Weight loss without starving and be vital and efficient – that’s what many weight loss enthusiasts hope for from intermittent fasting. The fan community of so-called intermittent fasting is growing. Differently than with the traditional chamfered one does not do without food for days or even over several weeks. The chamfering phases are manageable and alternate with phases of the normal nutrition – so this rhythm can be integrated very well into the everyday life. In addition to weight loss, periodic fasting is also said to improve sugar and fat metabolism. How interval fasting works, what it brings and how healthy this form of diet is, you will learn below.
What is interval fasting?
Characteristic of interval fasting, which is also called intermittent fasting, is the alternation of phases of eating and phases in which nothing is eaten – so you fast in intervals. There are different forms of intermittent fasting: fasting can be done by the hour, but it can also be done for a complete day. Intermittent fasting does not require complicated instructions or a special diet plan – what matters are the intervals of eating and fasting.
Intermittent fasting according to plan: what are the methods?
Depending on how long the intervals last in each case, a distinction is made between different methods of interval fasting. The most popular forms are:
- The 16:8 method
- The 5:2 method
- The 1:1 method
- The 12:12 method
In addition, different spellings are also common, for example, “16/8 method”, “16-8 method” or “5 to 2 method”. All designations describe the ratio of the duration of eating to fasting intervals.
What does 16:8 interval fasting mean?
The 16:8 interval fasting is the most popular form of interval fasting. Here, you limit the time you are allowed to eat to eight hours. The remaining 16 hours of the day is fasted – one speaks in this connection also of the 8-hour diet. A daily plan with this method could look thus in such a way that one takes daily only between 11 o’clock and 19 o’clock food to itself. In the time to 11 o’clock on the following morning only calorie-free beverages are permitted. Alternatively one can put the meal phase also from 8 o’clock to 16 o’clock and do without the dinner. One of the special advantages of interval fasting: Such a plan can be flexibly adapted. If, for example, a dinner in sociable round is imminent, one can extend the fasting phase so far that the 8-hour time window for the meal is pushed back in time.
Intermittent fasting in a 5:2 ratio.
The 5:2 variation involves eating normally, without meal breaks or restrictions, five days a week. On the two remaining days, the calorie intake is limited to approximately 500 kcal (kilocalories) for women and 600 kcal for men. Ideally, you should avoid easily digestible carbohydrates such as those found in pasta, wheat flour or sugar on these days and reach for low-sugar fruits, vegetables and lean sources of protein. Ideally, choose non-consecutive days for the two fasting days, when you also have little stress.
1:1 method and 12:12 method – fasting and eating in sync.
“Eat Stop Eat” or alternate fasting describes the 1:1 method of interval fasting. This form involves alternating between doing without food one day and eating normally the next. In the 12:12 method, the intervals are only 12 hours each – a relatively short form of “part-time fasting”. So one can put for example the time window for eating between 7 o’clock and 19 o’clock – for many anyway a normal daily plan. However, because of the comparatively short break from eating, this is not a common variation of interval fasting.
Interval fasting for beginners
For beginners, the 16:8 form of interval fasting is particularly suitable, because the night’s rest counts as a meal break. If you will: lose weight while you sleep, which incidentally often contributes to an improvement in sleep quality. Incidentally, the 16:8 interval fasting has gained great popularity in particular through the television physician Dr. Eckart von Hirschhausen, who was able to achieve considerable success and lose ten kilograms himself with it – this form of fasting is therefore occasionally also referred to as the Hirschhausen diet.
What can you eat during interval fasting?
Intermittent fasting relies on a healthy diet, but without giving specific guidelines or imposing restrictions.Thus, during the eating phases, one should neither eat immoderately nor count calories meticulously. As is so often the case with intermittent fasting, a healthy and balanced mix is the key to success. During the fasting phases should be drunk exclusively, and as far as possible calorie-free – the most suitable are:
- Water (if necessary with a dash of apple cider vinegar or a slice of lemon).
- Thin vegetable broth
- Highly diluted juice spritzers
- Unsweetened tea
Coffee is also allowed, but without sugar and sweeteners. Those who drink their coffee with milk can continue to do so. Milk has some calories – but a small sip will not ruin the success of interval fasting. During longer periods of fasting, a home-cooked vegetable or chicken broth can help provide the body with nutrients and alleviate hunger pangs.
Is alcohol allowed during interval fasting?
Just as you are allowed to eat normally during meal periods, alcohol is also allowed during Intermittent Fasting. However, this too, of course, only in moderation. During the fasting intervals, however, alcohol is taboo.
Lose weight with interval fasting?
Scientific studies on mice have shown that eating according to the principle of interval fasting can improve weight problems. It is not necessary to reduce the amount of calories to induce weight loss. A pilot study with human subjects also seems to prove this. In addition, another study was able to show that less fat-free mass is lost during interval fasting than during a diet with calorie reduction.
How does interval fasting work?
The principle of action of interval fasting, unlike other diets, is not based on reducing calories, but aims to make the body adjust its metabolism by taking long breaks from eating. The theory behind it: If a meal break lasts more than 14 hours, the body switches from burning carbohydrates to burning fat – and uses the fats stored in the body to do so. In contrast to a crash diet, in which the metabolism switches to “economy mode”, interval fasting should also not have a yo-yo effect. For this reason, interval fasting is popular for weight loss.
