Intermittent fasting helps you lose weight in a healthy way. With longer breaks between meals, you can easily integrate the principle into everyday life – without counting calories. We show you the different methods.
For many, long-term fasting is a real ordeal. Intermittent fasting requires only minimal adjustment and after at least ten days it starts to become a habit. The advantage: the different methods of intermittent fasting help you to maintain your weight or lose weight in a healthy way.
So that you know exactly what you are allowed to eat and drink, we have also put together a sample daily schedule for the 16:8 method.
What does intermittent fasting mean?
Intermittent fasting is also known as intermittent fasting (lat. intermittere = interrupt, suspend). Part-time fasting is also a term that is used interchangeably. Nevertheless, this is not a fasting cure in the classic sense.
Instead, phases of normal nutrition alternate with periods of complete abstinence at shorter intervals. This is how the eponymous intervals are created.
What are the benefits of intermittent fasting?
Intermittent fasting is no longer just a trend but is considered a healthy all-purpose weapon in terms of fat burning, intestinal health, and cell regeneration.
Advantages that make part-time fasting attractive for a healthy change in diet:
- Lose weight without cravings or feeling weak
- no calorie counting or avoiding carbohydrates or fats
- positive regulation of blood sugar levels and thus preventative against diabetes
- preventively applicable for heart disease and cancer
- conscious consumption of food
- Healthy sleep
- adjusting hormone balance between cortisol, leptin, and ghrelin
Intermittent fasting: how it works
If you want to try intermittent fasting, there are three basic rules for you:
- First, you should find out which of the methods works best for you. Your choice will depend on how long you can go well without food. The various methods differ in the frequency and duration of food restriction.
- During the fasting phase, only water or unsweetened drinks such as coffee or tea are allowed. During this time, the body gets everything it needs from its reserves.
- The rest of the time you can eat normally. Follow the usual recommendations for a healthy diet. These include avoiding refined sugar and fast food as far as possible and not eating too much or too late. Otherwise, there are no further requirements. Depending on individual goals and preferences, different forms of intermittent fasting are possible, which differ in their ratio of fasting time to mealtime.
Intermittent fasting: what methods are there?
The methods of intermittent fasting are based on the individual needs and preferences of the user. Intermittent fasting is therefore also possible with low food intake during the abstinence phase. But methods with long-lasting and absolute abstinence are also available.
Below we explain the different methods in more detail.
Intermittent fasting using the 16:8 method
The currently most popular and most efficient form of intermittent fasting is the 16:8 method. 16:8 intermittent fasting is based on time-restricted feeding. This means that the time span of food intake is limited at the daily interval.
In each 24-hour interval, you are allowed to eat within an 8-hour segment and not during the remaining 16 hours. That means you need to time your meals accordingly. In principle, you can access the foods you feel like eating during your active eating phase. However, three healthy and balanced meals within the 8-hour interval are recommended.
The short intervals between meals will make it easy for you to do without unhealthy snacks in between. In this way, you automatically build in smaller fasting intervals within eight hours. By the way: The increased form of 16:8 is the 20:4 variant – also known as the warrior diet. This extreme variant is not suitable for beginners and is only suitable for a short time.
- Pros: With 16:8 you can choose the period of fasting that suits you. If dinner is celebrated in your family, you postpone breakfast. This makes the method suitable for everyday use.
- Caution: pregnant and breastfeeding women, children and people with eating disorders should not fast according to the 16:8 method.
- Especially suitable for: Anyone who prefers to look at the clock than count calories. Good for beginners as they don’t need to fast for whole days or longer. Ideal for professionals.
- Weight loss factor: 1 to 2 kilograms per week are possible.
Intermittent fasting using the 5:2 method
The British nutrition expert Michelle Harvie developed the 5:2 concept with colleague Tony Howell at the University Hospital South Manchester.
Eat whatever you feel like eating for five days – and fast for two days. In this concept, a small amount of food is allowed during the fasting period. Women are allowed to eat up to 500 kcal and men up to 600 kcal, for example in the form of vegetables, fruit, or soups.
