The fast-mimicking diet offers the benefits of fasting without the need for complete food restriction. Consider consulting a nutritionist or doctor to determine if this is a safe option for you.

Fasting is the practice of abstaining from food for a set period and has been used for millennia for religious, spiritual, and health reasons. Ancient physicians like Hippocrates often prescribed fasting for cleansing and healing.

It’s believed fasting offers many health benefits. It aids in weight loss by reducing calorie intake and improving metabolism. It may also trigger cellular repair, improve insulin sensitivity, and reduce inflammation.

The fast-mimicking diet (FMD), developed by biogerontologist Valter Longo, mimics fasting effects while still allowing small food portions.

How does it work, and what foods are allowed? Let’s explore FMD to uncover its benefits and potential risks.

The FMD is designed to mimic the effects of fasting on the body without actually requiring complete food restriction.

It involves consuming a plant-based diet for a specific period, typically 5 days. This diet also consists of consuming:

  • a low amount of calories, around 700 calories per day
  • low sugars
  • low proteins
  • high in unsaturated fats

Unlike daily or weekly fasting diets, the FMD operates on a monthly cycle.

The idea is to provide the body with enough nutrients to function while still triggering some of the beneficial effects of fasting, such as cellular rejuvenation and metabolic changes.

The FMD is followed for 5 days and has a specific breakdown of macronutrients (protein, fat, and carbohydrates):

  • Day 1: Consume 1,100 calories, with 11% from protein (121 calories from protein), 46% from fat (506 calories from fat), and 43% from carbohydrates (473 calories from carbohydrates).
  • Days 2 to 5: Consume only 725 calories per day, with a breakdown of 9% protein (65 calories from protein), 44% fat (319 calories from fat), and 47% carbohydrates (341 calories from carbohydrates).

Here’s an example of foods you can eat on the FMD:

  • Healthy fats: olive oil, avocados, nuts, seeds
  • Plant-based protein sources: legumes, lentils, beans
  • Fruits: berries, apples, oranges, other nonstarchy fruits
  • Whole grains: brown rice, quinoa, oats, whole wheat products
  • Noncaffeinated herbal teas: chamomile, peppermint, hibiscus
  • Vegetables: leafy greens, cruciferous vegetables, tomatoes, carrots, peppers

It’s also important to drink at least 70 ounces of water each day.

FMD has been researched in both mice and a small sample size of humans with promising results. In mice, this diet has been shown to:

  • protect healthy cells
  • eliminate damaged cells (including cancerous ones)
  • reduce inflammation
  • enhance overall health

Similarly, in humans, the FMD was associated with:

Fasting-like diets have also shown promise in activating protective processes in cells, which could be beneficial for preventing or treating Alzheimer’s disease. Both animal and human studies have shown benefits for memory and overall well-being, but further research is needed to support these findings.

How often should you do the FMD diet?

The FMD is typically followed for 5 consecutive days, once a month, for 3 months.

If you’ve reached your goals in 3 months, you can stop or adjust the FMD. If you’re using it for long-term health or to manage a condition, you can continue with changes as needed based on your progress and health.

Here are some potential benefits of a fasting-mimicking diet based on research:

  • Weight loss: FMD can lead to reductions in body weight and body fat.
  • Improved metabolic health: FMD may improve markers of metabolic health, such as blood pressure, fasting glucose levels, and insulin sensitivity.
  • Reduced inflammation: FMD has been shown to reduce levels of inflammatory markers like C-reactive protein (CRP).
  • Lowered risk factors for age-related diseases: FMD may decrease risk factors for diseases associated with aging, such as cardiovascular disease and diabetes.
  • Cellular rejuvenation: FMD can activate cellular stress response pathways and autophagy, which may promote cellular repair and rejuvenation.
  • Improved cognitive function: FMD may improve cognitive function, which could be beneficial for brain health and Alzheimer’s disease prevention.

The FMD is generally considered safe for healthy individuals when followed as instructed. Here are a few of the more well-known side effects:

  • Hunger and discomfort: The low-calorie nature of the diet may lead to increased hunger, which can be uncomfortable.
  • Fatigue and weakness: Some people may experience fatigue or weakness due to the reduced calorie intake.
  • Potential for disordered eating: Following a restrictive diet like the FMD could potentially exacerbate unhealthy or disordered eating patterns in people with eating disorders.
  • Adverse effects on certain medical conditions: People with certain medical conditions, such as diabetes, may experience negative effects on blood sugar levels.

In a study of 100 generally healthy participants trying the FMD, 54% to 100% reported no adverse effects during the FMD cycles.

The most common self-reported symptoms were mild to moderate fatigue, weakness, and headaches. No severe adverse effects were reported. Overall, after three cycles of the FMD, participants reported only mild to moderate side effects.

Overall, the diet resulted in reductions in:

  • body weight
  • body fat
  • blood pressure
  • insulin-like growth factor 1 (IGF-1)

The FMD was found to be safe, feasible, and beneficial for participants at risk for disease, with improvements in various health markers.

The FMD offers a unique approach to improving health by mimicking the effects of fasting while still providing essential nutrients. Though more robust research is warranted, it’s shown potential benefits such as:

  • weight loss
  • reduced inflammation
  • enhanced insulin sensitivity

When done correctly and under supervision, the FMD could be a valuable tool for enhancing overall health and well-being.