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Intermittent fasting: how healthy weight loss works

With enjoyment
No deprivation
No yo-yo effect

Intermittent fasting at a glance

What is intermittent fasting?

Intermittent fasting is definitely a trend! What do the experts say: is this way of eating really better than a diet? Can you really get health-supporting effects from it without feeling restricted or having to give things up? We take a closer look at this method.

Intermittent fasting is a way of eating that alternates periods of eating with periods of fasting. The immediate aim is to put your body into a state during fasting where it draws on its stored energy reserves. Intermittent fasting is used for weight loss, and for other wellbeing benefits such as performance and concentration.

This method isn't about cutting out certain foods. The only rule is about eating at certain times. That means no complicated diet plans. This makes the concept fundamentally different from various crash diets, which we don't recommend. There are different approaches, such as the best-known 16:8 method (also called the 16:8 diet), which differ in the length of the fasting and eating windows. The 5:2 method and the Warrior Diet have also become well known.

What are the benefits of intermittent fasting?

What are the benefits of intermittent fasting?
Weight loss & improved metabolism

Weight loss & improved metabolism

The pounds drop off, without starving! By shortening your eating window, you automatically take in fewer calories and still feel full. For example, the 16/8 diet or the 5:2 method favours a negative energy balance and therefore weight loss. On top of that, there are scientific indications that it can have a positive effect on your metabolism by increasing insulin sensitivity and reducing inflammation, which can be relevant for metabolic health.

Heart health and blood sugar control

Heart health and blood sugar control

Some forms of intermittent fasting have been linked to improved heart health, such as lowering risk factors like high blood pressure and cholesterol. It can also help to regulate blood sugar levels and keep them as constant as possible.

Cellular recycling

Cellular recycling

During fasting periods, cellular repair processes (so-called autophagy) take place to a greater extent. In this process, aged, no longer needed or damaged cells are broken down or rebuilt.

Is intermittent fasting really as good as its reputation?

Scientific studies, plenty of individual experiences and the physical and mental benefits all play a big part in why intermittent fasting is so popular. This way of eating is a variation on traditional fasting (Heilfasten). Here are a few reasons why you might want to try this method too:

There is a growing number of scientific studies by experts suggesting that intermittent fasting may have various wellbeing benefits. These studies suggest that the methods may support your metabolism, improve your insulin sensitivity, help keep inflammation in check and even support certain heart health markers.

With intermittent fasting, the time in which you're allowed to eat is limited. Many people find it easier to eat less and so reduce weight this way. You don't get that typical diet feeling. The approach often leads to you snacking less and so taking in fewer calories overall.

Compared to pure diets, this way of eating is easier to put into practice. In the fasting phase, you only focus on the timing of your meals (for example eight hours): when you're allowed to eat again and when you should stop. You don't have to follow complicated food rules. During the eating phase, you automatically become more mindful of what you eat and how much.

The different methods of intermittent fasting allow a lot of flexibility, which many forms of dieting don't offer. Depending on your lifestyle and personal preferences, one method may suit you better or worse. Choose the approach that best fits your individual routine and preference.

Some people report that intermittent fasting helped them develop a better understanding of their hunger, eat less impulsively and more consciously. In contrast, many people report that dieting even made their cravings stronger.

Besides weight loss, experts point to signs that intermittent fasting may offer various wellbeing benefits, such as better blood sugar balance, support for certain heart health markers and potential support for cellular repair.

How does intermittent fasting work? The most popular methods at a glance

With intermittent fasting, for example the 5:2 diet, there are always periods of eating and periods of fasting that alternate regularly. The idea is to get your body to draw on stored energy reserves by allowing it longer periods without food. This lowers your weight. With intermittent fasting there are different methods that differ in the length of the fasting and eating phases. Here are some of the most common approaches:

5:2 method

5 days eating, 2 days fasting

On five days a week you eat normally, while on two non-consecutive days you reduce your calorie intake to around 500-600 calories. On the fasting days you eat small, low-calorie meals or snacks, and you get stronger autophagy than with the approaches where eating and fasting alternate within a single day.