As a result, you do not have to do without solid food completely on the fasting days. The choice of fasting days is also arbitrary, they should just not be consecutive. So you can relax, for example, take part in a birthday party or occasionally go out to eat. It is important to drink enough calorie-free beverages such as water or unsweetened tea.
- Advantages: The 5:2 diet is suitable for everyday use and is flexible. Due to the restricted food intake, the fasting days and thus the method itself can be endured well. After the diet phase, you switch to just one fasting day, which allows you to maintain the weight you have achieved.
- Caution: The 5:2 method is not suitable for children, pregnant women, competitive athletes, people with an eating disorder, or who are underweight. If you have diabetes or other chronic diseases, you should discuss the intermittent fasting method with your doctor.
- Particularly suitable for: People who do not count calories or want to do without carbohydrates or fats, but can easily reduce the amount of food they eat. This method regulates blood levels.
- Weight loss factor: 500 to 800 grams of weight loss per fasting day are possible.
Intermittent fasting using the 6:1 method
California-based journalist and author Jane Kennedy is the inventor of the One-Day Diet. Her focus is on health, naturopathy, and wellness.
This method involves fasting just one day a week. The focus on this day is on plenty of fluids (at least three liters) and fat burner drinks. For example, you can add 1 teaspoon of apple cider vinegar and 1 teaspoon of honey to a glass of water. Or stir the juice of half a lemon into a glass of water. The drinks curb hunger and stimulate the metabolism.
Diluted juices, whey, and fat-free broth are also allowed. Coffee, alcohol, and high-calorie drinks must be avoided. On the remaining six days of the week you eat as usual – of course as varied and calorie-conscious as possible. It is advisable not to eat anything heavy the evening before the fasting day. This allows the body to get in the mood for the diet day.
- Pros: You don’t have to fear a yo-yo effect since you’re fasting one day a week. You can also put the fasting day on the weekend to avoid stress on working days. The method is gentle and usually well tolerated. This allows it to continue indefinitely.
- Caution: Fasting is not recommended during pregnancy and after surgery.
- Best for: Anyone who wants to control their weight but doesn’t want to put in too much effort.
- Weight loss factor: You can lose up to 800 grams on a fasting day, but overall the method is more suitable for maintaining weight and relieving the body.
Intermittent fasting using the 10:2 method
The method is also known as alternating fasting, i.e. eating and fasting alternately. The number 10 is spoken separately. So “one” and “zero”. In this case, the 2 means in two days. In summary, this means: eating one day (1) and fasting one day (0) within 2 days.
This variant was invented by the Austrian cabaret artist and psychologist Bernhard Ludwig according to the motto: “Become and stay slim with pleasure”. He has lost over 20 kilos with this method. The book on his recipe for success: Tomorrow I can eat whatever I want.
Food intake on the dinner day normally takes place over a period of twelve hours. This is then followed by 36 hours of not eating. In this way, the body is only deprived of nutrients for a short time. Anything you like is allowed for dinner.
- Pros: Alternating fasting is the most effective and calorie-saving form.
- Caution: You should be fairly fit for frequent fasting. There is no yo-yo effect, but it does put more strain on the body than the gentler fasting methods.
- Particularly suitable for: People with fasting experience who want to lose a lot of weight over a longer period of time.
- Weight loss factor: 2 to 2.5 kilograms per week should tumble at least at the beginning.
Eat during the day, fast in the evening – Dinner Cancelling
Dinner canceling is a well-known form of dietary change and can be considered a precursor to intermittent fasting. Current studies show that it makes particularly good sense not to eat anything after 4 p.m. This is related to the circadian rhythm – day and night determine the metabolism.
In test subjects, the same food caused a lower rise in blood sugar levels in the morning than in the evening. As the name suggests, dinner canceling is about skipping dinner.
You can increase the effect if there are as many hours as possible between the last meal of the day and the next one – i.e. breakfast. During this time, you are allowed to have non-caloric beverages such as water and unsweetened tea. However, avoid coffee in the evening, as it can negatively affect the sleep cycle.
