What can I eat on a mimicking fast diet? A Complete Food Guide

Studies from the University of Southern California indicate that a fasting-mimicking diet can improve metabolic markers like blood sugar, cholesterol, and blood pressure. But what can I eat on a mimicking fast diet that is primarily plant-based, low-calorie, and specifically formulated to induce these fasting-like effects while still consuming food?

Quick Summary

This guide details the specific plant-based foods, healthy fats, and low-protein options allowed during a fasting-mimicking diet to trigger the body's regenerative processes while managing hunger.

Key Points

• Plant-Based Focus: The core of an FMD is a plant-based, low-calorie, and low-protein diet to mimic fasting effects while still providing nutrients.

• High in Healthy Fats: Healthy fats from sources like olive oil, nuts, avocados, and olives are vital for satiety and energy during the caloric restriction.

• Avoid Animal Products and Sugar: All animal protein, dairy, refined sugars, and processed foods must be avoided to maintain the fasting state.

• Soups are Key: Low-sodium vegetable and lentil soups are central to the meal plan, providing hydration and feeling substantial.

• DIY vs. Kit: DIY requires meticulous calorie and macro tracking, while a pre-packaged kit (like ProLon) offers convenience and precise formulation.

• Consult a Doctor: It is critical to speak with a healthcare provider before starting an FMD, especially with pre-existing health conditions.

Understanding the Fasting-Mimicking Diet (FMD)

The fasting-mimicking diet (FMD) is a specific dietary regimen, typically followed for five consecutive days each month, that was developed to produce the health benefits of traditional fasting without complete food restriction. The diet is plant-based, low in calories, protein, and carbohydrates, but higher in healthy fats. This unique macronutrient ratio and calorie restriction are designed to keep the body in a pseudo-fasting state, triggering beneficial cellular processes like autophagy, where the body cleans out damaged cells. It's a cyclical approach, meaning after the five days, you return to your normal, healthy diet until the next cycle.

The Macronutrient Blueprint

The FMD is not a 'free-for-all' diet of simply eating low-calorie plant foods. The precise macronutrient ratios are key to tricking the body into a fasting state.

• Day 1: Higher caloric intake, roughly 1090 kcal, with a breakdown of approximately 10% protein, 56% fat, and 34% carbohydrates.
• Days 2-5: Lower caloric intake, around 725 kcal, with a macronutrient ratio of approximately 9% protein, 44% fat, and 47% carbohydrates.

Approved Foods for Your FMD

Sticking to a whole-food, plant-based approach is crucial. Here are the categories of foods that form the foundation of a successful FMD cycle.

Vegetables

Focus on non-starchy vegetables that are high in fiber and nutrients while being low in carbohydrates. These can be eaten in soups, salads, or steamed.

• Leafy Greens: Spinach, kale, romaine lettuce, and arugula are excellent choices.
• Cruciferous Vegetables: Broccoli, cauliflower, cabbage, and bok choy are staples.
• Other Vegetables: Zucchini, celery, cucumbers, bell peppers, mushrooms, and tomatoes.

Healthy Fats

Healthy fats are essential for providing satiety and energy on a low-calorie diet. They also support the specific macronutrient ratios required for FMD.

• Oils: Olive oil is a primary source of healthy fat.
• Nuts and Seeds: Almonds, walnuts, macadamia nuts, pecans, chia seeds, flaxseeds, and pumpkin seeds are great for small, measured snacks.
• Fruits: Avocados and olives are excellent sources of healthy fats.

Plant-Based Protein

Protein is kept very low on the FMD, but small amounts are included from plant-based sources.

• Legumes: Lentils, chickpeas, and beans can be used in limited quantities, often in soups.
• Soy Products: Limited amounts of tofu or tempeh are sometimes included, particularly in DIY meal plans.

Whole Grains

Carbohydrates are limited, but small servings of specific whole grains can be included, especially in early FMD meals.

• Quinoa: A good source of protein and fiber, used sparingly.
• Brown Rice: In small portions for variety.

Low-Sugar Fruits

Some low-glycemic fruits are permitted in small amounts for a touch of sweetness and antioxidants.

• Berries: Raspberries, blueberries, and strawberries are common choices.
• Other Fruits: Small portions of apples or oranges.

Soups and Broths

Soups and broths are foundational, providing hydration and warmth while feeling substantial. Use low-sodium vegetable broths as a base.

Beverages

Staying hydrated is vital. Stick to non-caloric and non-sweetened options.

• Water: The most important fluid.
• Herbal Tea: Chamomile, hibiscus, and green tea are good options.
• Coffee: Plain, black, decaf coffee is often allowed in limited amounts, but some FMD kits (like ProLon) specify limits on caffeine.

Foods to Strictly Avoid

To ensure the fasting state is maintained, it is critical to avoid certain food categories entirely. This includes all animal products, most starches, processed foods, and sugar.

Sample FMD 5-Day Meal Plan

This is a simplified example based on common FMD principles. Note: Exact quantities and calorie counts should be carefully managed, especially for DIY.

