Lack of exercise and metabolic imbalance: the cost of obesity in modern "effortless" society

**Motor Factors**

Lack of exercise is another major factor contributing to obesity.

Insufficient exercise not only reduces energy expenditure but also puts the body in a metabolic state where energy is easily stored. In fact, when exercise is insufficient, the blood sugar-lowering effect of insulin weakens, creating a state of insulin antagonism. Due to the antagonistic effect of insulin, compensatory increases in insulin secretion occur. While the blood sugar-lowering effect is weakened, the function of fat synthesis remains unchanged, resulting in a metabolic state of fat accumulation. Even more concerning, in a state of insufficient exercise, basal metabolism decreases, energy storage increases, and the activity of fat-synthesizing enzymes becomes hyperactive. In reality, the correlation between insufficient exercise and obesity is more due to changes in metabolic state than to reduced energy expenditure.

Insufficient physical activity has become a significant cause of obesity in modern society, increasingly impacting our daily lives. Improvements in transportation, electrification of household chores, and reduction in manual labor have created a "labor-saving" society. Therefore, it seems logical that the stagnant adult diet over the past decade has led to a dramatic increase in obesity.

The American journal *Preventive Medicine* once pointed out that while cars have become an increasingly important means of transportation in modern life, they have also caused certain harms to people's health. The book states that the longer a person drives, the larger their waistline will become, which can directly lead to obesity.

Researchers conducted a two-year follow-up study of more than 10,000 residents of Atlanta, Georgia, and found that for every 30 minutes of additional driving time, the risk of obesity increased by 3%. Frequent drivers had a 7% higher rate of obesity compared to frequent walkers.

The United States is known as the "nation on wheels," with as many as 91% of respondents saying they generally don't walk when they go out, and most of them spend more than an hour a day in their cars.

Frank, the lead investigator, pointed out: "The more you drive, the more likely you are to gain weight; while the more you walk, the less likely you are to gain weight. People should re-examine their lifestyles and avoid driving for too long."

**Disease Factors**

Obesity caused by medical conditions is classified as secondary obesity. The most common type of obesity in daily life is simple obesity, accounting for the vast majority of obese individuals. However, some diseases caused by neurological, endocrine, or metabolic disorders can also lead to obesity.

Diencephalic obesity is a type of obesity caused by disease, such as obesity resulting from encephalitis or diencephalic trauma (due to brain injury). These patients often experience symptoms such as fluctuating appetite, abnormal sleep rhythms, erratic body temperature, blood pressure, and pulse, generalized obesity, and decreased sexual function.

Adrenal hyperplasia and adenoma leading to hyperadrenocortical function can also cause obesity. Obesity is particularly prevalent in the face, neck, chest, and abdomen, resulting in a round, moon-shaped face. There are no significant changes in the limbs, but purple striae appear on the abdomen and thighs. Patients may also experience hirsutism, and women may exhibit masculinization, amenorrhea, or menstrual irregularities, while men may experience impotence.

**Drug-related factors**

Obesity caused by medication is classified as drug-induced obesity. It is particularly important to note that women taking birth control pills may experience weight gain.

The main components of most clinically used contraceptive drugs are synthetic estrogens and progestins. Based on their different functions, they can be broadly classified into three categories: ovulation-inhibiting, implantation-resistant, and uterine-functional-affecting. According to their main components, dosage form, usage, and route of administration, they can also be divided into different types such as combined contraceptives and sequential contraceptives.

A small percentage of women (2%–5%) may experience weight gain after taking birth control pills. This is related to the slightly higher levels of estrogen and progesterone in the previously used pills, as well as the woman's individual constitution. For example, the progesterone in birth control pills can affect the body's anabolic processes, leading to weight gain. Estrogen can cause water and sodium retention, which can also contribute to weight gain.

Weight gain after taking birth control pills is related to individual constitution. Currently used third-generation birth control pills, such as Noregrexate (NGM) and Gestodene (GSD), have significantly reduced the content of estrogen and progesterone. It can be said that using these types of birth control pills has almost no adverse effects on glucose metabolism, lipid metabolism, or blood, and will not cause weight gain for the vast majority of users. However, a very small number of women who are more sensitive to these drugs may still experience this problem. Fortunately, this situation will quickly disappear after discontinuing the birth control pills. If a woman experiences weight gain after using birth control pills, it is best to consult her doctor promptly to switch to a newer birth control pill or adopt other methods of contraception.