Overnutrition: obesity
Obesity is excess body fat that harms health. Indians are judged by lower Asian BMI cut-offs (obese at 25 and above) because risk rises at lower weights.
Classifying body weight
| Class | WHO international | Asian cut-offs used in India |
|---|---|---|
| Underweight (BMI) | Below 18.5 | Below 18.5 |
| Normal (BMI) | 18.5-24.9 | 18.5-22.9 |
| Overweight (BMI) | 25.0-29.9 | 23.0-24.9 |
| Obese (BMI) | 30.0 and above | 25.0 and above |
| Abdominal obesity (waist) | Men above 102 cm, women above 88 cm | Men 90 cm or more, women 80 cm or more |
Causes of obesity
| Factor | Examples |
|---|---|
| Diet | Fried snacks, sweets, bakery items, sugary drinks, large portions, frequent eating out |
| Physical inactivity | Desk jobs, vehicles instead of walking, screen time, few playgrounds |
| Genes and family | Obesity runs in families through shared genes and shared eating habits |
| Age, sex and life stage | Risk rises with age; women after pregnancy and menopause |
| Hormones and medicines | Hypothyroidism, Cushing's syndrome, PCOS, steroid drugs |
| Psychological and social | Stress eating, poor sleep, urbanisation, higher income, feasting customs |
Two patterns of fat
At the same BMI, Indians carry more body fat, especially around the abdomen (the 'thin-fat Indian'). That is why lower BMI and waist cut-offs are used in India.
Health consequences
- Type 2 diabetes, hypertension, coronary heart disease, stroke, high blood lipids.
- Fatty liver and gallstones.
- Osteoarthritis of the knees, back pain.
- Sleep apnoea and breathlessness.
- PCOS, infertility and problems in pregnancy.
- Some cancers (breast, colon, uterus).
- Low self-esteem; teasing and bullying of obese children.
Preventive strategies
- Healthy diet (ICMR-NIN Dietary Guidelines for Indians, 2024): whole grains and millets, pulses, plenty of vegetables and fruits; limit oil, sugar, salt and ultra-processed foods.
- Physical activity (WHO): adults at least 150 minutes of moderate activity a week; children and adolescents an average of 60 minutes a day.
- Behaviour change: smaller plates, no eating in front of screens, regular meals, enough sleep.
- Schools: healthy canteens, daily sports, Eat Right School and Fit India School programmes.
- Screening: BMI, waist and blood pressure checks at PHCs and health and wellness centres under the national NCD programme.
- Campaigns: FSSAI's 'Aaj Se Thoda Kam' (cut oil, sugar and salt a little at a time) and the Fit India Movement.
In a community health camp, measuring weight, height and waist picks up the 'thin-fat' adult with a normal-looking body but a large waist. Teaching families to cut oil a little each month and walk daily works better than crash diets.
2 marks: “State the Asian BMI cut-offs for overweight and obesity.” Overweight: 23.0-24.9 kg/m²; obesity: 25 kg/m² and above.
5 marks: “Differentiate android and gynoid obesity.” Android: fat on the abdomen, common in men, high risk of diabetes and heart disease. Gynoid: fat on hips and thighs, common in women, lower risk. Add the waist cut-offs (90 and 80 cm).
10 marks: “Define obesity. Discuss its causes, health consequences and prevention.” WHO definition; BMI table with Asian cut-offs; NFHS-5 figures; causes table; android versus gynoid; consequences; prevention through diet, activity, schools, screening and campaigns.
23 to worry, 25 to act: Asian BMI 23 is overweight, 25 is obese. Waist: 90 for him, 80 for her.