The Body Mass Index (BMI) is one of the methods for measuring overweight and obesity. It is calculated by dividing the body weight (in kg) by the square of height (in m): kg/m2. For Chinese adults living in Hong Kong, BMI from 23.0 to less than 25.0 kg/m2 is classified as overweight and BMI 25.0 kg/m2 or above is classified as obese.

Obesity increases the risk for chronic diseases, such as hypertension, heart diseases, hypercholesterolaemia, diabetes mellitus, cerebrovascular disease, gall bladder disease, osteoarthritis, sleep apnoea and some types of cancer (breast, prostate, colorectal and endometrial).

Prevention

A balanced diet and regular physical activity are the proven ways to achieve and maintain an ideal body weight.

Balanced diet

A balanced diet contributes to good health. It shall include a variety of foods providing appropriate calorie and nutrients. Members of the public are advised to follow the principles of the Healthy Eating Food Pyramid and include the five basic food groups (i.e. grains; fruit; vegetables, meat along with fish, eggs and legumes; milk and milk products) and be active in decreasing fat, salt and sugar intake.

Imbalanced or poor diet may lead to obesity or specific nutrient deficiency. These in turn may increase the risk of a variety of health problems, such as heart diseases, cerebrovascular disease, diabetes mellitus, hypertension and certain kind of cancers.

Adequate amounts of fruit and vegetable intake is an essential component of healthy eating. WHO recommends a daily intake of at least 400 grams of fruit and vegetables (about 5 servings of fruit and vegetables) for the prevention of chronic diseases such as heart diseases, hypertension, cerebrovascular diseases, diabetes and certain cancers.

There is sufficient evidence in humans that consumption of processed meat causes colorectal cancer. Members of the public are urged to avoid processed meat and associated products.

Regular physical activity

For adults aged 18 and above, including those living with chronic conditions or disability, the World Health Organization recommends that: They should do at least 150–300 minutes of moderate-intensity aerobic physical activity; or at least 75–150 minutes of vigorous-intensity aerobic physical activity; or an equivalent combination of moderate- and vigorous-intensity activity throughout the week, for substantial health benefits.

(Source: Department of Health)