Fasting Mimicking Diet (FMD)

What You Need to Know About L-Nutra’s ProLon® Program

Intermittent fasting and prolonged fasting have gained significant attention for their potential benefits in metabolic health, inflammation, and longevity. However, fasting is not feasible—or safe—for everyone. This is where the Fasting Mimicking Diet (FMD), developed by L-Nutra, offers an alternative approach that aims to deliver many of the benefits of fasting while still providing essential nutrients.

The Fasting Mimicking Diet is a 5-day, plant-based, calorie-restricted nutrition program designed to place the body into a fasting-like metabolic state without complete food abstinence. Developed by Dr. Valter Longo and his research team at USC, the FMD is backed by decades of laboratory and clinical research. L-Nutra’s commercial version of the FMD is known as ProLon®, which provides pre-packaged meals formulated to precisely control calories, macronutrients, and micronutrients over five consecutive days.

During the FMD, caloric intake is significantly reduced—typically to about:
Day 1: ~1,100 calories
Days 2–5: ~700–800 calories per day.

Protein intake is kept very low, carbohydrates are complex and plant-based, and fats are primarily unsaturated. This specific composition is designed to:

• Lower insulin and IGF-1 levels
• Promote fat burning and ketone production
• Activate cellular stress-resistance pathways
• Stimulate autophagy and cellular renewal.

In essence, the body “believes” it is fasting, even though it continues to receive targeted nutrition.

Clinical studies suggest that periodic use of the Fasting Mimicking Diet may offer a range of health benefits, including:

• Improved metabolic markers (glucose, insulin sensitivity, cholesterol)
• Reduced inflammation
• Decreased abdominal fat
• Support for cellular repair and regeneration
• Potential longevity benefits

Some research has also explored FMD’s role in supporting patients with cardiometabolic risk factors and in adjunctive settings under medical supervision.

The FMD may be a useful option for individuals who:

• Are interested in the benefits of fasting but cannot tolerate prolonged fasting
• Have insulin resistance or metabolic syndrome
• Want a structured, time-limited nutritional reset
• Prefer a clinically studied and standardized program.

That said, this is not a one-size-fits-all intervention.
The Fasting Mimicking Diet is not appropriate for everyone. It should be avoided by individuals who:

• Are pregnant or breastfeeding
  
• Have a history of eating disorders
  
• Are underweight
• Have insulin-dependent diabetes or labile blood sugars
• Have advanced kidney disease or electrolyte abnormalities 
• Are taking certain medications 

As with any therapeutic dietary intervention, individualized assessment is essential.

From a Lifestyle Medicine perspective, the Fasting Mimicking Diet should be viewed as a tool, not a replacement for foundational lifestyle practices.

When used appropriately, the FMD can serve as a metabolic “reset” or jumpstart, but sustainable lifestyle changes remain the cornerstone of health and disease prevention.

The Fasting Mimicking Diet by L-Nutra represents an innovative, research-based approach to harnessing the benefits of fasting while maintaining nutritional intake. For selected individuals, it may offer meaningful metabolic and cellular benefits when integrated thoughtfully into a comprehensive lifestyle medicine plan. As always, anyone considering the FMD should do so in partnership with a knowledgeable healthcare professional to ensure safety and appropriateness.