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Obesity in Adult


Obesity is a complex, multifactorial condition characterized by excess body fat which resulted in excessive weight. In Malaysia, the National Health and Morbidity Survey 2011 reported that in adult. More than 18 years old, 33% were classified as pre obese and 27.2% were obese.

Generally men who have more than 25% body fat and women who have more than 35% is considered as obese. Obesity can be classified based on Body Mass Index (BMI) based on the following formula:

BMI: Weight (kg) / Height2 (m)2




< 18.5

Normal Weight












Table 1: Classification weight by BMI

Causes of Obesity

There are many factors that can contribute to obesity; among the key factors are excessive food intake which high in fat and sugar which exceed the daily requirement and lack of exercises and physical activities. There are several other factors that can lead to obesity, such as age, gender, genetics, internal diseases, and also taking certain medications such as steroids.

Health Risk

Obesity can cause a serious health implication as it can increase the risk of someone getting various disease.

Obese person has a higher risk of getting diabetes, fatty liver, metabolic syndrome, sleep disorder and breathing difficulties. They are also at moderate risk of getting stroke, coronary heart disease, heart failure, hypertension, gout and arthritis.


The general goals of obesity treatment are:-

  • Achieve weight loss
  • Prevent further weight gain
  • Treat underlying causes

A recommended weight reduction at the initial phase is a 10% weight reduction from baseline over 6 months of therapy example, 0.5kg to 1 kg per week. It is important to avoid a rapid weight reduction that may lead to increased risk of gallstones, electrolyte abnormalities and weight regain.

There are few strategies one can use to reduce weight:

Diet Therapy

Consuming Low Calorie Diet (LCD) and low fat diet is one of the important strategies in reducing weight. LCD provides a calorie deficit of 500 to 1000 kcal/d from daily maintenance requirement. LCD can reduce total body weight – average of 8-10% over 6 months for those in category moderate to severe obese.

Consuming Very Low-Calorie Diet (VLCD) between 200 to 800 kcal/day can result in more rapid weight loss. However this needs to be done under medical supervision. This therapy is not suitable for those with diabetes, stroke, liver disease, kidney problem and those with recent heart attack.


Physical activity plays an important role in weight reduction process. It favourably changes body composition, decreases risk for disease, and improves quality of life. Before the patient starts an exercise programme, the attending doctor must give medical clearance based on patient’s age, symptoms, concomitant risk factors and physical examination.

All exercise programmes should be introduced gradually. Thirty minutes of regular moderate intensity physical activity, preferably all days of the week, can limit health risks for chronic diseases including coronary heart disease and diabetes. However, to prevent weight regain for formerly obese individuals requires 60 – 90 minutes per day of moderate intensity activity.

Behaviour Therapy

Behaviour therapy is a useful adjunct when incorporated into the treatment for weight loss and weight maintenance. The goal of behaviour therapy is to alter the eating habits of an obese patient. This can be done through dietary counseling, support group, self-monitoring.

Medications / Drugs

Anti-obesity drugs may be considered in addition to diet, exercise and behaviour modification. A patient may require drug therapy:-

  • to help compliance with dietary restriction
  • to boost diet-related weight loss
  • to achieve weight maintenance after satisfactory weight loss.

Anti-obesity drugs can be used in certain medical conditions such as diabetes, hypertension, heart disease and arthritis. However Anti-obesity drugs are not recommended for children, pregnant women and those who have drugs allergy.

Anti-obesity drugs can be classified into two groups, those acting on the:

  • Gastrointestinal system to reduce fat absorption eg. Orlistat
  • Central nervous system to suppress appetite eg Sibutramine and Phentermine


Surgery is an option for weight reduction for some patients with severe obesity (BMI >40kg/m2), in whom efforts at other therapy have failed. Surgical approaches can result in substantial weight loss i.e. – from 50 kg to as much as 100 kg over a period of 6 months.

Commonly used surgical interventions include gastric bypass, gastroplasty and laparoscopic insertion of a gastric ring to reduce stomach size. Liposuction (cosmetic surgery used to remove unwanted body fat) is not a treatment for generalised obesity, but may be used for unsightly local collections of fat in the specific body area.


The best way to reduce obesity is to prevent it. These are things you can do to prevent obesity:

  • Exercise regularly
  • Avoid high sugar and high fat diet
  • Take small amount of food at every meal
  • Drink enough water at least 8 glasses per day
  • Eat when you are hungry and stop before you full
  • Avoid taking heavy meal before sleep or late night
  • Limit amount of television viewing and substitute with exercise session.
  • Monitor your weight once a week


  1. Ismail, I. S., Bebakar, W. M. W., & Kamaruddin, N. A. (2004). Clinical Practice Guidelines on management of obesity 2004. Putrajaya: Ministry of Health Malaysia, Academy of Medicine of Malaysia, Malaysian Association for the Study of Obesity, Malaysian Endocrine and Metabolic Society.
  2. World Health Organization. (2000). Obesity: preventing and managing the global epidemic (No. 894). World Health Organization.
  3. National Health and Morbidity Survey 2011, Kementerian Kesihatan Malaysia.
Last Reviewed : 28 August 2020
Writer : Dr. Shamsul Anuar b. Asmee
Translator : Dr. Zainal Fitri b. Zakaria
Accreditor : Dr. Sri Wahyu bt. Taher
Reviewer : Dr. Nor Faizah bt. Ghazali