Is Intermittent Fasting Always Healthy? Know About 6 Demerits Of This Diet Plan

Intermittent fasting is a very trending diet plan but it has its disadvantages as well. Read to know demerits of this diet.

Puru Bansal
Written by: Puru BansalUpdated at: Dec 07, 2021 12:05 IST
Is Intermittent Fasting Always Healthy? Know About 6 Demerits Of This Diet Plan

3rd Edition of HealthCare Heroes Awards 2023

Intermittent fasting is one of the most worked out fasting schedules because it allows people to have a pattern of eating. However people have started following it without recommendation from any expert dietician, this creates negative effects on health of the people and hence it needs to be avoided. Those who do not know, intermittent fasting is a type of dieting plan where you have food in time interval of 6-8 hours and fast for rest of the day. Different individuals have variety of variation which affects their health. Today we are going to discuss about demerits of doing intermittent fasting and side-effects it has on people. 

Why does Intermittent Fasting Cause Side Effects?

Side effects or demerit of intermittent fasting depends on every individual. Since some people have food at odd times and remain on fasting for rest of the time, it gives them headaches, bloating, nausea and many more problems. According to Clinical Nutritionist Ms. Shilpa Singh from Fatima Hospital, Lucknow, most of the people who follow this diet plan do periodic fasting. Not everyone’s body can take up this diet plan hence you should not force it on yourself. Also there is a particular diet which you need to have so that the nutritional demands are fulfilled. If this does not go as planned then side-effects tend to occur.


People suffering from some underlying health conditions are very likely to have side-effects of this diet. Individuals having these problems should especially be aware of-

  • Lower blood pressure
  • Diabetes
  • Insulin sensitivity
  • Heart disease
  • Suffering from oxidative stress or chronic stress

Disadvantages of Intermittent Fasting

Demerits and disadvantages of intermittent fasting depend on the type of side-effect you have. Here are some common problems associated with intermittent fasting that you must know. 

1. Headaches 

Headaches are very common signs that reveals that your body is not responding well to the given diet plan. Headaches typically occur in the first few days of fasting protocol. You may have headaches because body is unable to cope up with the changes and routine it follows. There have been many studies in which people following this diet have reported of headaches and light headedness in the morning. This is because of such a long break, lack of nutrients, nerves give signals to brain that there is immediate need of fiber or deficient nutrients in the body.


2. Digestive Problems

After going on intermittent fasting, you may not follow a regular diet given by the dietician, this causes indigestion. Indigestion in stomach ruins your fasting routine and becomes more harmful than proving beneficial for the body. Especially with people that are on intermittent fasting for losing weight, it becomes particularly challenging. 

Reduction of food intake result to following problems-

Among these problems, dehydration and constipation is most common because people forget to have adequate amount of water during the fasting hours. Chance in diet routine is also a big factor; sometimes your body is not able to cope up with dietary changes and gives signals of indigestion. For eradicating this problem, choosing right nutrient diet and having more water in your diet is important.

Also Read- Know About 5 Winter Eye Problems That Are Common In The Cold Season

3. Irritability and mood changes

This is very common in following any particular diet plan. This is because to switch to one particular types of food that makes you irritated over period of time. You always try to have variety in your food which you are unable to get resulting in mood swings and changes in mood. When blood sugar is low, then it could be particularly problematic because mood swings are on the peak and you may break the dietary norms set for you. It becomes more evident in non-fasting period where your body craves for some changes and favorite foods.


4. Causes fatigue

This occurs as a side-effect when the intermittent fasting is not followed well. Another cause could be having more physical workout and fewer calories in the day. Fatigue is very common in the starting or with people that have more physically challenging jobs. Low energy levels and feeling tired is common in this diet plan because calorie intake is very limited and thus results to sleep disturbances. Fatigue and low energy levels in body is one of the common side-effects of intermittent fasting.

5. Bad Breadth

This is an unpleasant side of being in intermittent fasting. This remains for the fasting period because salivary flow of acetone in breadth becomes evident. The only way to get rid of this is through having more water intake and having some mouth fresheners if possible. Bad breadth could last long and become a devil for you in following your social routine. 

Bad breath usually occurs because of burning of fat in body. It is also an result of metabolism process in the body during fasting hours.

Also Read- Beware Of These 6 Demerits Before Taking Steam Bath

6. Sleep Disturbances

As mentioned earlier, due to various reasons intermittent fasting can cause sleep disturbances. it is because you are unable to stay asleep while you are hungry and fasting. People who develop this fasting regime are able to cope up and have regular sleep but their sleep cycle may be affected. This means that they are also probable to get less sleeping hours than usual. 

Around 15% people following intermittent fasting diet routine have complained of sleep disturbances of different kinds. It could also be because of large amounts of salt and water through urine.

Picture Credits-