Fasting is often misunderstood, with many believing it slows down metabolism and leads to fatigue. However, Dr. Jason Fung, a leading advocate of intermittent fasting, reveals that the opposite may be true. In his discussion on the Diary of a CEO podcast, Dr. Fung explains how fasting impacts your body, challenging common assumptions about food and energy levels.
Fasting Increases Energy, Not Fatigue
Contrary to popular belief, fasting doesn’t slow down your metabolism. Dr. Fung explains that when you stop eating, your body starts to burn stored calories for energy. This process actually increases your metabolic rate rather than decreasing it. “Your insulin levels drop, and other hormones like growth hormone and cortisol increase, which actually boosts your energy levels,” says Dr. Fung. This goes against the common notion that fasting may make you sluggish. Instead, your body becomes more efficient at utilizing stored energy, leading to increased vitality and alertness.
The Fight-or-Flight Response During Fasting
During fasting, the body enters a heightened state of alertness, often referred to as the fight-or-flight response. According to Dr. Fung, “Hungry animals are more dangerous because their bodies are in a state of activation, ready to find food.” This physiological response is driven by increased levels of cortisol and growth hormone, which enhance your body’s ability to use stored energy efficiently. This heightened state can improve focus and physical performance, contradicting the idea that fasting leaves you feeling weak and tired.
Health Benefits Beyond Weight Loss
Fasting isn’t just about losing weight; it offers a range of health benefits that extend beyond the scale. Research from Cambridge University supports the idea that fasting can reduce harmful inflammation in the body by increasing levels of a key fatty acid called arachidonic acid. This reduction in inflammation has potential implications for lowering the risk of chronic diseases such as Alzheimer’s and Parkinson’s. “Our work adds to the growing evidence that calorie restriction has broad health benefits,” says Professor Clare Bryant of the University of Cambridge. By lowering inflammation, fasting may help protect against a variety of age-related diseases, contributing to overall longevity and well-being.
Fasting and Brain Health
The benefits of fasting extend to brain health as well. By reducing inflammation and boosting arachidonic acid levels, fasting might help protect against neurodegenerative diseases like Alzheimer’s and Parkinson’s. While more research is needed to fully understand these long-term effects, the emerging science suggests that fasting could be a simple yet effective way to support cognitive health as you age. Regular fasting may enhance brain function, improve memory, and even reduce the risk of mental decline.
The Breakfast Debate: To Eat or Not to Eat?
While Dr. Fung advocates for fasting, particularly intermittent fasting, not all experts agree on the benefits of skipping breakfast. Nutrition therapist Justin Nault warns that not eating in the morning could signal underlying metabolic issues. He argues that breakfast helps kickstart your metabolism and prevent unhealthy metabolic adaptations. The NHS also advises against skipping breakfast, citing its importance for overall health. The debate highlights the importance of understanding your body’s needs and how different dietary practices may affect you personally.
Should You Try Fasting?
If you’re considering trying fasting, it’s essential to consult with your doctor first. While fasting can offer numerous health benefits, it’s not suitable for everyone. Some individuals, particularly those with certain medical conditions or dietary needs, may find fasting challenging or even harmful. “Don’t just change your lifestyle because someone on the internet said so,” advises Dr. Fung. Understanding the science behind fasting and how it affects your body can help you make an informed decision about whether it’s the right approach for you.
Conclusion: Rethinking Fasting and Its Impact on Your Body
Fasting, when done correctly, can have a range of surprising benefits that challenge the conventional wisdom about food and energy. From increasing your metabolic rate and energy levels to offering protection against chronic diseases and supporting brain health, fasting is more than just a diet trend—it’s a powerful tool for overall well-being. However, like any health practice, it’s crucial to approach fasting with knowledge and care. By consulting with healthcare professionals and listening to your body, you can determine if fasting is a suitable and beneficial addition to your lifestyle.
