[Kim Jae-ho's Life Story]<205> A Special Helper for Obesity

The obese population is steadily increasing. According to the National Health Insurance Service's '2020 Health Information You Want to Know,' the obesity rate in South Korea rose from 30.5% in 2016 to 32.0% in 2018 among general health screening subjects, and the rate of severe obesity increased from 5.1% to 6.1%. Obesity causes various diseases and, if severe, can threaten life, so it is necessary to understand the characteristics of metabolism well to prevent and manage it properly in advance.

Living organisms constantly use chemical reactions to convert the chemical energy contained in food in the form of carbohydrates, proteins, and fats into the necessary forms of carbohydrates, proteins, and fats, and convert some of the chemical energy into kinetic energy to perform necessary activities. This metabolism also includes digestion, which breaks down large molecular nutrients in food for absorption, and the processing of waste products produced as byproducts.

The energy used and remaining from metabolism is stored in the form of carbohydrates and fats for future use, but not in the form of proteins. Glycogen, a form of carbohydrate, can be easily converted into glucose and is stored in the liver and muscles at about 500g for short-term storage, enough to last a day without eating. Stored glycogen is converted into glucose whenever blood sugar levels drop.

Normally, about 4g of blood sugar (glucose), enough for about 11 to 12 minutes of use, is present in the blood. When blood sugar is used and falls below the appropriate level, the pancreas secretes the hormone glucagon to convert stored glycogen into glucose to raise blood sugar. When blood sugar rises due to glucose absorption from carbohydrate digestion, insulin is secreted to convert blood sugar into glycogen to lower it, maintaining blood sugar at an appropriate level.

For long-term storage, fat, which is efficient for energy storage, is used and accounts for most of the stored energy. One gram of carbohydrate stores 4 kcal of energy, but fat stores 9 kcal, making it more efficient. Usually, enough energy is stored as fat to survive about a month without eating. There is a case of a man weighing 206 kg who fasted for 382 days and reduced his weight to 82 kg.

Obesity, a major threat to modern health, is a condition where excess energy is stored excessively. It basically occurs when energy intake exceeds the body's energy needs. Due to the characteristics of energy storage and blood sugar regulation, consuming a lot of processed or refined "bad carbohydrates" including sugar (see Life Story episode 202) is a major cause.

Bad carbohydrates are quickly digested, causing a large amount of glucose to enter the bloodstream at once, rapidly raising blood sugar. The pancreas secretes insulin to lower blood sugar, which causes cells to convert blood sugar into glycogen and store it in muscles and liver. When glycogen storage capacity is full, excess glucose is converted into triglycerides and stored in fat tissue.

The more bad carbohydrates consumed, the more insulin is secreted and the more triglycerides accumulate. When energy is needed, stored glycogen and fat should be converted into glucose and fatty acids for use, but due to the remaining insulin in the blood, this conversion is difficult, causing blood sugar to drop and the body to crave more sugar.

Among bad carbohydrates, sugar is broken down by digestive enzymes into one glucose and one fructose molecule. Unlike glucose, which is used as an energy source by all cells, fructose is mainly metabolized in the liver. When excessive sugar intake causes fructose to be rapidly absorbed and exceed the liver's metabolic capacity, most unused fructose is converted into triglycerides and accumulated in fat cells, becoming a major cause of obesity.

As seen above, consuming a lot of processed or refined bad carbohydrates including sugar acts as a special helper that rapidly increases fat storage, so it is advisable to limit intake. Among them, sugar contributes especially significantly to obesity, so numerous health organizations, including the World Health Organization (WHO), strongly recommend limiting sugar consumption.

However, this does not mean restricting all carbohydrates. It is good to consume sufficient amounts of good carbohydrates (see Life Story episode 202), such as those found in whole fruits, vegetables, and unrefined whole grains. Additionally, obese individuals should remember and practice eating a variety of plant-based foods, including fruits and vegetables of various colors, to ensure adequate intake of dietary fiber and antioxidants.

Jaeho Kim, Independent Researcher

This content was produced with the assistance of AI translation services.