Intermittent fasting is the new buzz in the weight loss world. Beyond that, this strategy also shows promise in reducing risks for chronic lifestyle diseases. However, what we need to know is what intermittent fasting is, how it works, and is there solid science to back it up? Or is it just a fad?
Intermittent fasting describes a pattern of eating within a certain window of time each day and fasting the rest. The idea takes into consideration the body’s natural cycles and circadian rhythms. There are three types of intermittent fasting, including modified/5:2, alternate-day fasting, and time-restricted fasting, which is currently the most known. An example of time-restricted fasting would be the 16:8 approach, which is very popular. In this strategy, a person would only consume food within an eight-hour window, leaving the body to fast for the other 16.
Time-restricted fasting limits the person’s “eating window” to 4–12 hours, having a daily fasting period of 12–20 hours. Individuals eat to satiety during their eating windows with no real restrictions. There is a growing body of research which suggests that eating for lengthy periods in the day, ranging from 12–15 hours, may disrupt the circadian rhythm and increase the risk of chronic diseases, including heart disease, cancer, and type-2 diabetes. Time-restricted fasting reverses this habit, limiting food to 4-12 hours a day.
Benefits of intermittent fasting include improved cholesterol levels, changed body composition, and blood sugar control. Some researchers believe that intermittent fasting may also have positive effects on neurodegenerative disorders such as Parkinson’s and overall longevity. With all of these benefits, does intermittent fasting have the science to back it up?
The answer is not really. Most of what we know about intermittent fasting is anecdotal and from low-quality research on humans. The most information we have is from animal studies, such as the research on cholesterol. A 2021 review found that only six of 104 alleged health benefits of intermittent fasting were supported by moderate- to high-quality evidence, the rest being lower-quality research.
In the end, the side effects of intermittent fasting are minimal and mostly what we’d call “hangry with a side of fatigue.” It does, however, make sense to give our bodies a break and let our systems reset, let our liver glycogen stores get depleted, and not tax those vital systems with constant eating, especially at night. What do you think? Are you likely to try intermittent fasting?