24 hour fast

24 hour fast: beginners guide complete

Intermittent fasting can be done in various ways. 24-hour fast is one of my favorite fasting routines. I have done 24-hour fast alternate days of the week, which is 3 days a week.

24-hour fast is the most potent way to do intermittent fasting, also called as “OMAD Diet” (One meal a day Diet ) or “Warrior Diet”. 24-hour fast provides a sweet spot in fasting, to achieve best results and avoiding common drawbacks. (Study. 1)

What is 24 hour fast?

  • 24 hour fast means no eating for consecutive 24 hours.
  • 24 hours fast is a bit on the tougher side. In 24 hour fast, you may have several occasions where your body tells you to have some food, it’s up to you to decide that we are really hungry.
  • In 24 hours fast person can have meal at end of 24 hours, which can be breakfast, lunch or dinner.

for example,If you had lunch today, your next meal would be lunch tomorrow. One can do 24-hour fast every day or every alternate day or whatever days in a week you are OK with.

Below is sample schedule for 24 hours fast for a week

24 hour fast






What is 24-hour water fast?

In “24-hour water fast” you are not allowed to eat or drink anything except water. Benefits and results of “24-hour water fast” are similar to “24-hour fast”.

Water fast reduces the risk of chronic diseases, lowers inflammation, and lowers blood pressure. You can read more about benefits here.

What 24-hour fasting does?

not eating for a day

  • In 24-hour fasting person don’t have food for 24 hours.
  • An average person needs 1800 to 2400 calories per day.
  • Body holds around 400 to 600 grams of glycogen, which is a form of carbohydrates used as energy. 1 gram of glycogen provides 4 calories, so total caloric store of body is around 1600-3600 calories.
  • In absence of food, all this glycogen used up by the body to get energy for daily activity. When Glycogen stores exhausted, the body starts producing energy from stored fat in form of ketones. Stage, when the body gets energy from ketones, is called as ketosis.
  • 24-hour fast push body in ketosis, how early or how much time all depends on persons daily activity levels. A person doing exercise on fasting day may get into ketosis early compared to a sedentary person without exercise.

24 hour fast benefits

Fasting has multiple benefits to a modern human who spends most time seating on a chair and eating 3-6 times a day.

24 hour fast benefits


  • Ketosis occurs when glycogen stores in the body are exhausted, and the body starts burning fat for energy. Ketones are generated from fat which is used by the body to fuel the brain and other important organs. [Study 1,2]
  • Ketones are super fuel for the brain. People experience intense focus and productivity.[Study 3,4]


  • Autophagy is a cell-recycling process. As persona age body accumulates a lot of damaged or broken cells. These cells can lead to various problems like cancer .
  • In absence of food, body speeds up the process of cell recycling in which damaged cells are used up for energy. These damaged cells are replaced by new functioning cells. (ref. 5,6,7)

Weight loss

  • The most visible benefit of “24-hour fast” is weight loss. The body needs plenty of water for food digestion. As no food intake happens body excretes water through urine. A person in 24-hour fast also burns glycogen and fat stored in the body.
  • Combining exercise with fasting is the most effective way to lose weight.
  • A person can lose on average to 2 pounds (1 kilogram) per day. Out of which 20% to 25 % weight loss is fat loss and rest is water weight. [Study 8,9,10,11]

Improved blood sugar levels

  • The body has natural ability to control blood sugar by insulin secretion. As we age body needs more insulin to control blood sugar, which is  also called as “insulin resistance” and a major cause of Type 2 Diabetes.
  • in 24-hour fast no food intake happens, hence no insulin secreted. This on and off in insulin secretion improves insulin sensitivity. if done long-term one can reverse type 2 diabetes. (Study 12,13,15)

You can read more about 24-hour fasting benefits here

What to eat or drink?

24 hour fast

  • Drink plenty of water, have tea or coffee without sugar as much as you like .
  • During fasting avoid snacks and sugary drinks.
  • Do not user artificial sweeteners.
  • When breaking fast try to add more nutrient-dense foods. More vegetables with salad. Add some fats like olive oil, butter or pure ghee. Add Eggs as it is a good protein source. Consume less meat or seafood.

You can read more about what to eat or drink here.

Are there any drawbacks of 24 hour fast?

  • Initially one can experience increased hunger, bloating, indigestion. These problems will fade away after some days.
  • Short-term symptoms like a headache, dizziness may occur these too will go away after some experience in 24-hour fast.
  • Some people will experience low sexual drive and may affect fertility. However, on a normal day’s sexual drive returns to normal.

Who can do 24-hour fast?

  1. Any person above 18 age, with no existing medical condition, can do a 24 hour fast.
  2. People with medical conditions should consult a doctor before starting with a 24 hour fast.
  3. Malnourished people, a pregnant or breastfeeding woman, children under 18 age should avoid doing any kind of fast.

Is 24 hour fast every day good idea?

  • Yes, it’s possible to do 24-hour fast every day of the week. You will experience extreme weight loss in a short time. One can lose around 2 pounds a day which means 10-12 pounds in a single week.
  • However such extreme weight loss not recommended in such a short time.
  • Have one meal in a day on every day of the week, and stop doing it after your target weight achieved.

What is “5-2 diet” and its benefits?

  • Fasting for any 2 days in a week called as “5-2 diet”.  2 days can be consecutive or any random days in a week.
  • Benefits are similar to 24 hour fast like weight loss, reduced inflammation, reduced risk of chronic diseases, normal blood pressure

Read more about benefits here.

Autophagy and loose skin

24 hour fasting results

  • A person who loses a lot of weight, in short time struggles with loose skin.
  • In autophagy body uses its damaged or broken cell for providing energy to vital organs. Autophagy speed is proportional to fasting time, more time you are in fasting mode, more the autophagy speed.
  • Loose skin is also a form of unneeded cells, during autophagy body start using the loose skin for energy and after some time person get rid of loose skin. Usually, a person needs to have surgery to remove such excess skin but by fasting, an extended period body gets rid of loose skin on its own.
  • 24 hour fast provides most benefits with least amount of negative effects, it is also a popular way of fasting. If you have any queries please feel free to ask in comments

if you have any question please ask in comments below.

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  1. lets say I tried this 24-hour fast, i have been drinking plain water in between, does it still count or is it already considered 24-hour water fast? Is it really possible to lose 8kg in a week?

    1. Drinking plane water don’t break fast, drink water when you like.
      If you are new to fasting start with short period like 16/8 fasting.
      1 Kg per week is good for body and overall health.
      It’s not possible to lose 8 kg in week, any kind of extreme weight loss should be done under medical supervision.

  2. I tried intermittent fasting twice a week for a couple months and my thyroid started acting out, so I stopped. Should I try 24 he fasting (say once a week or once a month) or shall I expect the same cons?

    1. First consult with your doctor, then under his super vision start with 16/8 fasting single day in a week.
      If you are new to fasting start with skipping a single meal for few days in week. Let your body to adapt with changes, When you are comfortable start 16,24 or more hours fasting.
      Remember let your body to adapt with changes it may take months.

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