Diet that mimics the effect of fasting WITHOUT starving yourself could add years to followers’ lives, trial shows

A diet that mimics the effect of fasting without starving yourself can extend your life by years, a study suggests.

Researchers found that people who followed the fasting-mimicking diet (FMD) for 15 days reduced their biological age by over two years on average.

Tests also showed they had a lower risk of diabetes, heart disease and stroke, based on biomarkers in their blood.

The FMD diet involves eating around fewer than 1,000 calories – made up of low-fat foods, soups, energy drinks and supplements.

It is said to trick the body into thinking it is fasting, releasing enzymes and other chemicals in the body that have been linked to longevity.

Participants ate a FMD made up of plant-based soups, energy bars, energy drinks, chip snacks, and tea portioned out for five days, as well as a supplement providing high levels of minerals, vitamins, and essential fatty acids

Professor Valter Longo, a biologist from the University of Southern California in Los Angeles, who developed the diet in the new study and is the lead author, said: ‘This is the first study to show that a food-based intervention that does not require chronic dietary or other lifestyle changes can make people biologically younger.’

The diet used in the study involved three cycles of five days on the FMD diet.

Day one saw the participants eat 1,100 calories, while days two to five saw them consume eat around 720 calories daily.

Their diet during these days also consisted of healthy chip snacks and tea.

The diet is made up of 34 percent carbohydrates, 10 percent protein and 56 percent fat for the first day, and then seven percent carbohydrates, nine percent protein, and 44 percent fat for the other days.

Participants then got to eat their usual diets for 25 days. 

Both groups contained men and women aged between 18 and 70.

After three months, researchers analyzed blood samples from participants, which showed that patients in the FMD group had lower diabetes risk factors, including less insulin resistance and lower blood sugar levels.

Chronological age is how long you have  been alive, whereas biological age is how old your cells and tissues are. It is a significant metric because it shows how susceptible you may be to disease.

MRI scans also showed a decreased in abdominal fat and fat in the liver, which are associated with a reduced risk of metabolic syndrome, which increases the risk of heart disease, stroke and diabetes.

Previous research has suggested FMD cycles can even lower risk factors for cancer.

The FMD cycles also appeared to increased participants’ lymphoid-to-myeloid ratio, which is an indicator of a more youthful immune system.

Further analyses revealed that FMD participants had lowered their biological age – a measure of how well one’s cells and tissues are functioning, as opposed to chronological age – by 2.5 years on average.

Researchers believe the FMD has ‘rejuvenating effects on the immune system’. In previous studies in mice, the diet caused a ‘rejuvenation of the blood profile.’

The FMD diet also switches cells throughout the body to a protected ‘anti-aging mode’ — an effect which endures beyond the fast.

The body has what is known as ‘nutrient-sensing’ pathways, which control autophagy – kind of ‘housekeeping’ of the body’s cells.

It is constantly going on in the body and removes unwanted byproducts of cell processes.


The more autophagy that happens, the better you feel and the lower the risk of future health problems.

The FMD diet accelerates autophagy, so more byproducts and ‘bad’ cells in the body are disposed of that cause disease and aging.

The study was published in the journal Nature Communications.

It is supposed to mimic the effects of a water-only fast while still offering essential nutrients.

A water-only fast is where you only drink water for a period of time and ingest no other food or beverages. People water fast for weight loss or to lower blood pressure.