long run and can have both short-term and long-term side effects. For a long term results we recommend you reading our how to lose weight fast but safe guide.

Key Takeaways

  • Drastic weight loss can have both short-term and long-term side effects, and it is not a healthy or sustainable approach to weight loss.
  • Weight loss methods such as starvation diets, supplements, and excessive exercise can be dangerous and have not been proven to be effective for long-term weight loss.
  • Loose skin and gallstones are two of the potential side effects of rapid weight loss, and surgery may be required to address them.
  • Detox diets are not necessary for a healthy body as the liver and kidneys are responsible for removing toxins from our bodies.
  • To lose weight safely and effectively, it is recommended to follow a balanced and healthy diet and engage in regular exercise.

Drastic Weight Loss Definition


Drastic weight loss refers to when an individual loses large amounts of weight over a comparatively short period of time. You may have seen products that guarantee to help you “lose one dress size a day”, “lose ten pounds in a week”, and “melt body weight/fat away almost instantly, like magic.” What they are advertising here are products that will supposedly cause you to lose a lot of weight very quickly.

Weight Loss Methods

Many of these widely advertised products are the bane of almost every legitimate health professional—dubious, barely-tested formulas (that do not have to be approved by the FDA) developed into weight loss aids and marketed by an industry that operates with shockingly little oversight.

Starvation diets

Also known as “cleanses” or “fasting”, these methods prescribe an extremely limited diet, such as only consuming one type of food or one specific combination of ingredients, such as cayenne pepper, water, maple syrup, and lemon juice. These have been around for decades and have existed in countless variations and have often been advertised as a way to “detoxify” the body. Now, these products do actually cause you to lose weight if you stick to the program. But your body cannot survive on a diet like that because it does not contain all of the vital nutrients that it requires. Once the cleansing or fasting ends, and you resume your regular eating habits (in many cases, the first thing people do when they end these diets is to binge eat, which causes more weight gain) and any weight that you had lost comes right back.

Also, for on those who think following certain diets will “detox” their body. That word “detox” sounds so appealing—after all, we’re constantly opposed to pollution, additives, chemicals, so why wouldn’t detoxification be a good thing? Well, it is a good thing, and your body knows it. That’s why we have kidneys and a liver; their major function is to remove toxins from our body. As long as those two organs (and presumably, the rest of you) is functioning properly, you do not need to detox—you just need to maintain the health of your organs. Additionally, if your kidneys and liver are not functioning properly, then drinking lemon juice for a week won’t cure it.


There is no miracle pill for weight loss. Dietary supplements do not need FDA approval before being marketed to consumers; in most cases, they have not been tested for safety and they are not required to prove that their product works as they advertise. The dietary supplement industry is very unregulated in the United States to the point that the ingredients listed and/or shown on the bottle are not always even present inside the actual product. Unsafe dietary supplements have caused hundreds of deaths over the years and even more adverse events. Using them as a way to experience drastic weight loss is a risk and a waste of money as well, as most do not work as they claim.

Very low calorie diets & excessive exercise

These are extreme versions of the controlled diet and healthy amount of exercise that everyone should be following. And, unlike the products described above, they can actually cause you to drop a drastic amount of weight in a very short amount of time.

Very low calorie diets usually prescribe calorie amounts that are below 1000. Some studies have used 500 calorie diets as a representative for a VLCD, but the amount really varies depending on the person doing the diet and the program that they are following. Excessive exercise sometimes goes along the VLCD, though that does depend on the person, as some people think that cutting a lot of calories means that they do not have to exercise, while others do both. On its own, excessive exercise can cause depression, fuel eating disorders, injuries, and exhaustion.

Side Effects of Rapid Weight Loss


Loose skin

Loose skin does not cause any serious medical problems, but it can be distressing. Imagine—you have finally lost all of the weight you wanted to loose, but you still have loose, baggy skin instead of the lean and taut body that you worked so hard to achieve. Loose skin due to weight loss occurs because the skin has lost some of its elasticity and it does not shrink at the same rate as that at which you lose weight. The effect can be disheartening and cause uncomfortable chafing. Sometimes the loose skin will re-tighten and form back as it should be, but, often, surgery is required if an individual wants to get rid of it.


Gallstones are hard deposits in the gallbladder, an organ that stores bile which is needed for food digestion, and can be as small as a grain of sand and as large as a golf ball. Most gallstones, about 80%, are made of cholesterol (these are called “cholesterol stones”; the other 20% are made of bilirubin and are known as “pigment stones.”

  • Cholesterol stones

Cholesterol stones form when your liver produces too much cholesterol (their formation is not linked to blood cholesterol levels). Usually, the bile in the gallbladder breaks down and dissolves cholesterol, but when there is too much of it, it builds up and forms gallstones.

  • Pigment stones

Bilirubin is produced when the liver destroys old red blood cells. Overproduction of bilirubin by the liver, often caused by cirrhosis and some blood disorders, results in the gallbladder being unable to break down the excess bilirubin.

