Intermittent fasting, also known as "intermittent fasting," has been trending for a few years.

With this type of fasting, eating and fasting phases alternate hourly or daily.

The most well-known is the 16:8 fast, in which eight hours of eating and (usually overnight) no food are eaten for 16 hours.

Intermittent fasting should not only let the kilos tumble, but also have a number of positive effects on the organism.

Last but not least, it is said to have anti-aging effects.

The fact that intermittent fasting can have a positive effect on health was noticed as early as 1907 by the American fasting doctor Edward Dewey.

He recommended skipping breakfast because it helps reduce weight and strengthens nerves and muscles.

Today it has been scientifically proven, at least in animal experiments, that not eating regularly strengthens the immune system, reduces the risk of developing type 2 diabetes and prevents both neurological and cardiovascular diseases.

Even long fasting is not harmful to health

But fasting is also being intensively researched beyond animal experiments.

Human studies have so far mostly focused on overweight people or other patient groups.

These different study populations and the lack of a control group in some cases have so far made it difficult to make generalized statements about the effects of intermittent fasting, especially on healthy people.

The heterogeneity of the study results is not least due to the fact that there are many different forms of short-term fasting: followers of the 5:2 method eat less on two days a week, others fast alternately and remain hungry every other day, and some do without supper.

According to Gunda Backes from the German Society for Nutrition, this "evening fasting" should "relieve the insulin level,

promote weight loss and improve sleep quality”.

But what about the other fasting methods?

Are they also recommended for healthy people?

This is exactly what Frank Madeo, biochemist and professor at the Institute for Molecular Biosciences at the University of Graz, together with Slaven Stekovic and his team, took a closer look at.

The scientists examined the effects of alternating fasting on various bodily functions in healthy subjects.

Madeo is a world-renowned fasting expert and is particularly concerned with the molecular mechanisms of metabolic regulation.

The study, which was published in the journal Cell Metabolism in 2019, recruited 90 participants, 30 of whom had been doing alternating fasting for six months.

Half of the remaining participants maintained their lifestyle, the other half fasted every other day.

The evaluation of the data not only showed a weight reduction in the fasting group,

cholesterol levels, blood pressure and the values ​​of various inflammatory parameters were also reduced.

Another result: anyone who fasts alternately for longer than six months does not harm their health.

Finally, an increase in ketone bodies was also measured in the fasting group.

Frank Madeo explains: "These arise as a by-product of fat burning in the event of a carbohydrate deficiency and are suspected of having age-protective effects" - i.e. protecting cells from aging.

Cells clean themselves

The fact that fasting can slow down aging was first observed in rats in the 1980s.

An alternating fasting diet increased their life expectancy by 80 percent.

Findings from the past ten years have shown that the cell's self-cleaning processes, also known as autophagy, are responsible for a longer lifespan.

"Fasting is the most powerful natural way to stimulate autophagy," said Mark P. Mattson, a neurobiologist and professor at Johns Hopkins University in Baltimore and known for his research on aging.

During autophagy, which begins after a fasting interval of around 14 to 16 hours, so-called lysosomes become active, cell organelles that are responsible for breaking down damaged proteins or old cell components.

Autophagy is particularly important for cells of the brain and central nervous system.

It is assumed that deposits in these areas can lead to neurological diseases of old age such as dementia or Alzheimer's.

Whether these processes prolong life is still pending.

However, one thing is clear: the positive effects of intermittent fasting on health are increasingly being confirmed empirically.

But if you don't like eating by the clock, another remedy can be recommended: According to Mattson, many of the effects of intermittent fasting are comparable to those that result from physical activity.

However, only further studies will be able to provide information on whether fasting can replace sport.