16/8 method

16 hours fasting, 8 hours eating

This is one of the most popular methods! It's also known as the eight-hour diet. You fast for 16 hours and eat within an eight-hour window. One version is to eat between 12:00 noon and 8:00 pm, then fast for 16 hours until lunch the next day.

14/10 method

14 hours fasting, 10 hours eating

This one is similar to the 16/8 version, but with a shorter fasting window. You fast for 14 hours and eat within a 10-hour window.

Eat-Stop-Eat

Once or twice a week, you fast for 24 hours. For example, you start fasting after dinner at 7:00 pm and don't eat again until 7:00 pm the next day.

Alternate-day fasting

With this one, you fast or drastically cut your calorie intake every other day. On the days you eat, you can keep your normal diet.

Warrior Diet

During the day, you eat small amounts of raw fruit, vegetables and protein. In the evening, within a window of about 4 hours, you have one larger meal.

OMAD

One Meal A Day

With this one, you eat just one big meal a day and fast for the rest of the day.

Why short-term fasting is so effective

Promoting a calorie deficit

Intermittent fasting can lead to you taking in fewer calories over the day. The shorter eating windows limit the times in which you eat, which reduces the chance of overeating and can so lead to a natural calorie deficit, which in turn can contribute to weight loss.

Improved insulin sensitivity

Intermittent fasting may improve insulin sensitivity, which means your cells respond to insulin more efficiently and your blood sugar level stays steadier. This may contribute to healthy blood sugar balance over time.

Fat burning

Since your body isn't continuously supplied with food during fasting periods, it starts to draw on stored fat reserves as an energy source. This leads to increased fat burning, which in turn contributes to weight loss.

Hormonal changes

Intermittent fasting can cause changes in hormones such as insulin, glucagon, leptin and ghrelin. These hormones influence appetite, metabolism and energy balance.

Autophagy

During fasting, cellular cleaning processes such as autophagy (cell repair and removal of damaged cells) can be activated. This may support cell health in the long run.

Metabolic adaptation & inflammation control

Over time, your body adapts to fasting, which can lead to more efficient use of the available energy sources. Intermittent fasting may help keep inflammation in the body in check. Chronic inflammation is often associated with various health concerns.

Healthy weight loss with intermittent fasting

Before you start, find out about the different methods and their pros and cons. Understand how the mechanism works and how it can affect your body. Choose an approach that fits your daily life and preferences.

If you're brand new to it, start slowly. You can begin by gradually shortening your eating window and step by step extending your fasting phases to get your body used to fasting. While getting started, listen to your body. If you feel unwell or hungry, eat some steamed vegetables to make the transition easier.

Watch how your body reacts to the short break from food. If you feel energised, full and well, you're probably doing everything right. If you have problems such as dizziness or strong hunger, adjust your approach. Remember that not every body reacts the same way and it takes time to adjust to the new eating routine.

During the eating phases, it's important to pay attention to a balanced diet. Go for nutrient-rich foods such as vegetables, fruit, lean protein and healthy fats. Avoid heavily processed foods, sugary snacks and portions that are too big and hard to digest.

During the fasting phases, you shouldn't eat any foods containing calories. Stick to water, unsweetened tea, coffee (without calories) and calorie-free drinks.

Drink enough water during both the fasting and eating phases to keep your body well hydrated. Infused water with cucumber, mint or berries, and unsweetened teas, can help.

Combine intermittent fasting with regular physical activity. Exercise can speed up weight loss, boost your metabolism and support overall wellbeing.

Try to set up a fixed routine for your intermittent fasting. Plan your meals and fasting phases at set times to give your body a clear structure.

Losing weight takes time and patience. Don't expect quick results, work steadily towards your goals. Consistency is the key to success. Stick to your intermittent fasting plan and don't skip meals.

Intermittent fasting mistakes and how to avoid them

Starting too fast

A common mistake is to start straight away with a very small eating window, without getting your body used to fasting. This can lead to cravings, bad moods and low energy. Instead, it's wise to ease into intermittent fasting by gradually extending your fasting window.

