But how can we do that? Since forever, fasting has been used to increase longevity. Yet the challenge of reducing calorie intake is enough to scare most of us away. So what if you could make your body think you are fasting without starving yourself?
That is what the biogerontologist and cell biologist Valter Longo has created. He is one of TIME’s 50 most influential people in healthcare. His groundbreaking research on aging and his fasting mimicking diet (FMD) concept have transformed how we think about health and longevity.
His book - "The Longevity Diet" (3) - is what is inspired us to create reSET Program, a 5-day fasting mimicking program.
1. Understanding Fasting Mimicking Diets (FMD)
Valter Longo studied centenarians and combined it with studies of populations, clinical trials and research to understand how to live longer and healthier lives in order to "die healthy"(3).
Definition and fundamental principles
For his doctoral work, Dr Longo joined the pathologist Roy Walford at UCLA and studied the effect of caloric restriction. During his studies he saw how mentally challenging and isolating it was be to be on such a restricted calorie diet.
Looking for an easier solution to delay aging and prevent disease, he developed a protocol that mimics fasting: the fasting mimicking diet, also called FMD. The goal was to achieve the same results as a water fast by putting together a specific diet which is low in proteins and sugars, and rich in good fats. This specific macronutrient approach had to have the same benefits of a fast but ensure proper nourishment (3).
The reSET program is based on the FMD concept and provides you with nourishing soups, breakfasts and snacks that follow Longo's protocol.
Comparison with other fasting diets
There is a lot of data on long-term fasting from either water fasting diets or low calorie diets that need to be executed at specialised clinics and under medical supervision. In contrast, Longo wanted to create a 5-day protocol that (3):
- provides sufficient calories to be safe at home without the supervision of a doctor or nutritionist
- is enjoyable with a diversity of foods and in-between snacks
- is 100% vegan, refined sugar free and gluten free
- is as effective as fasting executed at specialised clinics
Underlying biological mechanisms
The fasting mimicking diet, as demonstrated in animal studies and by now in human clinical trials, can reverse aging, promote healthy longevity and rejuvenate the body by:
- putting our cells in a protected anti-aging mode
- enabling autophagy (cellular clean-up) and replacing damaged cells components by new functioning ones
- destroying damaged cells
- switching the body into fat burning mode, more specifically abdominal and visceral fat burning
2. Benefits and Advantages of the Fasting-Mimicking Diet
In addition to the biological mechanisms stated earlier, FMD has also shown to reduce risk factors for diabetes, cancer and cardiovascular diseases (1). As of 2021, approximately 537 million people worldwide are living with diabetes (2). Type 2 diabetes accounts for about 90% of these cases.
Improvement in insulin sensitivity
Type 2 diabetes typically happens when the body becomes resistant to insulin or doesn't produce enough insulin to maintain normal blood sugar levels. This condition is influenced by factors such as poor diet high in processed and sugary food, lack of physical activity, weight issues, genetics, and aging, with lifestyle decisions playing a crucial role in its development.
The FMD can improve insulin sensitivity by promoting metabolic shifts that improve the body's ability to regulate blood sugar in an effective way. Here is how:
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By lowering the calorie intake for a short period, FMD decreases insulin secretion, allowing insulin receptors to become more responsive over time.
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Excess visceral fat contributes to insulin resistance. FMD has been shown to reduce fat storage, especially around the liver and waist, which helps improve glucose metabolism.
- Chronic inflammation is a key driver of insulin resistance. FMD reduces inflammatory markers, improving overall metabolic health.
Impact on weight loss and metabolic management
Fasting supports weight loss through a reduced calorie intake and metabolic adaptation, leading to reduced body fat while maintaining muscle mass. It has also been shown to reset metabolism by improving key metabolic markers.
Effects on disease prevention and longevity
The fasting mimicking diet has been shown to extend lifespan and promote healthy aging by activating cellular repair processes, reducing disease risk, and improving metabolic efficiency.
The main longevity benefits come from cellular rejuvenation, metabolic optimization, and reduced age-related disease risks.
The Zoe Science & Nutrition Podcast recently interviewed Valter Longo on could fasting increase your lifespan?
3. Implementing a Fasting Mimicking Diet
Regularly following a 5-day fasting-mimicking diet like the reSET program can support healthy weight management, improve metabolic health, and prevent muscle loss—without the drawbacks of continuous low-calorie dieting, such as yo-yo weight fluctuations.
Recommended protocols for an effective cycle
The FMD protocols are based on scientific studies, clinical trials, and expert recommendations, particularly from research conducted by Dr. Valter Longo and his team at the University of Southern California (USC) Longevity Institute.
| Goal | Frequency |
| Metabolic Reset (Weight Loss, Insulin Sensitivity, Diabetes) | Monthly for 3-6 months, then quarterly |
| Longevity & General Health Maintenance | Every 3-4 months |
| Immune System Regeneration | Every 1-3 months (e.g., post-infection or immune-related issues) |
| Brain Health (Neuroprotection, Alzheimer’s Prevention) | Every 3 months |
| Cancer Risk Reduction | Every 2-3 months (as per IGF-1 & mTOR reduction studies) |
The calorie structure is as follows:
Day 1: 1'100 calories (10-15% protein, 50-55% fat, 35-40% carbs)
Day 2-5: 700-800 calories (10-15% protein, 50-55% fat, 35-40% carbs)
Beyond the diet:
Day 6-7: gradually increase calories to 1'500-2'000 and follow a Mediterranean diet.
Foods to prioritize and avoid
- Complex carbohydrates from vegetables like spinach, broccoli, tomatoes, carrots, pumpkin, sweet potatoes, beetroots and refined sugar free like dates in small quantities.
