Health hazards associated with being overweight have been recognised for decades, but the risks of being underweight are now also being acknowledged. A person’s body weight is the total weight they carry without any added items and is evaluated according to their height. The Body Mass Index (BMI) is used to determine if body weight is within a normal range, with a BMI of 18 to 25 considered normal. Many young girls and boys undergo dieting to reduce weight and remain slim. The fad to remain slim is associated with the concept that it looks attractive. In a bid to achieve that, many youngsters resort to many measures including starving, literally. A young person may eat very little to “watch weight”, then indulge in episodes of overeating. This deprives the person of the nutrients necessary for the healthy functioning of the body. The result is anaemia and protein-calorie deficiency. The overall resistance of the body is reduced, making it more prone to diseases. Lack of the necessary quantity of food and fibre in the diet can cause constipation and related gastric disorders. Consequently, there is a loss of appetite, reducing the intake further and making the person feel sicker. A person not eating enough will get tired easily and feel depressed. Thus affecting both physical and mental health. Crash dieting destroys the beauty of the face of a person, thus defusing the very reason for which it was undertaken. The long-term consequences of this kind of dieting are also harmful. Women have an increased requirement for iron and calcium during adolescence, pregnancy, lactation, and menopause. If not fulfilled, it can lead to anaemia and softening of the bones. This results in easy fatigue, backache, and various kinds of aches and pains in the body. The capability of the body to take food and assimilate is also reduced if the intake is not adequate for a long time. Afterward, if the affected person wants to increase the number of meals taken, it becomes difficult because the digestion becomes weak. A woman’s body is shaped differently from that of a man due to hormonal effects. The shape of the breasts, and buttocks is due to deposits of fat. Lack of fat induced by dieting can cause menstrual disorders and even sterility. Recent studies have shown that being underweight or undernourished also increases the risk of chronic non-communicable diseases like hypertension and diabetes in both men and women. Obesity is a precursor of many diseases like high blood pressure, diabetes, heart disease, etc. Besides, an overweight person is mostly unable to do active physical work and tends to get tired easily. They experience breathlessness when walking a few steps and cannot walk or work much. Therefore, to remain healthy, it is important to maintain a normal body weight. But the healthy way to achieve this is to avoid being overweight by doing regular physical exercise as per one’s capacity. Non-fattening foods like fruits, vegetables, and fish can replace fatty foods like chocolate, cheese, etc. Alcohol is best avoided. Fresh fruit juices should replace sodas. An underweight person should increase the number of calories in the food which can be obtained from carbohydrates, proteins, and healthy fats. Regular physical exercise is also helpful for an underweight person. The motto should be to eat a well-balanced diet and work hard physically. This will keep the body slim and healthy and boost immunity, which is very important for fighting infections. The writer is a specialist in internal medicine. rachna212002@yahoo.co.uk