Fasting Mimicking Diet (FMD) originally developed by Dr. Valter Longo is a 5-day structured, low-calorie, plant-based meal protocol. It tricks the body into entering a fasting state (inducing cellular autophagy, lowering blood glucose, and decreasing IGF-1) while still providing enough nutrients and calories to remain safe and mitigate severe hunger.

The basic structure

• Day 1: about 1,100 calories, or roughly 55% of your usual intake
• Days 2-5: about 700-800 calories, or roughly 35-40% of your usual intake

Macros: low protein (about 10%), low carbohydrate (about 40-45%), and high in healthy fats (about 45-50%)

Frequency: typically once a month for 3 months, then once every 3 months for maintenance

Comprising...

• Vegetable soups (minestrone-style, tomato, mushroom, or similar)
• Small amounts of nuts, olives, and olive oil for fat
• Herbal teas, plus water throughout the day
• Minimal sugar and refined carbs
• No animal protein, dairy, or alcohol
• Little to no caffeine, though some versions allow small amounts of coffee or tea

Fasting Mimicking Diet: DIY 5-Day Meal Plan

This plan follows the structure of Valter Longo's fasting mimicking diet. Calorie numbers are approximate and it won't match the exact formulation of the commercial Prolon kit, so use a food tracker for the first day or two to stay near the targets.

Day 1 (~1,100 kcal)

• Breakfast: Herbal tea and 1 bowl (about 1.5 cups) of vegetable soup with 1 tsp olive oil (~200 kcal)
• Snack: 20 g walnuts or almonds (~120 kcal)
• Lunch: 2 cups vegetable soup with 1 tbsp olive oil, plus 6-8 olives (~350 kcal)
• Snack: Raw veggies (celery, cucumber, peppers) with 1 tbsp tahini or a few olives (~100 kcal)
• Dinner: 2 cups soup, ½ cup cooked brown rice or quinoa, and a side of steamed greens with 1 tsp olive oil (~330 kcal)

Days 2-5 (~700-800 kcal each)

• Morning: Herbal tea and 1.5 cups vegetable soup with 1 tsp olive oil (~170 kcal)
• Midday: 2 cups vegetable soup with 1 tbsp olive oil (~250 kcal)
• Snack: 20-25 g nuts (walnuts, almonds, or macadamias) plus 4-5 olives (~170 kcal)
• Evening: 1.5 cups soup, steamed or sautéed greens, and 1 tsp olive oil (~180 kcal)
• Throughout the day: Water, herbal tea, and a little black coffee if you need it

Rotate the soup flavors (tomato, mushroom, minestrone, leek and potato) so it doesn't get monotonous.

Base Soup Recipe

Makes about 6 cups, ~100-120 kcal per cup before added oil.

• 1 onion
• 2 carrots
• 2 celery stalks
• 2 zucchini
• 1 cup chopped tomatoes
• 2 cups greens (kale, spinach, or chard)
• 1 small potato
• 2 garlic cloves

Simmer everything in 6 cups of water or low-sodium vegetable broth for 30 minutes, then season with salt, pepper, herbs, and a squeeze of lemon.

Day 6 (Refeeding)

Go gently with small portions: broth, soup, and cooked vegetables, then add whole grains and legumes in the evening. Wait until day 7 to resume your normal diet, including animal protein.

Tips

• Salt your soup a bit more than usual to help prevent lightheadedness, and sip fluids all day.
• Keep activity light, with walking and stretching only.
• Stop and eat normally if you feel dizzy, faint, or unwell.