Definition of Obesity

Obesity is the accumulation of excessive fat, or a high ratio of fatty tissue to other soft tissues inside the body. In other words, obesity is an over-nourished condition. It can also be interpreted as a disorder of calorie metabolism.

Obesity is mainly caused by unhealthy dietary habit and life style. Excessive intake of food, snacks, desert or unnecessary health complements leads to surplus of calorie. Without enough exercise to consume the calories, our bodies convert excessive calories into fat and store it inside our bodies. Clinical studies have shown that obesity is also inheritable, and people with this risk factor should pay more attention to their dietary habit.

 Balance diet


BMI Calculation

How to determine Obesity?

Body Mass Index (BMI) is the most common method to determine obesity. It takes the height and body weight into account. The formula of BMI is to divide body weight (in kg) by height (in m2)

In 2000, World Health Organization has established a scheme to assess BMI for Asian people: 

  Under-weight Standard Over-weight Obesity Extreme Obesity
Asian Adults 18.5 or lower 18.5-22.9 23-24.9 25-29.9 30 or more

Percentage Body Fat (% Body Fat) is another method to assess obesity. Obesity is not simply over-weighed but also having a high ratio of fat. The higher the Percentage Body Fat, the higher the ratio of fat inside the body. In general, male who has over 25% of Percentage Body Fat or female who has over 30% of Percentage Body Fat are considered obese.

Most of the people considered obese by BMI also have high Percentage Body Fat. A small portion of these people have more muscle or heavier bones such that they have high BMI but normal Percentage Body Fat. These people are not considered obese.


Impact of Obesity

With the increase of living standard and the change of eating habit, diseases related to obesity have been blooming, particularly in the USA and European countries where obesity has become a common health threat for city dwellers. According to a research in 1995, there are 38% of men and 34% of women in Hong Kong have obesity-related problems. Obesity can deteriorate the condition of hypertension or increase the risk of diabetes, heart diseases and other complications. In addition, obesity also increases the risk of cancers such as breast cancer and colon cancer.

In addition to these disorders, the fatty tissues near the necks of obese patients can compress the airway and affect breathing. This can lead to snoring, insufficient breathing or even pauses of breath. This is why Obstructive Sleep Apnea (OSA) is more common in obese people.


Ways to Lose Weight

The most effective way of losing weight is to have regular exercise and pay more attention to the diet. It is simple but requires persistency. Most people fail to lose weight only because of their lack of persistence.

Exercise that can help losing weight includes the follows. A balanced work out scheme is needed to achieve a good result:

  Aerobic exercises such as running, cycling and swimming require a good coordination of limb movement and breathing, and can reinforce the function of the heart and the lungs, at the same time reduce body fat.

  Weight training such as sit-up, dumbbell exercise and work out can train different muscles of the body for strength and endurance.

  Ball games combine the need for both kinds of exercise. They also have higher energy consumption.

exercise 2

Different health conditions do not respond to the same kind of exercise equally. Excessive exercise can wear off joints badly and damage muscles. Therefore, please take into account of your own health condition in performing exercise.

At the same time, the following dietary habit and life style are needed to achieve the best results:

  Eat more fruits and vegetables. Reduce intake of sugar and oil.

  Adapt a healthy life style such as work and rest for regular hours, sleep early at night and get up early in the morning, and quit smoking and drinking.

  Keep yourself in a good mood. Bad mood affects your appetite and absorption of nutrients. Fluctuating mood can also affect your metabolism and make weight-losing efforts ineffective.


Exercise and dietary change are long-term measures to lose weight. Taking them for a short period of time does not help losing weight. A healthy life style with a good diet and appropriate exercise can decrease the chance of rebound.


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