Overweight and obesity are an abnormal or excessive fat accumulation that presents a risk to health. It is a risk factor
for many diseases and is linked to many deaths. Body mass index (BMI) is a simple index of weight-for-height used to classify overweight and obesity in adults.
BMI = Weight (in kilograms)/ Height (in metres) squared (m2)
Interpretation of BMI values in adults
CLASSIFICATION | CRITERIA |
---|---|
Underweight | BMI <18 |
Healthy body weight |
BMI 18 to 25 |
Overweight | BMI 25 to 30 or waist circumference >88 cm (F) or >102 (M) |
Obesity | BMI >30 or waist circumference >88 cm (F) or >102 (M) |
In children, age needs to be considered when defining
overweight and obesity
CLASSIFICATION | CRITERIA |
---|---|
Underweight | BMI <18 |
Healthy body weight |
BMI 18 to 25 |
Overweight | WFH >2 standard deviations above WHO Child Growth Standards median |
Obesity | WFH >2 standard deviations above WHO Child Growth Standards median |
Causes
- High energy (i.e. calorie) intake: eating too much, eating a lot of fatty food
- Low expenditure of energy: sedentary lifestyle, no exercise or limited activity
- Disease: hypothyroidism, diabetes mellitus, pituitary cancer
Raised BMI is a major risk factor for:
- Cardiovascular disease: heart disease and stroke
- Diabetes mellitus
- Musculoskeletal disorders: osteoarthritis
- Some cancers: endometrial, breast, ovarian, prostate, liver, kidney, gallbladder, kidney
- Obstructive sleep apnoea
- Fatty liver, gallstones
Clinical features
- Overweight
- Difficulty breathing
- Poor sleeping patterns
- Joint damage due to weight
- Low fertility
- Poor self-image, antisocial, depression
- In children, also increased risk of fractures, hypertension, cardiovascular disease, insulin resistance
Investigations
- Blood pressure
- Blood glucose
- Cholesterol
MANAGEMENT
- Advise patient to reduce carbohydrate and fat intake and increase fruit, fibre and vegetable
intake - Refer patient to a nutritionist for individualised diet counselling, and to compile a diet plan
- Advise patient to control appetite, participate in hobbies, treat any depression
- Advise patient to increase physical activity and exercise daily. Advise to start slowly and build up
gradually - Warn the patient of their high risk of diabetes, heart disease, hypertension, stroke, and general
poor health - Encourage patient not to give up even when the weight loss process is slow
Prevention and health education
- Society and community choices: make healthier food the most accessible, available, and affordable food, and regular physical activity
- Individuals should:
- Limit energy intake from total fats and sugars: reduce fatty meat, palm cooking oil (replace with sunflower, olive, corn oil)
- Increase consumption of fruits and vegetables, as well as legumes, whole grains and nuts
- Engage in regular physical activity (60 minutes a day for children and 150 minutes spread through the week for adults)
- Stop other habits that increase risk of non-communicable diseases, e.g., tobacco smoking, alcohol abuse