Does Fasting Help You Lose Weight? A picture of a plate with a sad face smiley, spoon and fork on a purple background.Fasting results in weight loss is a commonly held belief. You probably heard it or thought it to yourself “instead of diet, or exercise just fast and you will be fine”.
Well, while this might work in some instances, it might be detrimental to your health in other instances.

Firstly, You should understand your body’s metabolism before you embark on your fasting journey.
Secondly, You need to ask yourself what caused the extra weight gain? Is it as a result of your bad eating habits or bad lifestyle habits? If this is true, then your approach should be to correct these habits first.

In some people due to their metabolism and lifestyle choices, fasting simply won’t work. And it might be detrimental to their health.
So here you are trying to be fit and healthy and instead of doing the right thing, you’re simply hurting yourself.

In addition to hurting yourself, some people have certain conditions that aren’t compatible with fasting.
e.g. people with or that are prone to diabetes and ulcers should limit fasting and consult their doctors before fasting in order not to aggravate their health conditions further.

Besides, it might be difficult and punishing to tell an overweight or obese person to fast. Why? This is because of the hormone “Leptin” which increases the urge for food in the overweight and obese. The level of leptin is high in this group of people and sensitivity to this hormone is decreased. Usually, leptin should reduce the level of hunger and cause satiety but since sensitivity to it is decreased, the level of hunger and in-satiety increases.

How the Body Loses Weight When You Fast

The body has several ways of providing energy to keep it functioning. If one way stops working, then it relies on other ways. After eating food, the blood glucose level rises and this stimulates the release of insulin. Insulin helps push glucose into cells and store them as glycogen in the liver and muscles. When glycogen stores are filled up, excess glucose is converted to fats and they are stored in adipose tissues. This is how weight is gained.

A while after eating, the level of insulin goes down while that of glucagon and epinephrine goes up. The glycogen stores are broken down and glucose is released in the blood. Amino acids gotten from proteins are also released from skeletal muscles and fatty acids from adipose tissues.

In the case of Fasting, the levels of glucagon and epinephrine become very high. At this stage, glycogen stores are depleted and the break down of fats from adipose tissue occurs. This will result in weight loss.

While this might be good you think since fat break down will result in weight loss but it’s a little more complicated than that. When the fats are broken down for energy, a substance known as acetyl-CoA is released in excess and is used for ketone synthesis.

Increased ketone levels in the blood aren’t good. It can lead to ketoacidosis which as several negative effects on the body.

It is associated with symptoms such as; polyuria, dehydration, thirst, CNS depression, coma and may eventually lead to death. It has a characteristic strong ketone breath smell.

The Negative Effects of Fasting
1. Indulgence in Bad Eating Habit

There is a biological push to want to overeat after fasting. It’s a sort of compensatory mechanism your body crave for and a lot of people fall for this. This results in unwanted calories that cancel the effect of fasting and maybe dangerous since bad eating habits are addictive. So there is a likelihood you stick with these bad habits even when you aren’t fasting.

2. It’s easy to give up on

This weight loss technique is just too easy to quit compared to other techniques. It takes time to adapt to it. This is simply because the hunger hormone “ghrelin” is secreted when the stomach is empty and secretion stops when the stomach is stretched or after eating. This makes you more hungry when fasting as compared to when you aren’t.

3. Electrolyte imbalances

This might affect people with high blood pressure and heart diseases. Fasting results in an imbalance of homeostasis and important electrolytes that keep the body’s vital organs such as the heart and brain functioning properly. If you are in this category, You should consult your doctor before embarking on your fasting journey

4. The inability of the body to function properly

The body needs food to provide it with the energy it requires to function. When the body doesn’t get the appropriate energy it needs, you won’t have enough energy to carry out our normal daily activities resulting in unproductivity. Apart from that if the body doesn’t get the nutrients, it needs to function, it starts to malfunction e.g. Low immune response, slow healing etc.

5. Ketoacidosis

High ketone bodies which result from high fat breakdown will occur as a result of prolonged fasting. It is characterized by a distinct ketone smell, dehydration, thirst, dizziness, headache and may lead to coma and eventually death.

