What is the 5:2 Diet?

The 5:2 diet is a simple diet regimen that involves eating anything you want for 5 days in a week, and restricting calorie consumption to 25% of normal intake on the remaining 2 days of the week.

Consumption of one-fourth of normal calories is equivalent to about 500 calories for women and 600 calories for men for 2 days of the week. These 2 days should not be consecutive days.

5:2 fasting diet concept. Image Credit: Ekaterina Markelova / Shutterstock
5:2 fasting diet concept. Image Credit: Ekaterina Markelova / Shutterstock

Fasting days

The 2 days during which calorie intake is restricted are known as fasting days though there is no actual fasting. It is just limiting calorie intake to one-fourth of the body’s energy needs. It is not recommended to fast on 2 consecutive days; most dieters arrange fasting days to follow a Tuesday and Thursday schedule or something similar. Breaking up fasting days helps manage hunger pangs, which can be tough during the initial few weeks of the diet. Dieters can choose to fast on different days each week based on their other personal or professional plans. Some people even move to a 6:1 diet once they have achieved their desired weight.

On fasting days, dieters eat 2 to 3 small meals. There are no specific food restrictions if dieters stay within the calorie limits. Following this diet, women may lose up to a pound per week, whereas men may lose even more.

What to expect on fast days?

During the first few weeks, people tend to feel very hungry on fast days, but the pangs should pass quickly. Healthy snacking and keeping oneself engaged help with these symptoms. There have been reports of headaches and cold sensitivity among dieters. Forh most people, these discomforts are much easier to manage after the first 2 weeks.

Intermittent fasting diets are safe for most dieters, though it is worth taking it slow and closely observing how your body reacts to fasting during the first week. In you feel unwell or faint, do not hesitate to break your fast and consult your physician before re-starting a fasting diet.

The author of the 5:2 diet explains why eating healthy is more important than exercise

Eating smart on fast days

Although dieters can eat anything they want and there is no restriction to the type of food they eat, they are encouraged to eat wisely to keep hunger at bay and lose weight effectively. Dieters should include low-calorie foods with a lot of fiber to keep them feeling full longer. Examples of foods that are filling and nutritious are:

  • Fresh vegetables, especially greens
  • Eggs, lean meat, and fish that are roasted or baked, not fried
  • Warm soups in winter and salads with herbs in summer
  • Plenty of fluids in the form of water, black tea, or coffee

Foods to avoid on fasting days:

  • Processed carbohydrate-rich foods such as white rice, pasta, and bread
  • Sugary foods and fruits
  • Drinks with added sugar
  • Milk, as it can add to your calorie intake

Eating on non-fasting days

Although you can eat anything you want on the 5 non-fasting days, it makes sense to eat wisely and be mindful of one’s calorie intake on these days as well. Although fasting twice per week will decrease calorie consumption by 3,000 to 3,500 calories, the equivalent of 1 pound, each week, overeating on the other 5 days will nullify this weight loss effect.

Tracking weight loss

Dieters are told to weigh themselves on Day 1 of the 5:2 diet, and to measure hip, chest, and waist circumference as well. The measurements should be repeated at the same time every week. The rate of weight loss will depend on several factors, such as age and activity level. It is important to have realistic expectations and not compare one’s rate of weight loss with that of others or become disappointed if weight loss is slow.

Weight loss tends to be faster initially, especially for those who were overweight. Also, factors such as hormonal activity and metabolism can result in several pounds of weight fluctuation despite a slow and steady loss of fat.

Who should avoid this diet?

People in these groups should not fast or diet without first consulting with their physician:

  • Pregnant women
  • Nursing mothers
  • Children or teenagers
  • Persons with eating disorders
  • Persons with diabetes
  • Persons with acute or chronic medical problems

Further Reading

Last Updated: Apr 6, 2023

Susha Cheriyedath

Written by

Susha Cheriyedath

Susha has a Bachelor of Science (B.Sc.) degree in Chemistry and Master of Science (M.Sc) degree in Biochemistry from the University of Calicut, India. She always had a keen interest in medical and health science. As part of her masters degree, she specialized in Biochemistry, with an emphasis on Microbiology, Physiology, Biotechnology, and Nutrition. In her spare time, she loves to cook up a storm in the kitchen with her super-messy baking experiments.


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