What is intermittent fasting and how does it work?
Intermittent fasting is now on everyone’s lips and is regarded as the secret to quickly and sustainably shedding excess pounds. But what do 16:8 and 5:2 mean? We answer these and many other questions about intermittent fasting for you in our informative guide.
What is intermittent fasting?
Intermittent fasting (also: intermittent fasting, IF) is a form of fasting. Many metabolic health benefits are attributed to it. Those who fast abstain from food for hours or even days and give their digestive system a well-deserved break. Intermittent fasting is also known as a form of dieting.
Which intermittent fasting methods are there?
If you decide on intermittent fasting, you can choose between different methods. Here you will encounter 5:2 and 16:8. These are the most common variants for targeted fasting.
The 5:2 intermittent fasting method
In this variant the fasting refers to individual days. On five days a week you eat normally; on the remaining two days you fast. Alternatively, you can eat normally for six days and abstain from food on the seventh day.
During the week you can eat normally. You do not have to count calories. On the two chosen fasting days you do not completely abstain from food; the energy intake is reduced. For men, intake is about 600 to 850 calories; for women, 500 to 800 calories are ideal.
Important: On fasting days you should drink plenty of calorie-free beverages. You should also avoid rapidly digestible carbohydrates such as pasta, potatoes, sugar and wheat bread. This teaches your body to tap its reserves.
The 16:8 intermittent fasting method
While the 5:2 method refers to whole days, the 16:8 method is about hours. During eight hours you may eat anything, then you fast for 16 hours. This also works with 15:9 and 17:7. It depends on what you feel comfortable with and on your daily rhythm.
Worth noting: If you have your last meal around 5 p.m., you may eat again at 9 a.m. In addition, the body has less digestion to deal with at night and can REST significantly better.
Alternate-day fasting (Alternate-Day-Fasting)
The third form of fasting is alternate-day fasting. In this variant you eat normally on one day and on the following day consume only about 25 percent of the energy you usually require. It alternates between regular days and fasting days. It is important to maintain a balanced diet so that the body receives all necessary macro- and micronutrients.
Attention: This fasting method may sound attractive, but it is a real challenge for the body. If you want to try this form, you should consult your primary care physician beforehand.
The benefits of intermittent fasting
- supports healthy weight loss
- can be carried out in a wide variety of forms
- prevents the breakdown of protein in muscles
- promotes fat and glucose metabolism
- the body can better combat inflammation
- the yo-yo effect is avoided
Even in prehistoric times humans were adapted to periods of fasting. When food was abundant it was consumed without restraint. When food shortages occurred the stomach remained empty for longer periods. Humans survive periods of hunger without difficulty. Energy stores are established in organs and tissues. These are mobilized when needed and supply the body with energy.
Worth knowing: Energy expenditure minimizes after a few days. At this point the body begins to break down protein and consequently muscle.
To prevent this, intermittent fasting is used. Unlike prolonged periods of starvation and crash diets, metabolism is not downregulated. Muscle mass is preserved because the body does not tap into protein stores. As a result, the notorious yo-yo effect does not occur.
But intermittent fasting is famous not only for weight reduction but also for restorative effects. Biochemical changes occur in the body. Glucose and lipid metabolism improve. In addition, substances are released that can reduce and dampen inflammation.
How long should the intervals between meals be?
There should be at least four to five hours of rest between meals. If you consume a cookie, milk, fruit juice or similar, your body converts it into sugar. This raises your blood glucose and triggers insulin release. Ultimately fat breakdown stops. Afterwards the short insulin high can cause cravings because the body is briefly slightly hypoglycemic.
Intermittent fasting with medical conditions
Most people benefit from the health advantages of intermittent fasting. However, if pre-existing conditions are known, the topic should be approached with caution. With low blood pressure, metabolic disorders, cancer, chronic illnesses, or advanced age, you should consult your primary care physician in advance.
Important: Intermittent fasting is not suitable during pregnancy, while breastfeeding, or in cases of underweight, bulimia, and anorexia. Migraine sufferers should also refrain from intermittent fasting.
Exercise and Intermittent Fasting
If you are new to the topic and are starting intermittent fasting, avoid excessive physical strain. The body needs time to adapt to the new nutrient schedule. Until it has learned to tap into its reserves and provide sufficient energy, strenuous exercise should be avoided. Walks and light workouts can, however, remain part of daily life.
The Right Portion Sizes
People often tend to increase their portion sizes. It is important, however, to continue eating as before. If, for example, you fast 16:8, you should not overload your body during the eight hours. Foods that are filling and keep you satiated are the best option. These include:
- Legumes
- Dairy products
- Eggs
- Nuts
- Mushrooms
- Fish
- Meat
Good to know: Snacking between meals is discouraged. This allows the metabolism to work undisturbed and for the food to be digested.
Conclusion – Intermittent Fasting
Which fasting method is right for you should ideally be decided on an individual basis. In some cases it is advisable to consult your primary care physician in advance. Intermittent fasting brings many health benefits and helps with weight loss without the yo-yo effect. No wonder intermittent fasting is so popular.
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