Myosteatosis: Why fat in your muscles causes diabetes

Insulin resistance isn't just the result of eating too many carbohydrates. There's a hidden factor that few people know about: myosteatosis, or fat infiltrated into muscle, which can be both cause and consequence of metabolic problems.

What is myosteatosis and how does it affect your metabolism?

Myosteatosis is the accumulation of fat within muscle tissue, similar to the marbling you see in wagyu beef. This condition goes beyond the visceral fat we know about and represents a silent threat to your metabolic health.

Factors contributing to myosteatosis:

• Prolonged physical inactivity
• Excess saturated fat consumption
• Frequent intake of refined carbohydrates
• Constant hypercaloric consumption
• Combination of saturated fats and refined carbohydrates

An innovative study published in 2024 in Nature Communications revealed that people with type 2 diabetes or insulin resistance had significant amounts of polyunsaturated fats stored within muscle tissue, with lower muscle density and greater fat infiltration.

The connection between muscle fat and insulin resistance

When fat infiltrates muscle, it profoundly alters this tissue's ability to metabolize fuel efficiently. Muscles are the body's energy powerhouses where mitochondria manufacture energy.

Effects of myosteatosis on your body:

1. Disrupts lipid kinetics: The ability to oxidize fats is compromised
2. Reduces mitochondrial function: Fewer sites for energy production
3. Increases inflammation: Elevating insulin resistance
4. Increases type 2 diabetes risk by 34%
5. Elevates high triglyceride risk by 40%

Research in Arteriosclerosis, Thrombosis, and Vascular Biology confirmed these alarming findings, while another study in Medicine & Science in Sports & Exercise demonstrated that lower intramuscular fat correlates with lower inflammation.

Scientific strategies to eliminate muscle fat

The good news is that myosteatosis is reversible. Here are the most effective evidence-based strategies:

Resistance training

Resistance exercise is the most powerful tool to combat myosteatosis. It works like a warehouse with multiple ovens:

• Increases PGC1A: Promotes mitochondrial biogenesis
• Improves muscle density: More sites to burn fat
• Increases mitochondria: From 4 ovens to 30 ovens in your muscle "warehouse"
• Facilitates intramuscular fat oxidation: The first to burn during exercise

Creatine supplementation

Creatine is one of the most studied supplements after caffeine, with proven benefits for:

• Increasing ATP production
• Improving energy utilization
• Building quality muscle mass
• Benefiting brain function (especially useful when sleep deprived)

Recommended dose: 1.5-3 grams distributed throughout the day to minimize water retention.

TMG (trimethylglycine)

This compound has been shown to increase fatty acid oxidation, which is crucial because:

• Intramuscular fats burn first during exercise
• Improves metabolic efficiency during physical activity
• Facilitates mobilization of stored fats in muscle

Increased protein intake

A clinical study with 193 participants demonstrated that a high-protein diet significantly improved muscle density and reduced intramuscular fat.

Protein mechanisms:

1. Thermogenic effect: Burns calories during digestion
2. Muscle protein synthesis: Builds lean tissue
3. Stimulates glucagon: Hormone that promotes fat oxidation
4. Provides leucine: Amino acid that stimulates mitochondrial biogenesis

The vicious cycle of myosteatosis

It's important to understand that myosteatosis can be both cause and consequence of insulin resistance, creating a cycle that progressively worsens:

Inactivity → Muscle fat accumulation → Insulin resistance → Greater metabolic dysfunction → More muscle fat

The key is breaking this cycle through:

• Regular movement and resistance exercise
• Reduction of hypercaloric intake
• Limitation of saturated fats and refined carbohydrates combined
• Implementation of mentioned nutritional strategies

Myosteatosis represents a critical but little-known factor in metabolic health. By understanding how fat infiltrated into muscle affects your ability to use energy efficiently, you can take proactive measures to reverse this condition and significantly improve your long-term metabolic health.