Intermittent fasting: effects and methods

During intermittent fasting, your usual mealtime schedule is interrupted by long periods during which you don’t eat. We explain the 16:8 and 5:2 fasting methods and also what effects intermittent fasting has – and why it doesn’t constitute a diet.

13.03.2023 Daniela Schori 4 minutes

Fasting means either partially or completely going without food and stimulants for a certain period of time. There are different forms of fasting.

In recent years, what is known as intermittent fasting has gained public attention. This involves combing eating at regular time intervals with recurring periods of fasting. The aim of intermittent fasting is to maintain a regular weight in the long term.

Intermittent fasting: a guide and methods

5:2 method – fasting for two days

One common form is the 5:2 method. For five days, you eat as you would normally. You should follow the tips for a balanced diet. On the other two days of the week, you reduce the food you eat to around a quarter of your normal calorie intake. For most people, this is equivalent to a quantity of around 500 kcal.

You do not have to fast for two consecutive days. With 5:2 intermittent fasting, you can arrange the days in the order you wish. Tip: do not schedule weekend days as intermittent fasting days. You should eat how you normally eat at weekends

How to ensure a balanced diet

The 16:8 method

Another variation is 16:8 fasting. This is where you limit your day’s mealtimes to within an eight-hour period. You then fast for 16 hours. During this fasting period, you do not eat any solid food or drinks containing calories. You are allowed to drink coffee, but without milk or cream. If you eat your dinner at 7 p.m., for example, you should plan to eat your next meal after 11 a.m. the following day. At weekends, you either follow your normal eating schedule or you continue with the 16:8 method. 

Dinner cancelling

Dinner cancelling also counts as a form of intermittent fasting. It involves not eating dinner on some days. This corresponds to a fasting period of around 14 hours. This method especially suits people new to fasting or those who find fasting for 16 hours difficult.alories for 16 hours. If you eat your dinner at 7 pm, you should plan to eat your next meal after 11 am. Normal food consumption can be resumed on the weekend or the 16:8 pattern can be continued.

Men vs women

Fasting can disrupt the balance of hormones. This has a bigger effect on women than it does on men. However, not everyone will have such a strong reaction. That’s why it is important to listen to your own body, and if required, to consult your gynaecologist.

How does intermittent fasting work?

Today, we can buy food quickly and cheaply almost any time of the day and night. There is temptation everywhere. However, if our body is constantly taking in food, it has no need to rely on reserves it has built up. The result is: our body converts excess calories into fat deposits. We put on weight as a result. But our bodies do not need constant food input.

The benefits of intermittent fasting are: by extending the periods between eating, our body is forced to fall back on its reserves. This should cause improvement in our metabolism. This is how intermittent fasting helps us to lose weight – but that’s not the only benefit. Not eating for longer periods also stimulates our cells’ self-cleaning function, a process known as autophagy. The more frequently this process occurs in our body, the healthier it is and it will live for longer.

Why intermittent fasting is healthy:

  • blood pressure, blood sugar levels and cholesterol counts improve.
  • We gradually lose belly fat and weight.
  • The body produces fewer inflammatory messengers. This can slow down the development of autoimmune diseases.
  • Intermittent fasting helps you sleep better.

Another benefit of intermittent fasting: you don’t have to go without. The usual recommendations for ensuring a balanced diet apply.

Do you have any questions about your diet or weight?

Our health consultation advisors are happy to help you. We can offer you information and tips on a balanced diet and controlling your weight.

What are the disadvantages of intermittent fasting?

There are currently no long-term studies that rule out the possibility of negative effects on people’s health. This includes, for example, whether, in the long term, the body can get the nutrients it needs during fasting. No definitive conclusions can be drawn on whether intermittent fasting is a better method for regulating our weight than other methods. Equally unclear is whether intermittent fasting could potentially contribute to people developing eating disorders.

You should always be careful. Seek advice and supervision from a specialist in the field if you have health problems or a BMI above 30. And anyone with a healthy BMI of between 20 and 25 should not overdo losing weight – your weight is absolutely okay.

Who should avoid intermittent fasting?

You should avoid intermittent fasting if you are pregnant. The same goes for when breastfeeding. This is because in these cases, it is especially important to eat a balanced diet that contains all micronutrients. It forms the basis for the healthy development of the child.

Children and adolescents should not fast. They need a good supply of nutrients in order to grow and so that their bodies develop without problems.

If you suffer from a chronic illness such as diabetes, depression or cancer, or take regular medication or are trying to have a baby, you must discuss any plans on fasting with your doctor beforehand.

Read more

Lose weight without feeling hungry – here’s how
These healthy yet filling options can help you lose weight.
February 22, 2023 2 minutes

Mediterranean diet: the benefits of the Mediterranean diet
Healthy and tasty: why you should switch to the Mediterranean diet.
February 9, 2023 3 minutes


Find out more about current health issues every month and get all the information you need about our attractive offers from all Helsana Group companies * delivered by e-mail to read whenever it suits you. Our newsletter is free of charge and you can sign up here:


Thank you for registering.
You have just received an email with a confirmation link. Please click on this to complete your registration.

Unfortunately an error has occurred.

We did not receive your information. Please try again later.

* The Helsana Group comprises Helsana Insurance Company Ltd, Helsana Supplementary Insurances Ltd and Helsana Accidents Ltd.