There will be many Kingos going on a diet to prepare for the upcoming summer vacation. Intermittent fasting, which was first introduced to Korea a few years ago, became a hot dietary trend again as it was introduced as a diet method by many celebrities. Accordingly, the Sungkyun Times (SKT) will introduce the principle, effects, and precautions of intermittent fasting.
What Is Intermittent Fasting?
Intermittent fasting is an eating pattern where a person cycles between periods of fasting and eating at regular intervals. After glucose has initially been completely consumed as an energy source, the accumulated fat starts to break down and is used as energy. It applies to the length of the fasting time that maximizes fat loss while enabling a daily routine. It was first popularized by British Broadcasting Corporation (BBC) journalist Dr. Michael Mosley’s book The Fast Diet. In Korea, the Seoul Broadcasting System (SBS) documentary special Rebellion of the Meal firstly introduced intermittent fasting in 2013, and 2019 Rebellion of the Meal reintroduced it in January 2019. With much scientific evidence showing that intermittent fasting is effective both for losing weight and improving health, it is now becoming a new lifestyle for many modern people. Though there are many variations of intermittent fasting methods, the following two are the most common.
➊ 16:8 Diet
This method consists of sixteen hours of partial fasting and eight hours of eating each day.
➋ 5:2 Diet
This is a method of two days of partial fasting and five days of normal eating on a weekly basis. Since the effects of those two methods may differ depending on each individual’s body condition, it is recommended to flexibly adjust the fasting time to fit each person’s life pattern. Due to the flexibility of the fasting time, intermittent fasting is regarded as an easy and sustainable way to lose weight.
The Positive Effects of Intermittent Fasting
➊ Losing Weight
Losing weight is the biggest reason for the popularity of intermittent fasting. Intermittent Fasting does not restrict calorie intake but changes the way of consuming fat and glucose. For example, the fasting state prevents the accumulation of fat by consuming them as an energy source instead of glucose. Besides this, intermittent fasting also converts white fat, which makes people gain weight by saving surplus energy, into brown fat which consumes calories while producing heat. Indeed, the University of Illinois in the United States (US) announced in 2018 that maintaining intermittent fasting for three months would reduce the average weight of a person by approximately 3%.
➋ Detoxing Effect and Prevention of Diseases
Some might assume that intermittent fasting only has the effect of losing weight, but it also has the effect of preventing diseases by cleansing the body. When a person’s body is in extremely stressful conditions such as nutritional starvation, the body starts to activate autophagy to protect itself. Autophagy is the body’s critical mechanism of maintaining proper cell function by destroying all the useless cells. Many studies including vitro and vivo animal studies discovered that autophagy can help prevent various diseases including cancer. Since cancer cells grow in highly nourishing environments, autophagy activated by intermittent fasting can prevent cancer. It can also improve brain function. The process of burning fat in intermittent fasting releases chemicals called ketones which help strengthen neural connections in the brain’s learning and memory areas. It can prevent brain diseases such as Alzheimer’s and Parkinson’s diseases. Some researches showed that a boost in ketone production can improve the memory of elderly people with early signs of dementia in only six weeks.
Concerns and Precautions Regarding Intermittent Fasting
Concerns Regarding Intermittent Fasting
Fasting for long hours can trigger subsequent overeating because of the increased stress levels and thus increase the risk of obesity. Once the body recognizes the energy depletion as an emergency, it breaks down the protein first to use it as an energy source. This results in the reduction of the body’s muscle mass and basal metabolic rate, which can eventually make people gain weight more easily. Besides this, muscle loss can lead to side effects such as dizziness and hair loss, as well as serious illnesses like diabetes and hyperlipidemia which can cause heart disease. Most of all, since the long-term effects of intermittent fasting have not yet been extensively studied, it is uncertain whether there are any dangers in the long run.
Precautions of Intermittent Fasting
To prevent intermittent fasting from becoming intermittent feasting, people should maintain the same calories as their usual diet or gradually decrease their intake. Planning what to eat ahead of time and recording what you have eaten after mealtime can be a great idea to prevent overeating. It is also important to strictly stick to the time interval between fasting and mealtimes to maintain internal constancy of the body. In addition, a well-balanced diet consisting of high-protein and low-carbohydrate and muscular exercise are necessary to prevent muscle loss. People should also keep in mind that intermittent fasting is not suitable for everyone. It may not be appropriate for people who need balanced nutrient supplies such as pregnant women, adolescents and the elderly. In particular, patients with diabetes should avoid intermittent fasting because it can cause a hypoglycemic shock by lowering blood sugar. Therefore, before starting intermittent fasting, they should check their physical condition first.
In this era of overnutrition, intermittent fasting has become a new trend with many positive effects. A cautious approach, however, is needed because it also has clear side effects that should not be ignored. Sticking to intermittent fasting just because of its popularity without considering each individual’s physical condition can damage one’s health. Therefore, establishing eating habits and regular exercise that fit an individual’s life pattern and physical condition should be a Kingo’s top priority.