At breakfast the next morning, make sure that you don’t add the calories you saved from the evening.
- Advantages: Canceling dinner once or twice a week is easy. Always remember that fat burning works better overnight than during the day. This ensures good results with only small cuts in the habits.
- Positive side effects: You gain time to do something for yourself, and your sleep becomes more peaceful.
- Caution: Not so ideal for those who eat together as a family in the evening. A glass of hot water or herbal tea helps with nighttime cravings.
- Particularly suitable for: Fasting newcomers, cooking haters, and singles.
- Weight loss factor: Up to 500 grams less are possible.
How long can I do intermittent fasting?
In contrast to therapeutic fasting or detoxing, periodic fasting is not only used for a certain period of time, but over a longer period of time. If you get along well with intermittent fasting, you can practice it for the rest of your life. After a short time, you will find your own rhythm, which adapts to the respective method.
You will also feel the positive effects if, for example, you fast intermittently three out of seven days a week. For starters, you can start with a few days a week.
- Don’t worry: the body is prepared to not eat anything for a long time. The more often you do it, the better it is for your health and especially for your weight loss success.
How healthy is intermittent fasting?
Countless testimonials speak for themselves: intermittent fasting works. But what does the scientific study situation look like? Is it really as healthy as people claim it is? You can find out more about the different studies here.
Prevention for diabetes, cancer, and heart disease
In fact, various studies have shown that eating breaks lead to longer lifespans and prevent or alleviates many diseases.
For example, experiments were carried out with mice that were specifically exposed to breaks in eating. Scientists observed an improvement in blood values and a reduced likelihood of diabetes, cancer, or heart disease due to the slight calorie deficit.
In another study, intermittent fasting even had life-prolonging effects. However, it has not yet been scientifically possible to show whether the results can be transferred to humans.
Studies show: Intermittent fasting helps with weight loss
And also when it comes to losing weight, previous analyzes allow a positive conclusion. An analysis from 2015 concludes that intermittent fasting is a valid option for energy restriction in relation to weight loss, fat mass, and blood sugar regulation.
Another study also showed that intermittent fasting is superior to a diet with continuous calorie and carbohydrate restriction. Subjects showed greater body fat reduction and improved insulin sensitivity.
Choosing the right method is crucial
Opponents of the popular 16:8 method, on the other hand, argue that 16 hours are far too short to create a ketogenic metabolic situation in the body, as with therapeutic fasting – i.e. switch to fat burning instead of storing glucose.
For the organism, especially for the heart, the concentrated food intake alternating with pseudo-fasting may even be extremely stressful. The hormone balance can also be messed up if the fasting window is too large.
Nutritional evaluation by the DGE
The German Society for Nutrition (DGE) points out that there have only been a few human studies examining the effects of intermittent fasting. The many different forms of fasting and the different study participants (e.g. normal weight or overweight) make the evaluation even more difficult. To date, there are no studies on the long-term effects of fasting.
Nevertheless, the DGE emphasizes that the data to date indicate a positive effect of intermittent fasting on health and weight loss.
Risks and side effects of intermittent fasting
There are no specific risks associated with intermittent fasting. Side effects of intermittent fasting can include fatigue or headaches. If you notice these symptoms in yourself, a visit to your family doctor is advisable. There you will clarify together whether and how you should practice one of the fasting methods.
Keep in mind that while you are fasting you are consuming fewer calories, but also fewer nutrients than usual. A balanced diet during the eating phase is all the more important. This is how you cover your need for nutrients, minerals, and trace elements.
Who is intermittent fasting suitable for?
For many people, intermittent fasting is an interesting way to lose body fat without banning certain foods or maintaining your current body weight despite some munchies. Nevertheless, it is very individual how well a person can sustain a limited food intake.
Although intermittent fasting has a positive effect on most people, the fasting method is not suitable for everyone. You should rather ask your doctor before you start if, for example, you have low blood pressure, suffer from metabolic diseases, or have chronic diseases or cancer.
