Approximately 40% of adults in the world are overweight or obese (BMI> 25 kg / m2). This is not only associated with an increased risk of health problems such as cardiovascular disease, diabetes, mellitus type II, and certain types of cancer, but also leads to stigmatization, discrimination, and high healthcare costs. Many people are therefore looking for an effective and above all easy way to lose weight. Intermittent fasting can then be the solution.
What is Intermittent Fasting?
In intermittent fasting, you alternate a period of fasting with a period in which you normally eat, without restrictions. In principle, many people do that by not eating anything between the evening meal and breakfast. However, intermittent fasting also refers to daytime fasting. There are three different ways of intermittent fasting, within which different variants are possible:
A certain period of one-day fasting- A fasting period of a number of consecutive hours in a day (18-20 hours fasting and 6-8 hours of normal eating). Skipping breakfast is an example of this. Another well-known example is Ramadan, where from sunset to dawn (prior to sunrise) is fastened.
Incidentally, it is not the case that on a full day of fasting nothing at all can be eaten, but usually, this is less than 25% of the energy requirement. Drinking is unlimited as long as there are no calories (water, tea, coffee).
Alleged Mechanisms Behind Intermittent Fasting
The regular approach to losing weight is a constant, moderate energy restriction. By getting fewer calories every day than you consume, you lose weight. So, you also gain weight when you consume more calories every day than you consume. This is known as the energy balance and it leads to weight regulation. A disadvantage of energy restriction is that it is a threatening situation for the body. The body, therefore, operates various mechanisms to end that threatening situation. Examples of such mechanisms are-
With intermittent fasting, the body would not experience a threatening situation and would therefore not initiate mechanisms that prevent weight loss.
Regardless of the way of losing weight, it can’t be avoided that part of the weight loss consists of muscle mass (about 25%). This can be limited by eating enough protein and doing weight training. Intermittent fasting can also limit the loss of muscle mass. Because little carbohydrates are eaten during fasting, the body (the liver) converts fatty acids into so-called ketone bodies (Acetylacetic acid, ?-Hydroxybutanoic acid) that are used as fuel mainly by the muscles and brains. These ketone bodies would save the muscle mass during an energy shortage.
What do studies show?
There are a number of overview studies in which regular energy reduction is compared with different forms of intermittent fasting. This shows that intermittent fasting is effective for weight loss, reduction of fat mass, and reduction of the waist circumference, but it is not more effective than regular energy limitation. Similar effects are also generally found in muscle mass, although one small study of intermittent fasting showed a greater loss of muscle mass. However, there are indications that intermittent fasting reduces appetite in the long run. Possibly this is caused by the production of ketone bodies during fasting.
For whom is intermittent fasting suitable?
Losing weight in the short term is often not that difficult. With every diet, most of them do, even with periodic fasting. The problem is the next step: weight maintenance. How do you ensure that the lost kilos remain? The motivation becomes less and the temptations only seem to increase. It is therefore important to choose a diet that you can sustain. For this, you will have to make a personal assessment of the advantages and disadvantages. The advantages and disadvantages of intermittent fasting do not weigh equally for everyone.
Benefits - The rules are clear
It is therefore not a method that is suitable for everyone. Ultimately, it is all about the energy balance and intermittent fasting can be a way to create a negative energy balance that causes weight loss.
For whom is intermittent fasting not / less suitable?
Intermittent fasting is less suitable for a number of people, regardless of whether they could sustain it. For them it is wise to first consult with the General Practitioner:
Intermittent fasting is one of the ways you can lose weight and fat mass. This is because you can create a negative energy balance with it. However, the effectiveness is comparable to regular energy reduction. Whether it suits you depends mainly on your personal preferences.