Unlock the Surprising Truth: Why Weight Loss Isn’t Always the Answer as You Age

People generally gain weight when they reach middle age in their 40s and 50s. You gain what is known as belly fat and gain weight, weighing 15 to 20 kg more than when you were in your 20s.

The results of the health check are not good either. If your blood pressure levels, fasting blood sugar, or dyslipidemia (high triglyceride, low HDL cholesterol) are high, you will receive a ‘warning’ that metabolic syndrome is suspected. Metabolic syndrome is defined as waist circumference (over 90 cm for men and over 85 cm for women), high blood pressure (systolic blood pressure over 130 mm Hg or diastolic blood pressure over 85 mm Hg), fasting blood sugar (over 100 mg/ dl), and neutral fat (over 150 mg / dl).

For this reason, many middle-aged people try to lose weight (diet). Even when I’m starving, I exercise hard by walking around the house. However, losing weight is not that easy. As a result, they become discouraged with the excuse, “When I was young in my 20s and 30s, I didn’t gain weight even if I ate a lot and didn’t move much, but as I getting older, my metabolism isn’t as good as when I was younger, so I don’t lose weight as easily.” However, this excuse turned out to be false.

A scientific team including more than 80 people from 29 countries around the world carried out an international joint survey over 5 years using a method called the ‘double index method’ on the total energy consumption of 6,421 men and women aged 8 days to 95 years old. As a result, it was confirmed that the total daily energy consumption hardly changes from the mid-20s to around the age of 60. Even when adjusted for body size, there was little change in the total energy consumption of people in their 20s to 60s. Energy consumption decreases after the age of 60. This means that there is no difference in metabolic capacity whether you are in your mid-20s or your 60s.

The research team applied rigorous measurement methods to people living in various environments in each country, including developed countries, low-income countries, people living in the highlands, and people living a hunter-gatherer lifestyle . The double index method is a survey technique created to evaluate energy use or physical activity, and is known as the most objective method to measure energy use in daily life. The results of this study were published in the international scientific journal ‘Science’ in 2021.

Until now, it was a common belief that one’s metabolism declines with age. In other words, the decline in metabolism as one enters one’s 30s, 40s and 50s is thought to be the cause of weight gain during middle age. However, research results showing that ‘metabolism hardly changes between the ages of mid-20s and 60’ have changed this common belief. This was also true of changes in basal metabolism. Until now, metabolic research has focused on basal metabolism, which accounts for 50-70% of total energy consumption. Basal metabolism refers to the minimum energy metabolism required to sustain life.

In order to live, our whole body needs energy to function, and that energy comes from eating. This is called ‘absorbed energy’. The energy obtained from swallowing is used to move the body, and this is called ‘consumption energy’. Simply put, weight change is determined by the difference between energy intake and energy expenditure. If daily intake and consumption are the same, there is no change in weight If intake is greater than consumption, you gain weight, and if it is below consumption, you will lose weight. Energy consumption and metabolism are closely linked. Metabolism is ‘basic metabolism (energy used by organs in the body even when sitting still)’, ‘active metabolism (energy used when moving the body)’ and ‘heat production caused by meals (energy used by creating body heat during digestion and absorption). after a meal).’ There are three things: The total of these becomes the total metabolic rate, that is, the total energy consumption.

So, why do middle-aged people gain weight and develop abdominal obesity even though their metabolism does not decline?

The Nippon Keizai Shimbun published an analysis by Yosuke Yamada, associate professor at the Graduate School of Public Health at Kobe University in Japan (Director of the Exercise Guidelines Research Department, Physical Activity Research Department, National Research and Development Institute for Pharmaceutical, Health and Nutrition Sciences ), who participated in the ‘International Total Energy Use Research Team’ Professor Yamada chose four real cases of middle-aged people gaining weight.

The first cause is ‘the habit of overeating every day, even if only a little.’ Although it is only a small amount, it is noted that if the total calorie intake is greater than the total energy used each day, it can cause obesity. For example, Professor Yamada claims that even if you eat only 10 kcal excess per day, if this continues for 20 years, your body weight will increase by 10 kg. It is calculated that body weight increases by 1.4kg per day, but it is not easy to realize that you are gaining weight every day. He said, “Originally, our body is supposed to automatically maintain a balance so that there is no change in weight when the weight is more than 10 kcal. However, that balance function is performed under the precondition of being active always. Many modern people lead and ‘live without moving much’ He explained, “If that happens, the natural balance function of human beings will not work, so ‘total energy intake = total consumption of energy’.” So, even if you eat 10 kcal too much every day, your weight will gradually increase.

