Say no to obesity | Updated: 2022-08-23
Many studies show that various chronic diseases are increasingly afflicting young people, especially those who are overweight and obese. Preventing obesity and keeping a healthy weight makes people not only more beautiful but also healthier. 
What constitutes obesity?
Currently, BMI is the commonly used indicator to measure body fatness and health. Its computational formula is BMI = weight ( in kilograms) ÷ the square of height (in meters).
The normal BMI range for healthy Chinese adults (18 to 64 years old) is 18.5 to 23.9. A BMI≥24 means the subject is overweight. A BMI≥28 indicates obesity. People over 65 can have a slightly higher body weight and BMI.
Children and adolescents can be judged by the BMI criteria of different genders and ages provided by the guideline of "Screening for overweight and obesity among school-age children and adolescents” (WS/T 586-2018).
Science-based diet is the key
Preventing obesity requires a balanced diet and exercise. Food diversity is the basic principle of a balanced diet. It is advisable to take at least 12 kinds of food a day and 25 kinds of food a week. The diet should include five major categories of foods, in decreasing order: the first category is cereal and potatoes, the second is vegetables and fruits, the third is animal-based food, the fourth is beans and nuts and the fifth is cooking oil and salt.
The energy from everyday food intake should not exceed the energy needed by the human body. Vegetables and fruits are low in energy and rich in vitamins, minerals, and dietary fiber, and thus are good for preventing obesity. The fat content of livestock meat is often higher than that of poultry, fish and shrimp. 
Studies show that the carbohydrate energy supply ratio should be between 50% and 65%. Fried ingredients contain much more energy than steamed and boiled ones. Highly processed food is often easier to digest and absorb than minimally processed food, which is not good for weight control. 
Exercise is the guarantee
Obesity essentially results from more energy being taken in than consumed. A balanced diet and exercise can keep a healthy weight. 
Adults aged 18 to 64 are advised to schedule 150 to 300 minutes of moderate-intensity aerobic activities or 75 to 150 minutes of high-intensity aerobic activities, or equal amounts of moderate and high intensity aerobic activities per week. They should indulge in strength exercises at least two days every week. Children and adolescents aged 6 to 17 should have at least 60 minutes of moderate to high-intensity body exercise every day, and should take muscle strength exercises and bone strengthening exercises at least three days a week. They should reduce sedentary behavior to less than one hour per day, and their screen time should not exceed 2 hours a day. 
Exercise can be in varied forms and involve different kinds of sports, which may develop into daily habit. Physical exercise can improve health and is definitely not a waste of time.