Fasting While Eating: The Fasting Mimicking Diet

Joel Kahn
4 min readFeb 22, 2019


Can you make money while sleeping? Build muscle while lying on a hammock? Finish your work project while partying at the bar? These things seem too good to be true.

Here is another one. How about gaining the benefits of fasting, including losing fat pounds, while eating? The good news is that this is no fantasy and is the hottest science in the research on fasting. And it is something you can start using this week.

The articles on fasting are everywhere but it is easy to be confused by terms used. What’s the difference between intermittent fasting, water fasting, juice fasting, and time restricted feeding? The potential medical benefits from taking a break from eating for a period of time have been suggested in both animal and medical research projects. For example, in one of the Blue Zones of longevity, Okinawa, the expression Hara Hachi Bu (eat until you are 80% full) is a part of the culture. Can you match this or even exceed the purported benefits of the Okinawan Diet while “cheating” the system by eating a menu of foods that mimick benefits of fasting?

Yes, Virginia there is a fasting mimicking diet (FMD) and it is proven path to the world of stem cell based regenerative medicine. FMD is the result of decades of pioneering work on longevity by Valter Longo, Ph.D. and his team at the University of South California. Dr. Longo is recognized around the globe as a leading expert on longevity. Dr. Longo developed the FMD for humans after over 20 years of groundbreaking research showing it allowed the benefits of fasting without the limitations of a water fast.

The Basics of the FMD
The FMD program is done over 5 consecutive days. The program consists of high quality foods that provide 1,100 calories on the first day and 800 calories the next four days. The nutrients have been precisely researched and include meals of plant-based whole foods like nuts, olives, teas, and soup mixes. Overall the food in the FMD program comprises about 60% of calories from fats, 10% from protein, and 30% from complex carbohydrates. The program is gluten free and without added sugars or animal proteins. While following the FMD, exercise and alcohol are omitted and coffee is limited or eliminated. The program contains nuts so it’s not appropriate for those with a nut allergy.

What Happens with FMD in Humans?
After years of experiments with FMD in animal models that showed benefits on metabolism and life span, Dr. Longo’s team analyzed the effects in a human clinical trial that was published in 2017.

One hundred healthy subjects participated in the study. Half followed the FMD consecutive five days a month for three months in a row, and the other half ate their usual diet. Profound benefits were seen in terms of weight loss, visceral (belly) fat loss, lower blood pressure, blood sugar, and blood cholesterol, and markers of inflammation.

Even more profound was the decrease of insulin like growth factor 1 (IGF-1), which is a biomarker that may promote cancer growth. There also was an increase in stem cell production, which is a marker for regeneration of cells.

In fact, the FMD program is now patented as a program that promotes regenerative and rejuvenating changes, which is unique from all other data for fasting programs.

Results of the FMD in Animals

In preliminary studies with FMD in mice, remarkable brain changes were identified. Mice fed the FMD experienced extended longevity, lowered visceral fat, reduced cancer incidence and skin lesions, rejuvenated the immune system, and retarded bone mineral density loss. In old mice, FMD cycles promoted brain growth (hippocampal neurogenesis). Researchers were able to demonstrate improved cognitive performance. Overall, these preliminary animal data are encouraging.

Where Do You Get the FMD?

The FMD is available through a start-up called L-Nutra and can be ordered from practitioners. There are contraindications like diabetics on insulin and those on multiple medications were the limited calories might drop blood sugar severely. Pregnant women and the elderly should not follow the FMD.

I advise my patients that if they want to achieve the published results, they should follow the FMD for 5 consecutive days returning to a healthy diet option like a whole food plant diet or Dr. Longo’s Longevity Diet for the rest of the month and do that 3 months in a row. I have seen amazing improvements in weight, waist measurements, lab markers, blood pressure, and mental alertness.

Why does the FMD work?

The FMD works because of the nutri-technology that Dr. Longo used. By avoiding added sugars and amino acids from animal foods, along with the reduced calories, pathways known to promote aging are inhibited temporarily. Furthermore, stem cell-based regeneration results. A gentle ketosis is induced for a short period of time. I have “tricked” my body many times with the FMD. I can still work long days and feel great. The scientific advantages of using the FMD are profound and the science is expanding worldwide.

Do yourself a favor. Fast while eating and enjoy stem cell-based regeneration.



Joel Kahn

Professor of Cardiology, Summa cum Laude grad, Kahn Center for Longevity and GreenSpace Cafe. @drjkahn. Author The Plant Based Solution NEW