A fasting mimicking diet (FMD) is a low-calorie, low-protein, low-carb eating plan designed to mimic the effects of fasting while still providing some nutrients. The most well-known version is Dr. Valter Longo's 5-day cycle, which reduces calories by 75% and restricts protein to 9-11%. You can do this at home with proper planning.
The FMD triggers cellular cleanup processes called autophagy, where cells digest and recycle damaged components. This differs from traditional fasting because you consume specific foods rather than abstaining entirely. Studies show it may improve metabolic health, reduce inflammation, and support longevity.
The diet consists of:
Dr. Longo's protocol uses his proprietary food kits, but you can replicate it with whole foods. For example, a typical day includes:
People use FMD for weight loss, metabolic health, and longevity. Research suggests it may reduce risk factors for diabetes, heart disease, and cancer. Unlike water fasting, it's safer for most people and easier to sustain.
Many confuse FMD with intermittent fasting or keto fasting diet. While all involve calorie restriction, FMD specifically targets autophagy through nutrient composition. Intermittent fasting focuses on timing, while keto emphasizes fat intake.
To do this at home, follow these steps:
For example, my first attempt included:
I noticed increased mental clarity and reduced hunger after the first 3 days.
Dr. Valter Longo's research at USC shows FMD can regenerate immune cells and improve metabolic health. A 2017 study published in Cell Metabolism found participants lost weight and improved markers of aging after multiple cycles.
Consult a doctor before starting, especially if you have medical conditions. Avoid FMD if pregnant, breastfeeding, or underweight. Some people experience headaches or fatigue initially, but these usually pass within a few days.