Fasting is a practice that has been gaining popularity in recent years, with a growing body of research supporting its benefits. In a previous report, we highlighted various benefits of fasting, such as enhanced body composition, increased energy, improved gut health, strengthened immunity, sharper mental function, healthier heart, extended lifespan, disease prevention, and better self-control. In this article, we'll delve into some of these benefits before discussing the latest research on fasting.
One of the main benefits of fasting is that it can boost fat oxidation and fat-burning, and elevate human growth hormone secretion, which preserves muscle and burns body fat. Energy levels tend to rise during extended fasts due to an increase in adrenaline, an evolutionary mechanism that boosts the body's energy levels during food scarcity. Additionally, fasting regulates ghrelin, the "hunger hormone," and balances out appetite by allowing leptin to normalize, which is responsible for satiety.
Fasting can also protect the gut against stress, increase microbial diversity and fermentation rates, and enhance the immune system. Studies conducted on mouse models of autoimmune diseases have shown that fasting can improve gut health and enhance immune function. Fasting also induces autophagy in neurons, which safeguards nerve cells from degeneration and elevates the secretion of brain-derived neurotrophic factor (BDNF), promoting the growth of new nerve cells and neural pathways for better brain function, particularly memory and learning.
Fasting has also been shown to improve blood lipid markers indicative of heart health, including blood pressure, cholesterol, blood sugar, insulin sensitivity, and triglycerides. Autophagy is accelerated during fasting, which is a repair process that removes damaged proteins and replaces them with new ones, resulting in anti-aging, longevity, and optimal metabolic health. Fasting also enhances self-control and willpower, as it requires a great deal of discipline and conscious resistance to the physical urge to eat, which can translate to other areas of life by boosting self-discipline and the ability to resist temptations and distractions.
There are various fasting methods that have been explored in research, including time-restricted feeding (TRF), intermittent fasting (IF), fasted cardio (FC), calorie restriction (CR), intermittent calorie restriction (ICR), and a very-low-calorie ketogenic diet (VLCKD). TRF involves eating during an 8- to 12-hour daytime window and fasting during the remaining 12 to 16 hours, while IF is an umbrella term that includes various other types of fasting, including TRF and 24-hour fasting. FC involves low-intensity exercise in a fasted state, such as swimming, hiking, or biking. CR involves reducing average daily caloric intake without malnutrition or deprivation of essential nutrients, while ICR involves reducing average daily caloric intake intermittently, such as three days per week, and resuming food consumption as typical on the remaining days. A VLCKD involves eating very few calories to induce ketosis, typically consisting of 600-800 kcal/day, less than 50g carbohydrates, low lipids, and 0.8-1.2 g of protein per kilogram bodyweight.
Different types of fasting may involve different levels of calorie restriction, and research has shown the potential benefits of each type of fasting, including improved body composition, energy levels, appetite regulation, gut health, immune system health, brain health, heart health, longevity, and self-control. In conclusion, fasting is a promising practice that can bring numerous health benefits, and with more research, we can discover even more ways to harness its power.