My first FMD -Fasting Mimicking Diet, day 0

FMD (Fasting Mimicking Diet; Valter Longo, ProLon) is a 5-day dietary protocol that is low in calories, low in protein, and predominantly plant-based. Nutrient intake is kept below the nutrient-sensing threshold, thereby mimicking a fasting state without complete food deprivation. Compared with water-only fasting, it is considered safer and more controllable, while still capable of triggering cellular autophagy and other metabolic and regenerative processes.

This is a record of my decision to personally experience FMD. The decision was not impulsive, but rather based on several years of consideration of my own health profile, scientific evidence, and a careful assessment of risks and benefits.

First, there is scientific evidence. A 2024 Nature publication reported that in healthy adults, completion of three FMD cycles was associated with reduced insulin resistance and multiple pre-diabetes markers, decreased hepatic fat content (as assessed by MRI), and an increased lymphoid-to-myeloid ratio—an indicator of immune system aging. Using a validated biological age measure predictive of morbidity and mortality, three FMD cycles were associated with a median reduction of approximately 2.5 years in biological age, independent of weight loss.

Second, there is my personal metabolic background. Over the past few years, my HbA1c has shown a gradual upward trend, and continuous glucose monitoring (CGM) has revealed notable post-prandial glucose spikes. I hope FMD may help improve insulin sensitivity.

Third, there is my cancer-risk background. Ten years ago, I underwent surgery for a chest tumor. As a result, I have remained attentive to cancer prevention and cellular-level repair mechanisms. I am particularly interested in the emerging research on FMD related to autophagy activation, cellular renewal, and potential anti-cancer effects.

There is also a very practical reason. Some of my friends and family members may have a greater need for this type of nutritional intervention than I do. By experiencing it myself, I hope to gain a more grounded and realistic understanding, so that—when appropriate—I can discuss it more responsibly with those who may benefit.

It is important to be clear: FMD is not a mainstream or standardized medical therapy, and research is still ongoing. I am not recommending it to others. This is solely a personal experience and an honest account.

Regarding risk assessment, a 5-day low-calorie intake (approximately 700–1100 kcal/day) does carry inherent risks. For this reason, I consulted my personal physician in advance and established contact with a registered dietitian from L-Nutra. Daily Zoom guidance recording is provided. Baseline assessments included blood work, body weight, body fat, and waist-to-hip measurements have been obtained. This program has been discussed and promoted for several years at lifestyle medicine conferences, which contributes to my level of trust in its structure.

For the coming days, I have set clear boundaries. During FMD, I will avoid coffee and minimize additional stressors, as the body is already in a low-energy, autophagy-associated stress state. I will not perform high-intensity training. I will prioritize sleep and emotional stability. Supplements are simplified to vitamin D, magnesium, and B12 only; all others—including fish oil and eye-health supplements—are temporarily paused. Hydration is emphasized: at least 32 ounces per day (my personal goal is 50 ounces), starting with a glass of water upon waking. Caffeine-free teas included in the package (such as red rooibos) are allowed, as is limited decaffeinated coffee. Barley tea is avoided to minimize additional carbohydrates. I am using the expanded-variety version (not the most expensive option), with fixed daily meals. Day-one meals and supplements have been reviewed in advance, and I will maintain a three-meal rhythm. I will also focus on staying warm. CGM monitoring will begin tomorrow morning.

From a mindset perspective, I am approaching this with mindfulness and observation. This FMD is meant to be a dialogue with my body, not a confrontation. My hopes include improved insulin sensitivity; reduction of abdominal and visceral fat (with modest reduction in leg fat if it occurs); comprehensive preservation of facial, neck, chest, and hand fat; removal of aged or dysfunctional cells with support for new, functionally robust cells; improved health of the brain, skin, hair, nails, and gut; enhanced vision, hearing, smell, and taste; improved attention and memory; greater emotional stability and gentleness; and a reduction in food noise, allowing more space for introspection and reflection.

In the days following completion of FMD, I plan to replenish energy carefully, using high-quality, whole-food, plant-forward nutrition to support cellular repair and functional recovery, while ensuring weight and overall status remain stable.

This is an attempt with boundaries, support, and awareness. It is not about pushing limits, but about listening to the body and recording the rhythms of life.