mTOR and fasting

Definition

mTOR (mechanistic target of rapamycin) is a protein kinase that regulates cell growth and protein synthesis, strongly inhibited during fasting to favor autophagy.

How it works

mTOR is a major nutritional sensor that detects the presence of amino acids, glucose, and growth factors to orchestrate protein synthesis and cell growth. In the presence of food, mTOR is activated and promotes anabolism (muscle building) but inhibits autophagy. Conversely, during fasting, the decrease in amino acids and glucose inactivates mTOR, allowing autophagy to be fully activated.

Role

Central regulator determining whether the cell prefers growth (active mTOR) or cellular renewal via autophagy (inhibited mTOR).

Examples

• Activation of mTOR after a protein-rich meal
• Progressive inhibition of mTOR during a 24-hour fast
• Role of mTOR in post-exercise muscle growth
• Chronic overactivation of mTOR implicated in cancer and accelerated aging

Recommendations

Alternate between periods of protein-rich feeding (activating mTOR) and fasting (inhibiting mTOR) for optimal balance · Practice regular intermittent fasting to maintain normal mTOR regulation · Associate fasting with resistance training during feeding to maintain lean mass.

Key takeaway

The balance between mTOR activation and inhibition by fasting and feeding optimizes cellular health and longevity.

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