The Right Approach to Fasting

Fasting has benefits if it’s done right, suitable for you and your body metabolism. If it works for you, then at least you want to get it right.

The best technique for fasting is known as intermittent fasting. This is when you have your normal calorie intake for most days of the week and limit calorie intake during certain days of the week or during specific hours of the day.

This has been proven to work by a number of studies.

In research published in JAMA Internal Medicine, 100 overweight people were given one of three eating plans; restricting daily calorie intake by the same amount every day (similar to a traditional diet plan), fasting on alternate days, and continuing with normal eating habits. At the end of the 12-month study, both diet groups had lost weight compared with the normal eaters. However, the people on the fasting plan didn’t fare any better than those restricting daily calorie intake.

This proves that intermittent fasting works but not any better than dieting i.e. cutting caloric intake.

Alternatives to Fasting

There are several more efficient ways to lose weight apart from fasting.

 1. Have a suitable diet plan for you: From the study above, fasting doesn’t work any better than dieting. Dieting might be preferred since the negative effects are reduced. Read how to make a diet plan here.

  2. Exercise: If you are serious about losing weight, then you want to do some exercise. Your fitness is a combination of diet and exercise. You can simply start with fitness basics and you can advance from there. Make your own workout plan, choose which exercises are suitable for you. You can go to the gym or do at-home exercises.

3. Drink water more often: Water is vital for your health. Not only that, water helps you lose weight by reducing hunger. You want to drink water as often as possible. It’s recommended to take 8 cups of water per day.

4. Eat Fruits more often: Fruits are high in fibre, water, nutrients, vitamins and minerals, which are beneficial to health and weight loss. The fibre content of fruits helps digestion, fills up the stomach, reduces hunger, thereby reducing weight loss. It is recommended to eat two cups of fruit per day


So as you can see, fasting isn’t the perfect solution to weight loss. If done well, in the case of intermittent fasting, it can be beneficial to health. If not, it can be detrimental to health.

Dieting is a better alternative to fasting because you get approximately the same result with less negative risk effect.

It is also important to note that we respond differently to fasting. Some people can tolerate fasting better than others while some can’t tolerate it at all. It’s best to understand your metabolism before deciding to fast or not.

Lastly, fasting is not advised or you should consult your doctor before fasting if you have certain conditions such as stomach ulcers, diabetes, high blood pressure and heart diseases.

Dr Klas

Dr Klas aka Dr Emmanuel Adeniran is a medical doctor, a health educator, and a fitness enthusiast who has been into fitness for more than five years. He is willing to share his knowledge and experience with you.


Ruth · 3rd June 2019 at 9:28 pm

Fasting for weight loss carries other health risks as well. While fasting for a day or two is rarely a problem if you are healthy,

Marie · 4th June 2019 at 7:38 pm


Daniel · 6th June 2019 at 12:07 am


Debbie · 6th June 2019 at 9:56 am

Your body’s metabolism is often touted as the hidden secret of weight – loss success—a fast one helps you lose weight , and a slower one can work against you. But can shedding pounds actually make your metabolism slow down and turn sluggish? If you’ve hit a weight – loss plateau you may be wondering …

Annie · 9th June 2019 at 5:02 pm

Levels of electrolytes including sodium, potassium, calcium, magnesium, chloride, phosphate, and carbonate can become too high or too low. Changes in electrolyte …

ปั้มไลค์ · 13th June 2019 at 7:35 pm

Like!! Thank you for publishing this awesome article.

Alquino · 14th June 2019 at 8:17 am

What Are Electrolytes? … Loss of body fluids from prolonged vomiting, diarrhea, sweating or high fever. Inadequate diet and lack of vitamins from food. Malabsorption – your body may be unable to absorb these electrolytes due to a variety of stomach disorders, medications, or may be how food is taken in … A Minor electrolyte imbalance may be …

Julie · 14th June 2019 at 9:28 am

Electrolyte disorders are most often caused by a loss of bodily fluids through prolonged vomiting, diarrhea, or sweating. They may also develop due to fluid loss related to burns.. Certain …

Jay Deshazior · 27th June 2019 at 5:17 pm

Thansk for the blog mate

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