• Day 1:
  • Breakfast: Herbal tea with a small handful of almonds.
  • Lunch: A cup of lentil soup with a few olives.
  • Dinner: Steamed broccoli and zucchini with a tablespoon of olive oil.
• Day 2:
  • Breakfast: Herbal tea and a small apple.
  • Lunch: Vegetable broth with finely diced celery and carrots.
  • Snack: Celery sticks with a small portion of hummus.
  • Dinner: A cup of low-salt, broth-based lentil soup.
• Day 3:
  • Breakfast: Herbal tea and a small handful of pecans.
  • Lunch: A small serving of cooked quinoa with steamed green beans.
  • Snack: A small orange.
  • Dinner: Leafy green salad with mushrooms and bell peppers, dressed with olive oil and lemon juice.
• Day 4:
  • Breakfast: Herbal tea and a small serving of berries.
  • Lunch: Clear vegetable broth with diced carrots and tomatoes.
  • Snack: Cucumber slices with a small handful of almonds.
  • Dinner: Stir-fried vegetables (cabbage, kale) with a small portion of firm tofu.
• Day 5:
  • Breakfast: Herbal tea and a small handful of walnuts.
  • Lunch: A cup of black bean soup.
  • Snack: Olives.
  • Dinner: Steamed asparagus with olive oil.

DIY vs. Pre-packaged FMD Kits

Feature	DIY Fasting-Mimicking Diet	Pre-packaged FMD Kit (e.g., ProLon)
Cost	Generally cheaper.	More expensive, as it includes pre-measured and formulated meals.
Convenience	Requires significant planning, meal prep, and tracking.	Highly convenient; all meals are pre-packaged and portion-controlled.
Accuracy	Higher risk of incorrect calorie and macronutrient ratios. Requires meticulous tracking.	Formulated based on extensive research to be precise and effective.
Flexibility	Full control over food choices and flavor profiles.	Limited to the items provided in the kit.
Safety	Requires more diligence to ensure nutritional needs are met without breaking the fast. Higher risk of mistakes.	Clinically tested and safer, assuming no pre-existing health conditions.

Important Considerations Before Starting

Before undertaking an FMD, whether DIY or pre-packaged, it's crucial to consult a healthcare provider. The diet is not suitable for everyone, including those who are pregnant or breastfeeding, people with a history of eating disorders, and individuals with underlying medical conditions like diabetes, kidney disease, or heart disease. A doctor can help determine if FMD is appropriate for you and provide personalized guidance.

Conclusion

Successfully navigating a mimicking fast diet depends on carefully selecting low-calorie, plant-based foods that meet specific macronutrient criteria. By focusing on vegetables, healthy fats, limited plant proteins, and low-sugar fruits while avoiding animal products and processed foods, you can induce the body's fasting-like state and trigger cellular regeneration. While a pre-packaged kit offers accuracy and convenience, a DIY approach is possible with meticulous planning and tracking. Always remember to prioritize safety by consulting a healthcare professional before beginning any new dietary regimen, especially one that significantly restricts calories.

For more detailed research on the benefits of FMD and its development, refer to studies led by Dr. Valter Longo and the USC Longevity Institute(https://valterlongo.com/fasting-mimicking-program-and-longevity/).

Frequently Asked Questions

What kind of soups can I eat on a mimicking fast diet?

You can eat low-sodium vegetable broths and soups made from approved plant-based ingredients like lentils, tomatoes, mushrooms, spinach, and other non-starchy vegetables. The key is to keep them low in calories and protein.

Is coffee or tea allowed during the mimicking fast diet?

Herbal teas like chamomile or green tea are generally allowed and encouraged for hydration. Some FMD programs permit a small amount of plain, black decaffeinated coffee, but check the specific guidelines of your plan.

Can I have fruit on a mimicking fast diet?

Yes, but in limited amounts and focusing on low-sugar varieties. Berries, apples, and oranges are typically approved, but they should be consumed in moderation as a small snack.

How many calories do you eat on an FMD?

On the first day, the caloric intake is higher (around 1090 kcal), and it drops to a lower level (around 725 kcal) for the remaining four days of the 5-day cycle.

Is a DIY mimicking fast diet safe?

A DIY FMD is possible but carries a higher risk of error in calorie and macronutrient ratios, which could undermine the diet's purpose or lead to nutrient deficiencies. A pre-packaged kit like ProLon is scientifically formulated for precision. It is always best to consult a healthcare provider.

What foods should I avoid on the FMD?

You must avoid all animal products (meat, dairy, fish), high-starch foods (white rice, potatoes), processed foods, refined sugars, and sugary beverages. Essentially, anything not on the approved plant-based list is off-limits.

How long does a mimicking fast diet last?

A standard mimicking fast diet cycle lasts for five consecutive days. It is a periodic regimen, often recommended to be repeated monthly or every few months.

Does the FMD help with weight loss?

Yes, studies have documented weight loss and reduced belly fat as benefits of the FMD. However, the diet is not solely for weight loss but for broader metabolic health improvements.