The joys of fasting
For the past year, fasting has been a cornerstone of my daily life. I’ve embraced intermittent fasting and once a week I undertake a 24-hour fast. This practice has been both a journey of physical health and a mental challenge—a deliberate “hard thing” I do to push myself beyond my comfort zone.
The Health Benefits
Fasting offers a host of physiological advantages, including:
Autophagy: Fasting triggers autophagy, the body’s natural process of cleaning out damaged cells and regenerating healthier ones. This cellular recycling process begins around 16-18 hours into a fast and peaks around 36-48 hours, reducing the risk of neurodegenerative diseases like Alzheimer’s and Parkinson’s by clearing protein aggregates and other cellular debris.
Hormesis: By putting the body under mild stress, fasting strengthens its resilience. Hormesis activates protective pathways such as increased antioxidant production and DNA repair mechanisms, which help the body adapt to various stressors. Hormesis begins to take effect during the metabolic switch around 12-16 hours, amplifying as the body adapts to fasting.
Triglyceride Reduction: Fasting improves lipid profiles by reducing triglycerides and LDL cholesterol levels while increasing HDL ("good") cholesterol. A study published in Cell Metabolism highlights how fasting can enhance lipid metabolism and lower the risk of cardiovascular disease.
Insulin Sensitivity: Extended fasting normalizes insulin levels and improves sensitivity, reducing the risk of type 2 diabetes. According to a study in The Lancet Diabetes & Endocrinology, intermittent fasting can significantly lower fasting insulin levels and improve blood glucose regulation.
Inflammation Reduction: Chronic inflammation—a contributor to diseases like cancer, diabetes, and cardiovascular disorders—is significantly reduced through fasting. Fasting decreases pro-inflammatory cytokines such as IL-6 and TNF-α, while increasing anti-inflammatory markers like adiponectin.
Hormonal Balance: Extended fasts (24+ hours) trigger a surge in growth hormones, which are vital for muscle repair, fat metabolism, and overall health. Studies show that fasting can increase growth hormone levels by up to 2000% in men and 1300% in women.
Gut Health: Fasting allows the digestive system to rest, promoting gut repair and the balance of the microbiome. Research published in Nature Communications indicates that fasting can enhance the diversity of gut bacteria, which is crucial for immune function and overall health.
Longevity: By reducing oxidative stress and enhancing mitochondrial function, fasting may extend lifespan. Animal studies have shown that calorie restriction and fasting can increase lifespan by 30-50%, with similar mechanisms believed to apply to humans.
What Happens When You Fast
Fasting is not just about what you give up; it’s about what your body gains during the process. Here’s a timeline of what happens during a prolonged fast:
12 Hours: The body switches from burning glycogen (stored carbohydrates) to body fat for energy. This metabolic switch is a key driver of fat loss and initiates hormetic processes.
18 Hours: You enter full fat-burning mode, where your body is efficiently utilizing fat stores for energy.
24 Hours: Growth hormone levels surge, aiding in cellular repair, fat metabolism, and muscle maintenance.
36 Hours: Autophagy reaches its peak, and your body dives deep into repairing damaged cells and removing toxins.
48 Hours: Inflammation markers significantly decrease, and the immune system begins to regenerate by producing new white blood cells. Ketone production intensifies, providing an efficient energy source for the brain and muscles.
72 Hours: The immune system undergoes a full reset as stem cell production accelerates, contributing to regeneration and repair.
The Mental Challenge
Beyond the physical benefits, fasting has become a practice of mental resilience for me. Every time I commit to fasting beyond my regular 16 hours I step away from what is familiar and into unknown, often uncomfortable, territory. It’s tough, but fasting is a helpful reminder that growth often comes from facing adversity head-on, whether that’s hunger or any other obstacle in life.
Why I Keep Going
Fasting has become more than a habit; it feels like a way of aligning with myself. The discipline of it, the clarity I feel, and the sense of renewal are things I look forward to. Even on days when fasting feels hard, I remind myself that discomfort is temporary, but the benefits are lasting. It’s not for everyone, but for me, it’s a practice I’ve found enjoyed so far.
If you’ve ever considered fasting, I encourage you to give it a try. Start small, learn how your body responds, and embrace the journey. You might find, as I have, that it’s about much more than just food—it’s about freedom, growth, and living with intention.