Unbalanced diet

Intermittent fasting doesn't mean you should eat anything you like during the eating phases! An unbalanced diet with too many calories, sugar and processed foods can cancel out the benefits of fasting. Make sure you favour balanced meals with plenty of vegetables, healthy proteins and good fats during the eating phases, and watch your portion size.

Not drinking enough

Dehydration can lead to headaches, tiredness and reduced concentration. So always drink enough water, unsweetened tea or other calorie-free drinks.

Not tailoring it to you

Subheading

The effects of intermittent fasting can vary, as every body reacts differently. One mistake is sticking strictly to one particular method even if it doesn't suit your daily life or needs. Find out which approach suits you best and which one feels most comfortable.

Digestion while fasting

During intermittent fasting, digestion carries on, but the processes can change slightly because of the time limits of the eating and fasting periods. Here are a few things to keep in mind about digestion during intermittent fasting:

Digestion while fasting

During intermittent fasting, digestion carries on, but the processes can change slightly because of the time limits of the eating and fasting periods. Here are a few things to keep in mind about digestion during intermittent fasting:

Eating phases

Eating phases

During the eating phases, you have one or more meals depending on the concept, and your digestion runs as usual. Food is broken down in the digestive tract, nutrients are absorbed and the body uses them for energy and other functions.

Fasting phases

Fasting phases

During the fasting phases, digestion runs more slowly because no new food comes in. Instead, the body focuses on processing the nutrients it has already taken in and getting energy from stored reserves.

Stomach emptying & bowel emptying

Stomach emptying & bowel emptying

The speed at which the stomach empties and the gut moves can be influenced by fasting. Often both processes slow down to keep a steady supply of nutrients going during the fasting period.

What to eat between intermittent fasting windows

During the eating phases, it's important to focus on a balanced diet to make sure you get all the nutrients you need and look after your body well. On the other hand, you should cut back on heavily processed foods that are rich in sugar, trans fats and artificial additives. These can undermine the wellbeing benefits of intermittent fasting.

What each of your meals should include:

Easily digestible protein, such as poultry, fish, eggs, tofu or dairy, to stay full for longer and minimise muscle loss during fasting.

Healthy fats, such as avocado, nuts, seeds, olive oil and fish oil for your general wellbeing and to keep you full.

Whole grain foods, such as wholemeal bread, wholemeal pasta, brown rice and oats. They contain fibre to support your digestion and keep your blood sugar level steady.

Vegetables and fruit for vitamins, minerals and antioxidants that contribute to your wellbeing.

Pulses such as beans, lentils and chickpeas for filling fibre and plant-based protein.

Drink enough water to keep your body hydrated and your overall metabolism, especially your digestion, running smoothly.

Which meals are especially suitable

For breakfast, a good option is muesli made with oats, berries, nuts and a drizzle of honey or maple syrup. If you'd rather have something hearty for breakfast, we recommend an omelette with eggs, filled with a variety of vegetables such as spinach, peppers, tomatoes and mushrooms. Greek yoghurt with fruit and nuts is also a great choice. For lunch or dinner, stuffed vegetables, such as peppers or courgettes with a mix of lean protein, work well. Colourful salads with a variety of vegetables, lean protein (chicken, fish, tofu), healthy fats (avocado, olive oil) and a light dressing are always a good idea. Wholemeal pasta with tomato sauce and vegetables can also make a balanced, filling meal!

Remember that the quality of the food you eat plays an important role in your wellbeing and in the success of intermittent fasting. Make sure to include a balanced diet with a variety of different, unprocessed foods to make sure you get all the nutrients you need.

Who shouldn't fast

Intermittent fasting isn't suitable for everyone, especially people with certain health conditions or in certain life circumstances. This includes pregnant and breastfeeding women, who have an increased need for nutrients and so shouldn't make extreme changes to their diet without a doctor's approval. Children and teenagers who are still growing should also skip fasting. Conditions where you should also avoid fasting, or talk to your trusted doctor or a nutritionist about it first, include eating disorders, heart problems and high blood pressure, gastrointestinal conditions and thyroid conditions. During times of heavy stress, intermittent fasting can also mean extra stress for the body, so a careful weighing-up makes sense here.

Who shouldn't fast