People with a normal Body Mass Index (BMI) may have abnormal body composition or other health indicators such as blood cholesterol, triglycerides, blood sugar, or bone density.
Myth 1: If you're not overweight or underweight, you don't need to exercise.
To determine if you are overweight or underweight, an estimate should be made based on the Body Mass Index (BMI) or the difference between your current weight and the standard weight appropriate for your height.
People with a normal Body Mass Index (BMI) may have abnormal body composition or other health indicators such as blood cholesterol, triglycerides, blood sugar, or bone density.
Abnormal body composition means an inappropriate proportion of body fat. Some women may appear quite slim, but upon testing, their body fat percentage is still too high. A high body fat percentage includes two aspects: a high absolute amount of fat, and a low muscle component, leading to a relatively high fat content. Slim women are mostly in the latter category. This condition is mainly caused by insufficient exercise and, with age, a gradual reduction in muscle fibers after middle age.
For those with a normal BMI, exercise can alter body composition and the muscle-to-fat ratio, and improve the function of various body systems. Myth 2: Eggs contain a lot of cholesterol, so they are not suitable for middle-aged and elderly people.
Excess cholesterol in the blood is a risk factor for atherosclerosis. People are more aware of this, but they lack an understanding that cholesterol is a substance essential for human survival, leading to various misconceptions.
The human body has a large number of cell deaths and new cells every day. Taking red blood cells in the blood as an example, 0.8% are renewed daily. The cell membranes of these new red cells require a certain amount of cholesterol. Cholesterol is also the main raw material for synthesizing adrenaline and sex hormones and participates in the synthesis of vitamin D. Therefore, cholesterol has very important physiological functions.
Under normal circumstances, the cholesterol content in the diet should not be restricted too strictly. Currently, it is widely believed at home and abroad that the daily intake of cholesterol for healthy people should not exceed 300 mg; for those with high low-density lipoprotein (LDL) and patients with diabetes or cardiovascular diseases, the daily intake should not exceed 200 mg.
Although eggs contain a relatively high amount of cholesterol, they also contain many essential nutrients for the human body. It is recommended that healthy people eat one egg per day; for those with high LDL, diabetes, or cardiovascular diseases, eating one egg every two days is more appropriate.
Myth 3: Fruit is a snack, so it's optional.
Fruits contain minerals that the human body needs but cannot synthesize on its own, have strong antioxidant effects, contain vitamins that prevent cell aging, and include soluble fiber like pectin that can significantly lower blood cholesterol levels, making them very beneficial for human health. However, the proportion of Chinese people, especially men, who regularly eat fruit is very low.
An analysis of data from a 10-year follow-up study of one million people in the United States in the 1980s found that among people who did not eat or rarely ate fruit, the mortality rate from lung cancer was 1.75 times higher than that of people who regularly ate fruit. What component in fruit is responsible for this effect? Is it vitamins? Can taking commercially available vitamin supplements have the same effect? A further analysis of the relationship between lung cancer mortality and the use of vitamin supplements found that regular use of vitamins did not provide similar protection.
Nutritional immunology experts explain that vitamins in natural plants do not work alone, but in conjunction with other vitamins and nutrients. Because chemically synthesized vitamins are isolated from other vitamins and nutrients, and the proportion of components in the compound is not exactly the same as in nature, they cannot produce the same effects as natural vitamins.
Therefore, in daily life, fruit should be an important part of the daily diet and is by no means optional. For the general population, vitamin supplements should absolutely not, and cannot, replace the daily fruits and vegetables needed.