Intermittent fasting is also not suitable for children and adolescents, during pregnancy and breastfeeding, for eating disorders such as anorexia or bulimia, and for those who are underweight.
What can I eat during intermittent fasting?
With intermittent fasting, there are no or hardly any specifications as to what is eaten or drunk. That means: Salad and curry are okay – but also doner kebab and cola?
The DGE criticizes that many intermittent fasting concepts give no or only very vague recommendations as to what exactly should be eaten during intermittent fasting. Often there is no change in diet at all when beginners start intermittent fasting. So if you continue to eat unhealthily, you may lose weight – but not in a healthy way.
Optimal nutrition for intermittent fasting
In order to get the maximum benefits of intermittent fasting, you cannot avoid a balanced diet. That means Two to three large meals a day that provides you with filling proteins, healthy fats, energy-giving carbohydrates, and vital substances.
A porridge, muesli with fruit or an omelet with vegetables and avocado is suitable for breakfast.
Lunch and dinner should consist largely of vegetables and plant-based protein sources, such as legumes, soy, or pseudocereals.
Sweets, red meat, trans fats, and alcohol should be avoided as much as possible.
Green vegetables such as broccoli, spinach, or pak choi contain only a few calories, but boast a large number of vitamins and minerals as well as secondary plant substances.
Fruit should also not be missing, for example, strawberries, blueberries, bananas, or apples.
Good fats from avocados, salmon, olives or seeds, and nuts give you the energy you need for the day.
It is advisable to rely on purely plant-based food for the last meal before and the first food intake after the fasting phase. This is base-forming and supports the body in breaking down unwanted substances.
Drinks during the fasting phase
No matter which fasting method you have chosen for yourself: It is important that you drink enough – especially during the phases of not eating. This is how you support fat burning and cell regeneration.
Still, water or unsweetened herbal or fruit tea is best. Milk, soft drinks, sweetened iced tea or other high-energy drinks are taboo.
The coffee is perfectly okay – but only black. Unfortunately, latte macchiato and cappuccino do not count as they contain milk.
Is alcohol allowed with intermittent fasting?
Alcohol is allowed during intermittent fasting, but only during the eating window and in moderation. If you drink alcohol while fasting, you break the fast.
Meal plan for intermittent fasting
We have put together a sample day for you for the popular 16:8 method of intermittent fasting.
Tip: If you want to start intermittent fasting, it is best to start at the weekend. With a late brunch, early dinner, and enough sleep in between, it’s relatively easy to get into a 16-hour fast
According to expert Dr. medical For Petra Bracht, the ideal eating window is between 12 noon and 8 p.m. so that the method can also be implemented on working days.
Your everyday life during the 16:8 intermittent fasting method
- 8:00 a.m., at home: two large glasses of still water
- 9:00 a.m., in the office: a cup of black coffee or a cup of unsweetened herbal tea
until 11:00 a.m.: two glasses of water or tea
- 11:00 a.m.: Breakfast – overnight oats in a glass, muesli in a Tupperware can or a filling green smoothie will give you energy again after the fasting phase.
- 1:30 pm: Lunch – Light dishes such as soups or salads are ideal. The more colorful the better. Salad bowls, quinoa, or chickpea salads are good sources of nutrients. Make sure you also include protein and fiber foods in the salad, such as chicken, tofu, beans, or lentils. They fill you up for a long time.
- 4:00 p.m.: Attention, now the afternoon low is lurking. Vegetable sticks with hummus, a handful of nuts, two pieces of dark chocolate, or an apple will help you stay focused.
- 6:30 p.m.: Dinner – Now you can enjoy it again before the fasting phase begins. Cook a delicious vegetable curry with rice, a fiery lentil dhal with spinach, or a potato salad with zucchini, green asparagus, tofu, and fresh herbs. Make sure to use high-quality and healthy fats, e.g. B. olive or linseed oil.
- In between: drink plenty of water. A cup of fruit tea helps against sweet cravings in the evening.