Adults vary in height and weight. They are not like mass factory-produced arti-cles all of which are identical. Internationally, hardly any adult is pleased with his or her appearance: the short want to become tall and the thin, fat. The obese want to desperately lose weight.

Nonetheless, all humans fall into three basic body types: tall, thin, lanky ectomorphs; stocky mesomorphs; and overweight endomorphs.

Men are more likely than women to be ectomorphs. Ectomorphs have a high metabolic rate. Their bodies have less muscle mass and very little fat. They arouse envy in the other body types because they can eat tasty, high-calorie foods and, with hardly any effort, manage not to gain weight.

Mesomorphs have some muscles. They have to make an effort to stay trim. They gain weight quickly but do not “bloat out” like endomorphs. The latter utilise calories inefficiently, have a low metabolic rate, cannot eat as much as they would like to, and wage a lifelong battle against weight gain.

The human body can also be categorised into various shapes, depending on the molding of the skeleton and the muscles. They can be rectangles, triangles (common pear shape), inverted triangles (apple), hourglass, spoon or diamond shapes. Body shape, like height, is determined by genes. Age, environment and lifestyle, however, do play a role.

In women, and to a lesser extent in men, as age creeps up and they reach menopause, belly fat tends to get deposited around the midriff. This is partly due to the hormonal changes that occur at that time. This means pear-shaped women can gradually change into apple-shaped.

Apple-shaped men and women have visceral fat deposited around the abdominal organs. This is the dangerous fat, which predisposes to the development of hypertension, heart disease and also, at times, cancer.

Gradual change into an apple shape occurs with age, slowing metabolism, lack of exercise, unhealthy diet, stress and poor sleep.

The waist-hip ratio (WHR) is a rough indicator of health and one of the measurements for obesity. It is calculated by dividing the hip measurement by the waist measurement. Women should have a WHR of 0.85 or less. Men should have a ratio less than 0.9.

Another calculation, the BMI (body mass index ), is calculated as weight divided by height in metre squared. Obesity is present when the BMI is greater than 30. This is usually associated with an apple-shaped body and its corresponding health risks.

A high WHR is associated with a threefold increase in mortality in older people. It also has a correlation with fertility. Women with a WHR greater than 0.8 are less likely to become pregnant without intervention and treatment. Men with a WHR less than 0.9 are more fertile and less likely to develop testicular and prostate cancer.

An apple-shaped person can become a healthier pear with concentrated and sustained effort:

• Aerobic activities such as walking, running, cycling and swimming should be done for 30-60 minutes a day. The amount of activity required to keep the weight in check is different for each one and has to be determined individually.

• As muscle increases, fat decreases. Muscle-strengthening with dumb-bells need to be done three to four days a week, for about 20 minutes. The key is to increase the number of repetitions. A 2-5 kilo weight is usually sufficient.

• Eating should be mindful. Snacks to be avoided in favour of fresh fruits and vegetables. Carbohydrates should be drastically reduced in quantity.

• Aim for a 12-hour fast every day. Eat the last meal at least an hour before bedtime, say at 8pm, so that there is a 12-hour gap before the next meal.

The writer is a paediatrician with a family practice at Vellore and the author of Staying Healthy in Modern India. If you have any questions on health issues please write to yourhealthgm@yahoo.co.in