Further effect on health
But also other health-promoting aspects could be observed in the above-mentioned mouse study. Thus the blood values of the mice were improved and thus the danger of the illnesses of heart and cycle reduced. Also an anti-inflammatory effect as well as an improvement of the LDL cholesterol values could be shown already several times. If food intake is spread throughout the day, the body repeatedly releases insulin. However, the insulin prevents fat burning for several hours. Over time, the body’s cells develop immunity to the insulin and thus a precursor to diabetes. Intermittent fasting may be able to counteract such a disorder. This is indicated by studies in which an improvement in insulin sensitivity has already been observed. Another positive consequence of intermittent fasting is an increased release of the growth hormone somatropin. This hormone has an influence on fat metabolism and protein synthesis. This results in increased muscle growth.
Cell cleansing through interval fasting
The effect of cell recycling – so-called autophagy – is also frequently mentioned in connection with interval fasting. During the fasting phase, the individual cell obtains its energy from components that are not essential for survival, for example, from old and defective cell parts – in this way, the cell cleans itself. However, overeating disrupts this process. By fasting, on the other hand, the body is no longer occupied with digestion and can turn its attention to cell cleansing. Animal studies even suggest that this effect could have a life-prolonging effect.
7 Tips: How to succeed with interval fasting
For successful interval fasting, take the following tips to heart:
- Start slowly: To get started, it may be advisable to begin with a fasting interval of 12 hours and then slowly extend the fasting period to 16 hours.
- Do not expect too much: Avoid physical stress during the fasting intervals, especially in the beginning.
- Eat a balanced and healthy diet, with plenty of vegetables and protein and not too many carbohydrates.
- Refrain from snacks between meals and excessive gluttony – just eat normal portions.
- Make sure to drink plenty of fluids throughout the day. The best way to start the day in the morning is with a glass of water.
- Some exercise on an empty stomach can help boost digestion. Even 10 minutes of walking or jumping rope can be enough.
- Against hunger attacks help coffee or drinks with flavor, for example, a glass of water with a slice of lemon.
How long should interval fasting last?
How much and how fast you can lose weight with interval fasting is quite different and, of course, depends on how you eat during the eating periods. There is no time limit for the fasting method. If the focus is on losing weight, you can slowly reduce interval fasting and gradually end it when you have reached your weight goal. However, it is also possible to use intermittent fasting as a long-term form of nutrition. In this case, it is sufficient to fast three days a week according to the 16:8 method, for example.
Side effects and disadvantages of interval fasting
Dizziness, headaches and freezing can occur as side effects, especially at the beginning of interval fasting. However, these minor side effects usually subside after an initial period of acclimation. A possible cause for an occurring feeling of dizziness can be a lack of salt. Adding a pinch of salt to a glass of water can help. You should also make sure that you drink enough. Hot tea, a warm foot bath and an extra layer of clothing will help against the chill.
Who is interval fasting not suitable for?
In principle, any healthy person can try interval fasting. However, for children, teenagers, as well as breastfeeding women and pregnant women, intermittent fasting – just like other diets – is considered unsuitable, as the risk of nutrient deficiency is too high. The same applies to older people and people with severe underweight or eating disorders. If you are taking medication, you should check with your doctor before you start fasting to see if interval fasting is suitable for you. Caution is especially advised for people with diabetes, as fasting can lower blood sugar levels, which can be dangerous when combined with blood sugar-lowering medications. If you have pre-existing conditions such as cancer, metabolic diseases, low blood pressure or chronic diseases, it is also advisable to talk to a doctor first.
Criticism of interval fasting
Even though initial scientific studies attribute positive effects to interval fasting, there is also criticism. The DGE (German Society for Nutrition) does not attribute any lasting benefit to interval fasting: “The DGE does not consider this method to be useful for regulating weight in the long term. A conversion to a health-promoting nutrition does not take place hereby.” Also researchers of the German cancer research center in Heidelberg certify the 5:2-Methode no better successes regarding removing than a reduction of the daily calorie supply. The number of human-medical studies to the effectiveness of the Intervallfastens as well as to its effects on the health is so far still small, long-term studies are missing completely. Often the results contradict each other or the scientists draw different conclusions from their observations. In addition, the different studies work with different types of interval fasting, which makes the results hardly comparable. Therefore, it is too early to make a conclusive assessment of the benefits or possible side effects of interval fasting.
Conclusion: interval fasting may be worthwhile
The effects observed in studies suggest that not only the what, but also the when can be crucial for a healthy and vital body. Even if the effect of the fasting method has not yet been sufficiently investigated, many scientists see in interval fasting the potential to counteract diseases – negative effects cannot be derived from the studies conducted so far. However each part-time fasting must be conscious that in the meal phases not everything and certainly not in excessive quantities should be consumed. The amount eaten and also the nutrient content of the food must always be kept in mind – a healthy food selection is therefore strongly advised.It is not in the sense of interval fasting to eat more than actually necessary in order to better survive the following food break. With a balanced diet, intermittent fasting could help to increase one’s well-being and additionally lose annoying pounds. Intermittent fasting is therefore not just a diet, but a nutritional approach to maintain weight and feel good. In combination with healthy recipes and exercise to balance everyday life, intermittent fasting can be a good basis for long-term (weight loss) success.