Risk Factors

  • Being overweight or obese
  • Consuming a diet that is high in fiber
  • Rapid weight loss over a short period of time
  • A high fat or high cholesterol diet

Looking at the risk factors, we notice that two of them are 1) too much weight, and 2) losing that weight too quickly. Both are harmful, meaning that the latter is not the cure for the former. In fact, in most people, gallstones are not actually preventable. However, those who are overweight can lessen the chance that they will develop gallstones by losing weight gradually and safely, rather than rapidly.


  • Fever
  • Right and/or middle upper abdominal pain lasting for at least one half-hour
  • Yellowing skin and eyes
  • Vomiting and nausea
  • Stools that are color of clay.


If your gallstones are made of cholesterol, then they can usually be dissolved using medication; however, that medication can take years to totally eliminate the gallstones from your system. If you are experiencing severe systems, then surgery is the only option. Your doctor will usually perform a laparoscopic gallbladder removal, a simple procedure performed while the patient is under general anesthesia. As long as there are no complications, the patient can go home the same day.

Life without a gallbladder

Your gallbladder is not a necessary organ and you can still lead a totally normal life after having it removed. However, there are some side effects, such as loose and watery stools. After being released from the hospital, you may need to take up a liquid diet.

Loss of lean muscle

When most people say that they want to lose weight, what they typically means is that they want to lose fat. They want a muscular and toned physique in addition to a body that functions better when it is at a healthy weight. While losing weight rapidly can make you smaller, what you are losing is often not fat. It’s lean muscle—something that you want to keep.

A 2014 study examined the effects of two types of diets. One group was put on a very low calorie diet of 500 calories/day for five weeks; the other was put on a low-calorie diet of 1,250 calories/day for 12 weeks. At the end of the study, the scientists compared the results and found that both groups lost similar amounts of weight, on average, an amount around 19lbs, but that there were differences in what made up that amount of lost weight. In other words, they looked at the amount of fat-free mass, which, as the same suggests, is all tissue in the body—bones, blood, organs, and muscles—except for fat. The masses of the first three do not change when you diet, so essentially, the scientists were examining the amount of muscle mass lost. Those on the low-calorie diet lost about 1.3lbs of fat-free mass, but the individuals who ate the very low calorie diet for five weeks lost 3.5 pounds of fat-free mass.


To understand lean muscle loss and why it is so dangerous, it is key to understand several basic fundamentals about bodily mechanics. A certain number of calories is required to make your body work as it is intended; this includes everything from digestion to breathing to being able to move. The number of calories that your body requires to do these things is called its basal metabolic rate, and that number differs from individual to individual. Weight loss occurs when you burn and/or consume fewer calories than your body requires for its current weight.

If you do not consume as many calories as your body requires, it still needs energy, so it starts using stored energy. The body’s preference for energy sources is: incoming calories, then stored fat, and then muscle. When you want to lose weight, you want your body to burn the first two, not the third. However, while we see losing weight as something positive, our body does not always agree. It has evolved a mechanism to guard against starvation; when your body thinks that it is starving, such as when you begin to lose a lot of fat over a short period of time, its main goal is to make sure that you survive, so it slows your metabolism and becomes incredibly efficient. It tries to preserve its fat stores which forces it to turn to its last energy source—muscle. If you run out of fat and muscle, the body will start to metabolize your organs in order to maintain your brain’s functionality.

The consequences of losing muscle

Muscle plays a large role in your metabolic rate (the rate at which you burn calories); less muscle causes a reduction in your metabolic rate, which means that, when you eventually begin to eat like you normally do, your body will gain weight quicker than it did before you lost the weight. Losing muscle through dieting essentially means that you are handicapping the rest of your bodily functions that require a strong muscular system to operate. You won’t have as much energy, you’ll feel weaker, and your quality of life will generally be poorer. Generally speaking, the consequence here muscle atrophy. The best way to lose weight while maintaining muscle is to combine calorie restriction with strength training.

Nutrient Loss/Malnutrition


This particularly applies to individuals on very low calorie diets and it can have serious and profound effects on the health of those affected by it in both the short-term and long-term. Because nutrients are what your body requires to power, strengthen, and maintain your body, the list of consequences can get extremely long, depending on the nutrients in which you have deficient levels.

  • Weaker immune system that leaves you more prone to infection and illness, and that makes it harder for you to recover from such ailments.
  • Loss of bone density, which can eventually cause osteoporosis and increase the risk of breaking bone.
  • Headache, fatigue.
  • Brittle hair and nails. It can actually cause hair loss.
  • Nervous system damage, which is a long term effect that can affect the body in a multitude of ways, impeding one’s sensory abilities (sight, hearing, etc.), movement, balance, coordination, blood pressure and flow, and one’s mental abilities.

Weight Re-gain

We’ve hit on this a few times, but it’s important enough to warrant its own section. If the goal you have set is to lose weight and you achieve that, the last thing that you want to happen is for all of that weight to come back, probably bringing friends along with it. Weight re-gain is possible with any diet or exercise plan, but it is particularly common with those who lose weight drastically and quickly. Here are a few reasons why:

  • Those methods that cause quick, drastic weight loss are rarely sustainable, causing people to go back to their unhealthy habits almost immediately.
  • Certain methods that slow your metabolism cause you to gain weight more quickly once you have fallen off of the diet wagon.
  • Hormonal changes cause to feel hungrier, so you eat more, eventually regaining all of your weight.

