Obesity occurs when the body accumulates too much fat, to the point of harming health. The main cause is consistently taking in more energy from food than the body burns each day, combined with other factors such as eating habits, low physical activity, genetics, stress, insufficient sleep, and sometimes certain illnesses or medications. Understanding the true cause helps you plan weight loss that is targeted and sustainable.
How to tell if you are overweight or obese
The basic tools used for assessment are body mass index (BMI), calculated from body weight (in kilograms) divided by height (in metres) squared, and waist circumference, which reflects fat build-up in the abdomen.
- BMI 18.5–22.9 — within the normal range
- BMI 23–24.9 — overweight; you should start being careful
- BMI 25 and above — meets the criteria for obesity; you should take it seriously
- Waist circumference — men should not exceed 90 cm, women should not exceed 80 cm. Exceeding this counts as "abdominal obesity," which carries an especially high risk of chronic disease.
Why being overweight is dangerous
Excess fat, especially abdominal fat, affects the function of insulin and the blood vessels, raising the risk of type 2 diabetes, high blood pressure, high blood lipids, heart and cerebrovascular disease, fatty liver and sleep apnoea. It also adds load to the knee and hip joints, leading to earlier joint degeneration.
Even a small reduction helps a great deal
Research shows that losing just 5–10% of your body weight can meaningfully lower blood sugar, blood pressure and blood lipids. You do not need to become very slim straight away. What matters is a realistic target that you can reach and maintain.
Losing weight the right way, step by step
The heart of sustainable weight loss is gradually rebalancing your energy intake alongside changes to your daily habits — not crash dieting.
- Eat a balanced diet, emphasising vegetables, fruit that is not too sweet, lean protein and whole grains
- Cut down on sugar, sweet drinks, fried food and processed food, and keep your portion sizes reasonable
- Exercise regularly, at least 150 minutes per week, together with muscle-strengthening exercise
- Get enough sleep, manage stress, and drink water instead of sweet beverages
- Aim to lose about 0.5–1 kg per week, and keep a record to track your progress
At Doctor Chat Clinic, care is provided by a doctor, with health check-ups, blood tests and follow-up. We help assess your BMI, waist circumference and the risk of conditions that come with excess weight — such as diabetes and high blood lipids — and give weight-loss advice suited to each person's health.
Avoid the wrong ways to lose weight, and the warning signs to see a doctor
- Severe fasting, or eating only one meal a day for a long time, risks nutritional deficiency and weight rebound
- Weight-loss pills or supplements of unknown ingredients may contain substances harmful to the heart and liver
- Rapid, unintentional weight loss, palpitations, severe fatigue, or swelling of the body should be seen by a doctor