- Healthy fats from nuts, seeds, olive oil and coconut.
- Plant-based proteins from nuts and seeds.
- Whole foods like vegetables and berries
Avoid processed foods, refined sugar, gluten and any inflammatory animal products like meat and milk. Do not consume alcohol and reduce coffee to maximum one cup per day without milk and sugar.
A fruit juice-based FMD is not possible because it does not provide the same metabolic benefits as the standard FMD, which is designed to mimic fasting while maintaining low glucose, insulin, and IGF-1 levels.
Additional tips for success
- Stay hydrated by drinking plenty of water & herbal teas.
- Balance electrolytes by ensuring adequate sodium, potassium, & magnesium intake. We provide electrolyte powders in the reSET program.
- Avoid overeating after your diet by gradually reintroduce calories with whole foods. We recommend using the reBUILD program for that crucial refeeding phase because it provides you with balanced & nourishing meals high in fibres, and refined sugar and carbs free. The program will help you have a structured and reliable diet for the next 5 days.
- Remain mindful when it comes to exercise by avoiding intense workouts on low-calorie days; focus on light movement like yoga or walking. During the reSET program, we give you access to on-demand workout that are the perfect combination of mindfulness and training to keep you motivated but not over-exhausted.
- Avoid social interactions when it's the first time you do it.
Our team at Eat by Alex regularly use the FMD reSET program and in this blog you can find out how it went for two of our colleagues.
Optimal timing for women
Unfortunately, there is limited scientific research specifically addressing the optimal timing for fasting in relation to women's menstrual cycles. The follicular phase (post-menstruation), energy levels typically rise, which might make it a more suitable time for fasting. Conversely, the luteal phase (pre-menstruation) often brings about increased hunger and lower energy levels, suggesting that intensive dietary restrictions during this time could be more challenging.
Who should do a fasting mimicking diet
If you want to:
- lose weight
- detox liver
- improve gut health
- reboot digestion
- achieve autophagy
- increase lifespan
Who shouldn't take part
If you are:
- pregnant or breastfeeding
- underweight (BMI less than 18.5)
- taking medications
- feeling weak
- sick
- an athlete in training or competition
- allergic to nuts, seeds, or grains
or if you have:
- diabetes, cancer, cardiovascular, autoimmune or neurodegenerative disease - please consult your physician for advice, permission and approval
- liver or kidney disease
- low blood pressure or high blood pressure
- history of eating disorders
- thyroid disorders, particularly Hashimoto's or hypothyroidism
Consult and seek approval from your doctor or nutritionist before signing up for a FMD program.
4. Studies and Research on FMD
Fasting-mimicking has been extensively studied in animals and is now supported by numerous human clinical trials.
Results from recent clinical trials
1. This ARTE documentary is an easy summary on the science of fasting | in German.
2. USC study shows how cycles of a fasting-mimicking diet reduce insulin resistance, liver fat, immune system aging, and biological age in clinical trial patients. (4)
3. Clinical trials have found that short-term, severe calorie restriction through FMD is safe and may enhance the body's antitumor immune response, indicating potential as a complementary approach in cancer therapy. (5)
4. Recent research indicates that FMD cycles can reduce risk factors for diseases such as diabetes, cardiovascular conditions, and neurodegenerative disorders. For instance, a study by the National Institute on Aging found that FMD was associated with reduced risk of diabetes, decreased liver fat, and enhanced immune function. (6)
White paper by Maven Health
We have partnered with Maven Health to test the benefits of our reSET 5-day fasting mimicking program. Through Maven's saliva testing of metabolites before and after the reSET program. (7)
reSET is nutritionist-approved
Peak Nutrition GmbH reviewed and approved the reSET Program. This not only validates the program’s effectiveness but also its safety—ensuring you can fast with confidence. (8)
Eat by Alex customer testimonials
Future perspectives and innovations in the field
Combining FMD with exercise, pharmacotherapy, or cognitive training, is being explored to enhance overall health outcomes. This integrative approach aims to leverage the synergistic effects of multiple therapies.
The use of wearable devices and digital health platforms enables real-time monitoring of biomarkers during FMD cycles, providing data to refine protocols and improve adherence.
Large-scale clinical trials and long-term studies are underway to assess the safety, efficacy, and potential risks of FMD in various populations, providing evidence-based guidelines for its implementation.
5. References
(1) Longo et al. (2017) in Science Translational Medicine
Results are based on a clinical trial that Valter Longo and team conducted over a randomised study of one hundred patients. Subjects adopted a FMD for five days a month over a period of three months.
The remarkable outcomes:
- decrease body weight by specifically losing abdominal fat
- increase muscle mass relative to body weight
- reduce glucose baseline in prediabetic subjects
- decrease blood pressure in subjects with moderate high blood pressure
- decrease cholesterol in subjects with high cholesterol
(2) https://diabetesatlas.org/atlas/tenth-edition/
(3) The Longevity Diet by Dr Valter Longo
(4) https://gero.usc.edu/2024/02/20/fasting-mimicking-diet-biological-age/
(5) https://www.aacr.org/patients-caregivers/progress-against-cancer/fasting-mimicking-diet-found-safe-and-potentially-helpful-to-cancer-patients
(6) https://www.nia.nih.gov/news/can-fasting-reduce-disease-risk-and-slow-aging-people
(7) https://www.biorxiv.org/content/10.1101/2024.12.29.630652v1
(8) https://eatbyalex.com/blogs/news/peak-nutrition-gmbh-reviews-reset