In this day and age of excessive calorie consumption, sedentary lifestyle and associated obesity, intermittent fasting, IF, seems like a much-needed solution. Stopping food intake for certain periods of time allows the digestive system, brain and other organs to take a break from metabolizing ingested calories. Food digestion, absorption and metabolism, though much needed to survive, are a taxing function on a number of organs. The consumption of rich meals in fat and carbohydrates and the constant snacking on calorie dense, highly processed food items can overrun mitochondrial energy processing. When mitochondria don’t operate efficiently, they generate free radicals that result in oxidative stress. Free radicals are unstable molecules that damage cells, increase inflammation, and shorten survival. Oxidative stress is suspected to play an important role in chronic diseases like atherosclerosis, Alzheimer and Parkinson disease. Studies in rodents have clearly shown increased longevity in association with reduced calorie intake. Whether the same applies to humans or not is still unknown. One thing for sure, our bodies have evolved over thousands of years of hunger and famine. We are efficient at conserving calories, and we are adapted to fast and survive prolonged periods of calorie restriction. “There is nothing else you can do to your body that is as powerful as fasting”, concluded Dr. Michael Mosley, author of The FastDiet book. The benefits of IF in Mosley’s book go beyond simple calorie restriction and weight loss. IF stimulates autophagy; the non-inflammatory process that destroys and eliminates old and damaged cells. IF switches on repair genes that rejuvenates the immune system. The effects of IF are long lasting and result in durable weight loss, improved blood sugar control and decreased cholesterol and blood insulin levels.
Fasting is hard to start and difficult to maintain. There are a number of protocols in the literature you can follow. I prefer to fast along the circadian rhythm. I start by skipping dinner and loading my calories in the morning. I then fast from early afternoon till early morning for a period of 15 to 17 hours. The circadian rhythm is a master clock that regulates the sleep /wake cycle and optimize energy metabolism. During the sleep cycle our body favors fasting with increased lipid catabolism and liver gluconeogenesis. During the wake cycle, insulin synthesis increases promoting glycogen formation and lipogenesis. Feeding during the sleep cycle disrupts the circadian clock and increase oxidative stress. Dr. Mosley advocates the 5:2 diet in his book The FastDiet which entails fasting for two days of the week. Others prefer to skip breakfast and lunch and consume one meal a day around dinner time. This pattern is particularly common for individuals following the keto diet.
In summary, Intermittent Fasting may have a number of health-related benefits. IF is particularly relevant to overweight, and insulin resistant individuals. The majority of adults in Houston are overweight, and with type 2 Diabetes on the rise, IF may be a powerful survival tool.