Recently, health and its link to a person's ideal body weight have come to limelight in the wake of death of a Brazilian model from complications of eating disorder. Anorexia is a common eating disorder in which sufferers obsessively deprive themselves of food in pursuit of an ultra-slim look. Earlier in the same year another model from Uruguay died of heart failure during a fashion show. This prompted Madrid autumn fashion show 2006, to ban five underweight models from the prestigious fashion event. Many cities are considering following Madrid's lead in banning thin underweight models from the fashion parade. Madrid organiser did not allow women below a predetermined Body Mass Index (BMI) citing reasons that skinny role models are bad for nation's health.

What is BMI?
BMI is a measure of body weight relative to height that health care professionals normally apply to study obesity. According to the World Health Organisation (WHO), Body Mass Index is a simple index of weight-for-height that is commonly used to classify underweight, overweight and obesity in adults. It is defined as the weight in kilograms divided by the square of the height in metres (kg/m2). According to WHO, a normal BMI range is 18.5 to 24.99. A BMI of 25 to 29.9 is considered overweight, and a BMI of 30 or more is considered obese. A BMI of less than 18.5 is considered underweight. In the case of the Madrid show, organizers rejected women with a BMI below 18. Another important measurement for healthy body weight, an indicator for obesity, is Waist-Hip Ratio (WHR). The WHR looks at the proportion of fat (weight) stored on body around waist and hip. It is a simple but useful measure of fat distribution. The WHR is calculated by dividing waist measurement (around navel just above the belly button) by hip measurement (widest part of buttocks). A WHR under 0.85 is healthiest for women and under 0.9 for men. Recent studies suggest that abdominal fat plays a role in the development of high blood pressure, high cholesterol, and heart disease. So, increasing waist size can serve as a warning that everyone ought to take a look at how much he or she is eating and exercising.

Obesity and its management
The WHO global database on BMI was developed way back in 1997 for facilitating international comparisons of adulthood obesity rates, monitoring the magnitude of the current and future obesity problems, and evaluating the effectiveness of intervention strategies. Obesity, as mentioned above, is defined as surplus body fat that results in a weight that exceeds a person's ideal body weight. Obesity afflicts more people in the industrialised nations than does any disease.

For obese people who have difficulty losing weight through diet and exercise alone, there are a number of FDA-approved prescription drugs that may help. Drug therapy may be used for weight loss and weight maintenance. However, weight loss medications should always be combined with a programme of healthy eating and regular physical activity. Weight loss drugs, approved by the US FDA for treating obesity, are Orlistat and Sibutramine for long-term use; Diethylpropion, Phendimetrazine and Phentermine for short term use. All of the prescription weight loss drugs work by suppressing the appetite except for Orlistat, which is a lipase inhibitor. Until September 1997, two other drugs, Fenfluramine and Dexfenfluramine, were available for treating obesity. Fenfluramine, for treating obesity was marketed in 1973 and Dexfenfluramine, also for treating obesity in 1996. The manufacturers of these drugs voluntarily withdrew them from the market after spontaneous ADR monitoring reports suggested that they were the likely cause of heart valve abnormalities and pulmonary hypertension.

Underweight matters
Contrary to popular believe, 'thin body is better than fatty one,' being ultra-thin carries its own health risks. The fact, according to experts, remains that those who struggle with staying too thin suffer from the same problem as the obese. Underweight can increase risk of osteoporosis and fertility problems, weaken body's immune system, and cause other health problems. The death of two models and subsequent banning of ultra-thin models in the Madrid fashion show have revived interest and curiosity in healthy weight and its control and management.

Overweight and underweight problems
The World Health Report 2002 identified top ten risk factors in terms of the burden of disease they cause. Two of the most striking findings of the report concern food consumption - either too much or too little. According to the report, at the same time there are 170 million children in poor countries who are underweight - there are more than one billion adults worldwide who are overweight and at least 300 million who are clinically obese. Until recently, the factor obesity had been things to be the result of over nutrition among the rich, wherever they live. Today, the rich women eat less to lose weight in pursuit of an ultra-slim look with more curves or muscle. The reason in which people strive to get thin has direct link with the fashion industry. Our world has extremes - people cannot eat normal food due to poverty on the contrary there are people who eat five star food that do not fill the stomach at all. In this context, we can relook the statement of Mark Twain, who once said, "The only way to keep your health is to eat what you don't want, drink what you don't like, and do what you'd rather not."

(The author is Reader in Pharmacy,Annamalai University, Annamalainagar 608 002, Tamil Nadu.Email: cdl_scbasak@sancharnet.in)