Along with this, you should also be careful about times when you tend to overeat, such as holidays, vacations, weekends, birthdays, company dinners, etc. It’s easy for people to gain weight in winter, especially since many people go on holiday from December 20 around Christmas to the beginning of the year, and they have a habit of eating a big feast during this time , so there is a high. possibility of weight gain.

Holiday weight gain is generally known as ‘holiday weight gain’. As a result of analyzing weight changes during the week (1,421 people), holidays (1,062 people), and seasons (1,242 people) in Europe, it was found that weight increases on Saturday, Sunday, and Monday, and reduced on Wednesdays and Thursdays. .

zoom in picture

The second cause is ‘lifestyle habits that don’t move well’. This tendency becomes stronger as one reaches middle age. People in their 20s often walk and wander around even on weekends. However, as people enter middle age, they often use subways, buses and taxis rather than walking, and tend to relax at home on holidays. Even if the signal at an intersection is flashing, they don’t rush to cross quickly. In fact, looking at the Japanese case, the average number of steps decreases with age. According to the ‘National Health and Nutrition Survey Report 2019’ published by Japan’s Ministry of Health, Labor and Welfare, the average number of steps for men in their 20s is 8,301 steps, while for those in their 60s, the number of steps decreases by 1,542 steps to 6,759 steps. A reduction in the number of steps leads to a reduction in total energy consumption. There is also a research report that shows that the total daily energy consumption of office workers in their 30s is around 2,800 kcal, but telecommuters of the same age use drops to around 2,400 kcal. This is consistent with the increase in people gaining weight as telecommuting spreads during the COVID-19 pandemic.

The third cause is ‘deterioration in muscle quality’. The muscle quality of people in their 20s and middle-aged people is different. Muscle cells (myofibers) are fibrous cells with contractile properties that make up muscle tissue.

When muscle quality declines, it becomes difficult to expend energy even when moving the body. The reason why the peak age of sports players is said to be around 30 is because even if muscle mass is maintained through training, it is difficult to maintain muscle quality, leading to poor performance.

It has been confirmed that muscle quality is better in people who regularly walk properly. When muscle quality declines, muscle flexibility decreases, movement becomes difficult, and vitality decreases. When vitality decreases, we fall into a vicious cycle that leads to a decrease in step count.

zoom in picture

The fourth cause is a reduction in brown fat cells, which exist mainly around the collar bone or chest and burn fat to produce heat. When you gain weight, fat (body fat) accumulates in your abdomen first. If body fat accumulates next to organs such as the stomach or small intestine, it is called ‘visceral fat’, and if it accumulates under the skin of the abdomen, it is called ‘subcutaneous fat’. Subcutaneous fat is mainly found in women, and when touched, it is soft and thick and can be grasped with the fingers. Visceral fat accumulates around the abdominal organs and is not easily removed.

Visceral and subcutaneous fat are divided into ‘white fat cells’ and beige colored ‘brown fat cells’ depending on the role and function of the stored fat cells. White fat cells store energy, provide insulation to protect the body from extreme temperatures, and act as a cushion to protect flexible organs. Brown fat cells maintain body temperature when it’s cold and help the body burn calories. Specifically, the colder it is, the more activated brown fat cells become. Brown fat cells exist from childhood to the 20s, but they almost disappear in the 30s and 40s. Professor Yamada explained, “Even if the metabolism does not change between youth and middle age, the power to burn fat weakens,” adding, “Even if you overeat the same size, there is a possibility that fat accumulation may occur more easily in middle age than when you were young.”

Brown fat cells become more active the more time someone spends outside in cold weather, but modern people live in well-heated places from a young age, which is not giving brown fat cells a chance to show their abilities.

In this way, a decline in metabolic capacity is not the cause of middle-aged people gaining weight. Ultimately, the way to escape obesity is to increase total energy intake. To achieve this, we need to avoid sitting longer than we do now and increase physical activity (daily activities + exercise).

Middle-aged people walk or participate in equivalent physical activity for more than 60 minutes a day (more than 8,000 steps a day) and exercise for more than 60 minutes a week to the point where they are out windy and sweaty (muscle exercise 2 to 3 days a week). Elderly people walk or take part in equivalent physical activity for more than 40 minutes a day (more than 6,000 steps a day). Exercise, including strength training, aerobic exercise, balance exercise, and flexibility exercise (stretching) is recommended at least 3 days a week.

[이병문 의료전문기자]