How does intermittent fasting work? - Lose weight part-time

It's the dream of anyone on a diet: eat most of the week, eat what you want, and only limit your calorie intake on one or two days and still lose weight. Believe it or not, intermittent fasting not only benefits your figure, but also stabilizes blood sugar levels, reduces inflammation and keeps your heart healthy.

There are various forms of intermittent fasting. Numerous studies have shown the many positive effects on health and general well-being.

Some people fast for a few hours every day or skip meals two days a week. Intermittent fasting is a relatively simple way to improve your health and lose weight successfully.

In this comprehensive guide, we explain the options for interval fasting, the benefits and other interesting facts worth knowing about this weight loss method.

Contents

• What is intermittent fasting?
• How long do I have to do intermittent fasting?
• What can I eat during intermittent fasting?
• 6 benefits of intermittent fasting
• The best approaches to intermittent fasting
• Precautionary measures
• Concluding remarks

What is intermittent fasting?

Intermittent fasting is also known as cyclical fasting and has been growing in popularity for several years. More and more scientific studies are revealing new benefits of this form of nutrition.

In 2016, scientists conducted a study on cell metabolism entitled "Fasting, Circadian Rhythms and Time-Restricted Feeding". They investigated how fasting enables us humans to cover our energy requirements with ketone bodies and fat stores rather than with glucose. The results showed that both periodic and intermittent fasting have benefits for our health, ranging from prevention to better treatment of diseases. Even diets that only mimic fasting can produce similar changes in the body.

However, intermittent fasting is not a modern invention. It has been practiced for centuries in times when food is scarce. Fasting also plays an important role in many religions. Muslims, for example, fast once a year for a whole month (Ramadan) from sunrise to sunset.

It is not easy to define intermittent fasting precisely, as there is more than just one form. People around the world fast in very different ways. They adhere strictly to a precise schedule in order to achieve the desired physical or spiritual goals.

How does it work? 

Thanks to intensive research, we know that intermittent fasting improves our health in two ways:

• First of all, the diet ensures that oxidative stress is reduced in all body cells.
• It also strengthens the body's ability to cope with stress at a cellular level. Intermittent fasting activates cellular stress pathways - similar to very mild stress factors. This gently stimulates a stress response in the body. As this happens permanently, the body hardens itself against cellular stress and is less susceptible to cell ageing and the development of diseases.

How long do I have to do intermittent fasting?

If the positive effects on health and lifespan are indeed confirmed, there is only one answer to this question: ideally for a lifetime . An important prerequisite for intermittent fasting is a balanced, healthy diet. Then there is no reason why it should not be used permanently.

The most common forms of intermittent fasting include:

• Alternate-day fasting: You only eat every other day. On fasting days, some people abstain from all food, others eat only very small amounts, usually no more than 500 calories. On the other days, you eat normally, but healthily!
• Warrior diet: In this form, you eat only fruit and vegetables during the day and a large meal in the evening.
• 16-8 method ("eating according to a schedule"): You fast for 16 hours each day and eat in the remaining eight. Most people don't eat anything after dinner and skip breakfast the next morning.
• Eating-fasting-eating With this method, you fast one or two days a week for 24 hours. For example, you eat dinner on one day and then nothing else until the next evening meal. On the other days, you should make sure you have a normal calorie intake.
• 5:2 diet: You eat normally five days a week. The remaining two days are your fasting days, on which you consume no more than 500-600 calories.

 

What can I eat during intermittent fasting?

As intermittent fasting is not a diet, you can basically eat anything. What was previously eaten throughout the day is now consumed in a shorter period of time. Although sugary and fatty foods are not prohibited, they are not good for the body and should therefore be reduced. In the morning after getting up, only water, tea or black coffee are allowed until the first meal.

6 benefits of intermittent fasting

1. promotes weight loss

One of the greatest benefits of intermittent fasting is its ability to boost fat burning and help you shed pounds. This is why many people prefer intermittent fasting to conventional diets. You don't have to weigh your food precisely and keep an eye on your calorie intake, etc.

Intermittent fasting forces the body to burn fat reserves and thus ensures rapid weight loss. When you eat, your body uses glucose (sugar) as its main source of energy and stores excess glucose as glycogen in the muscles and liver.

As soon as you do not continuously supply your body with glucose, it begins to utilize stored glycogen as energy. If these stores are also exhausted, the body looks for alternative sources of energy and finds them in the form of fat cells, which it then breaks down and burns.

This is similar to the keto diet, where you deprive your body of carbohydrates, forcing it to use stored fat as energy.

• In 2015, scientists evaluated various studies on the effect of alternate-day fasting. They came to the conclusion that the subjects' body weight was reduced by 7 percent and their body fat percentage by 5.5 kg. You can achieve similar results with all-day fasting, reducing body weight by up to 9 percent. So far, there are no reliable findings on how this method affects your muscles.
• Another study focused on the 16-8 method and concluded that it can significantly reduce fat mass while maintaining muscle mass and strength. 

2. improves the blood sugar level

After eating, carbohydrates are converted into glucose (sugar) by the body and released into the blood. A hormone called insulin is then responsible for ensuring that the glucose enters the cells from the blood and is available there as energy.

However, if you suffer from diabetes, insulin does not work as intended. This can lead to high blood sugar levels coupled with other symptoms such as tiredness, thirst and frequent urination. Consult your doctor or alternative practitioner to find out whether intermittent fasting is suitable for you.

• Some studies have shown that intermittent fasting benefits blood sugar levels and keeps them under control. Sharp spikes up or down could be avoided.
• In one study, diabetics fasted for an average of 16 hours a day over a period of two weeks. This not only led to weight loss and a reduced calorie intake, but also lowered blood sugar levels.
• Another study showed that fasting can reduce blood sugar levels by 12 percent and insulin levels by almost 53 percent. If insulin is prevented from accumulating, it can work better. The body remains receptive to the effect.