Perhaps the worst part of weight regain is that it is part of a never-ending, vicious cycle that we colloquially refer to as “yo-yo” dieting. An individual loses a large amount of weight, keeps it off for a few months or weeks, and then gains it all back plus some. Then, he/she goes on another diet, loses the weight, then it all comes back. And over and over, the cycle repeats. Not only does this wreak havoc on your closet and self-esteem, it is actually extremely hard on your body and can actually change your physiology.

  • The rapid weight loss-gain cycle increases your risk for cancer, diabetes, and heart disease.
  • It causes arterial damage, due to the frequent growing and shrinking of arteries as you gain and lose weight.
  • It can have psychological effects, as regaining weight makes you feel disappointed in yourself and cause you to think of yourself as a failure, not to mention the effects of body image issues.
  • Yo-yoing causes you to regain excess fat each time you start to gain weight again. Also, as mentioned previously, the extremely low-cal diets that are typically common in a yo-yo dieter’s life can also cause muscle wasting. The combination means that you are going to be losing muscle, and gaining fat, both of which are harmful to the body. This can lead to coronary artery disease and diabetes, which comes with its own terrible side effects.
  • Limits brain functionality and increases fatigue and irritability.


Drastic, rapid weight loss, while appealing, ultimately wreaks havoc on your body. It’s a hard truth to here, but if you’ve been living an unhealthy lifestyle for years and years, you will not be able to quickly repair the damage within a few months. Can you take off large amounts of weight quickly? Yes, but there are so many consequences, large and small, short-term and long-term, especially if you achieve it by depriving your body of what it needs to survive.

The only time drastic, rapid weight loss is a good idea is when it is done under a doctor’s care. This occasionally happens when a doctor sees a patient who is severely suffering from the effects of being overweight or obese, presenting a problem that needs to be solved quickly. But this is done under a doctor’s supervision and under their advisement.

In all honesty, there is no miracle solution to one’s weight problems and drastic weight loss is certainly not the answer because of the myriad of health problems that it can cause both in the short-term and long-term, not to mention that the weight that is lost usually comes right back. The way to really solve your weight problems in a way that is both healthy and long-lasting cannot be found in a shady dietary supplement, juice fasting, or starvation diets. The best way to decrease your weight while giving you the best chance of keeping it off is to adopt and adhere to lifestyle changes, i.e. maintaining a healthy diet and getting plenty of exercise. The most important component of a diet and exercise plan is sustainability—is it something that you can and will do each day?

A weight loss rate of one to two pounds per week is what is considered healthy by most medical professionals. This means a total of four to eight pounds per month, although if you follow to a plan strictly, you may be able to safely push that amount to ten pounds a month. However, this number can vary depending on the person and their age, weight, current physical condition, current weight, and medical concerns. Your doctor will be able to help you decide what your ideal weight loss rate should be, as they will be able to take into account all of the variables that might affect such efforts.


  • What is drastic weight loss?

Drastic weight loss refers to losing a large amount of weight in a relatively short period, typically achieved through extreme calorie restriction, excessive exercise, or a combination of both.

  • What are the dangers of drastic weight loss?

The dangers of drastic weight loss include malnutrition, dehydration, gallstones, muscle loss, hormonal imbalances, weakened immune system, and increased risk of regaining weight.

  • What is malnutrition?

Malnutrition is a condition that occurs when the body doesn’t get enough nutrients, such as vitamins and minerals, to function properly. It can result from a lack of food or a diet deficient in certain nutrients.

  • How does drastic weight loss lead to malnutrition?

Drastic weight loss can lead to malnutrition because it often involves severe calorie restriction, which means the body doesn’t get enough nutrients to function properly. In addition, some weight loss diets eliminate entire food groups, which can lead to nutrient deficiencies.

  • What are the symptoms of malnutrition?

The symptoms of malnutrition can include fatigue, weakness, dizziness, hair loss, dry skin, brittle nails, and an increased susceptibility to infections.

  • What is dehydration?

Dehydration occurs when the body loses more fluids than it takes in. This can be caused by sweating, vomiting, diarrhea, or not drinking enough water.

  • How does drastic weight loss lead to dehydration?

Drastic weight loss can lead to dehydration because it often involves excessive exercise and/or calorie restriction, which can cause the body to lose fluids.

  • What is muscle loss?

Muscle loss, also known as muscle wasting or sarcopenia, is when the body loses muscle mass and strength.

  • How does drastic weight loss lead to muscle loss?

Drastic weight loss can lead to muscle loss because it often involves calorie restriction and/or excessive exercise, which can cause the body to break down muscle tissue for energy.

Andrew Brewer

Andrew Brewer

Andrew Brewer started to give people the guidance that he never received when he was first starting. His goal is to make your goals achievable and to offer you only the best fasting apps that the internet has to offer. You're not on your own - Andrew and the entire family of reviewers at are here with you every step of the way!