3. keeps your heart healthy

One of the most impressive benefits of fasting is its positive effect on heart health.

• Studies show that intermittent fasting promotes heart health by reducing certain risk factors for heart disease.
• One study showed an influence on various aspects of heart health. The HDL level ("good" cholesterol) is increased and both the LDL("bad" cholesterol) and triglyceride levels are lowered.
• The results of a study published in the Journal of Nutritional Biochemistry show that intermittent fasting causes an increase in adiponectin levels. Adiponectin is a protein that is involved in fat and sugar metabolism and protects against heart disease and heart attacks. 
• In one study, rats fasted every other day. Their chances of surviving a heart attack increased by almost 66 percent compared to those who were fed normally.

4. relieves inflammation

Inflammation is a normal immune response of the body to injury. However, chronic inflammation can lead to chronic disease. In some studies, inflammation has been linked to conditions such as heart disease, diabetes, obesity and cancer.

• The results of a study were published in the journal "Nutrition Research". 50 test subjects fasted during Ramadan. It was observed that some inflammatory markers decreased in the subjects during this time. 
• Another study from 2015 came to the conclusion that a longer period of fasting at night is associated with an improvement in inflammatory markers. The specialist journal "Rejuvenation Research" states that alternate-day fasting can reduce markers for oxidative stress.

Further research is needed, but these studies provide promising evidence that intermittent fasting can reduce inflammation and combat chronic diseases.

5. protects the brain

However, intermittent fasting can not only keep the heart healthy and prevent illness. Some studies suggest that the brain is also protected.

• In an animal study, intermittent fasting strengthened cognitive function and protected against changes in memory performance and learning ability compared to the control group. In another animal study with mice, the scientists found that intermittent fasting influences certain proteins in the brain that are involved in brain ageing.

In addition, the anti-inflammatory effect of intermittent fasting could slow down the progression of neurodegenerative diseases such as Alzheimer's.

Some scientists are also convinced that fasting promotes autophagy, i.e. the process that takes place during cell renewal and in which the body utilizes unusable cell components. However, the evidence for this is still very thin, so further research is needed.

6. reduces hunger

Leptin is a satiety hormone that is produced in fat cells and signals to the body when it has taken in enough food. Leptin levels fall when you are hungry and rise as you become increasingly full.

As leptin is produced in fat cells, people who are overweight or obese tend to have higher leptin levels in their bodies. However, too much leptin can lead to leptin resistance, meaning that those affected no longer feel full.

• A study of 80 test subjects whose leptin levels were measured during intermittent fasting showed that the level drops during the fasting period.

A low leptin level could mean reduced leptin resistance, less hunger and possibly greater weight loss.

 

The best approaches to intermittent fasting

As already described, there are many different forms of intermittent fasting, so you can choose the one that best suits your lifestyle and daily routine. It is best to simply try out the different forms to see which one works best for you.

The 16-8 method is easiest for beginners. You limit the time in which you eat. This means that you normally skip your snack in the evening after dinner and breakfast the next morning. For example, if you do not eat between 8 pm and 12 noon, you have already fasted for 16 hours.

Bear in mind that intermittent fasting is less of a diet and more of a lifestyle change. Unlike typical diets, you don't have to count points or calories or write down what you have eaten day by day.

You get the full benefit of intermittent fasting if you consume healthy, wholesome foods that provide you with as many nutrients as possible.

You should also listen to your body. So if you feel weak or tired because you haven't eaten anything all day, increase the amount of food you eat a little or treat yourself to a light snack. Or try one of the other methods and find the one that really suits you. Talk to your doctor or alternative practitioner.

Precautionary measures

Although intermittent fasting offers many benefits for your health, this diet is not suitable for everyone. Some people should therefore not use it.

For example, if you suffer from low blood sugar levels, going without food for a whole day could cause symptoms such as shakiness, palpitations and tiredness. As a diabetic, you should discuss with your doctor whether intermittent fasting is suitable for you.

If you have suffered from eating disorders in the past, this diet is also not suitable for you, as it can trigger unhealthy behavior and corresponding symptoms. Intermittent fasting is also not recommended for children and adolescents who are still growing.

If you are ill, you should also think carefully about whether you want to fast during this time. Your body needs a steady stream of nutrients and energy to get well.

Is intermittent fasting suitable for women? If you want to get pregnant, you should avoid intermittent fasting and instead focus on a nutrient-rich diet with plenty of vitamins and minerals. Some women develop hormonal imbalances if they fast for a longer period of time. If you are one of them, you should only fast a few days a week and not every other day, for example.

Intermittent fasting can contribute to a worsening of the state of health in the case of existing biliary diseases and should therefore be avoided.

Last but not least, studies show that fasting affects thyroid hormone levels. So if you have problems with your thyroid gland, you should not fast to avoid fluctuations in these important hormones.

If you are physically active, you can fast and still do sport. This also applies to your fasting days. However, you should not exceed your limits and drink plenty of water. However, if you are fasting for longer than 72 hours, you must limit your physical activity.

Concluding remarks

• If you are looking for a way to boost your fat burning and lose weight faster while doing something good for your health, interval fasting could be just the thing for you.
• This not only reduces your weight and promotes fat burning, but also ensures better regulation of your blood sugar levels, protects your brain, keeps your heart healthy and reduces inflammation.
• You can choose between different forms of intermittent fasting and decide on the one that suits you best.
• You should not fast if you have certain pre-existing conditions. However, for many people this is a good way to do something for their health.

 

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