February 2, 1996. Copyright, 1996, Graphic News. All rights reserved

IS THE END OF OBESITY UPON US?
By Nicholas Booth, Science Editor

LONDON, February 2, Graphic News Ð When you have to be transported to hospital on a fork lift truck and your bedroom wall has to be demolished to remove your corpse, then itÕs pretty obvious youÕre obese. Last yearÕs revelations about the worldÕs fattest man Ð an American who weighed 73 stone (465 kilos) Ð may seem like an extreme statistic but not by much, report medical authorities worldwide. Obesity is one of the most common chronic diseases in the world, with an estimated one in three Americans and perhaps as much as a quarter of EuropeÕs population classified as clinically obese. The full price to be paid in human health terms from the disease includes greater chances of suffering from heart attacks, respiratory illnesses, diabetes, arthritic degradation of joints and hardening of arteries. 

Obesity, defined simply as the intake of energy greater than that used by the body, constitutes the second largest preventable cause of premature deaths after smoking. A balanced, healthy diet is half the battle against the disease, say health experts, who suggest that sedentary lifestyles and high fat diets have taken their toll worldwide. But why some people are prone to becoming obese is not fully understood. There are many underlying genetic, cultural, and behavioural factors, and as a result Ð despite recent media speculation over a number of scientific bre
akthroughs Ð it is clear that there will be no panacea in the battle against obesity.
Careful examination of claims surrounding one such ÔmiracleÕ solution, a new low fat substance, Olean, shows that the holy grail of a fat-free diet may not be without its share of problems. In the United States, Procter and Gamble have just received approval from the Food and Drug Administration (FDA) to use it in snacks, an industry with a $15 billion a year turnover. The company has developed the fat which passes through the gastrointestinal tract without being digested because its molecular structure is so large it cannot be broken down by enzymes in the stomach. Promotional material points out that Olean snacks will contain half the calories, none of the fat and will taste exactly the same as ordinary snacks. But the downside is that some nutritionists in the U.S. have warned that Olean will remove vitamins from the digestive tract and there may be unpleasant side effects. Time will tell whether the FDAÕs insistence that each snack must carry the announcement that ÔOlean may cause abdominal cramping and loose stoolsÕ will deter all but the most inveterate of American snackers. 

A less contentious solution may come from three complex molecules called tubby, fat and ob which have been artificially produced. They are genes isolated by researchers from DNA which seem to regulate obesity by producing a protein which suppresses appetite and causes weight loss when injected into mice. During trials of the first to be manufactured, ob, grossly obese mice lost from 22% to 40% of their weight after a month of injections. The protein in question is known as leptin and was isolated by researchers at Rockefeller University in the U.S. at the end of 1994. 

Rights to its patent were auctioned for a staggering $20 million and though there may be fat profits ahead for biotechnical companies, it will be many years before gene therapy will be available to patients in hospitals. Ultimately, although genetic factors are important, they alone cannot account for the explosion in obesity rates: stated simply, obesity rates are rising so quickly that they cannot be due to genetic defects alone and only 1% of cases of obesity seem to result from severe genetic disease. Another scientific approach is a form of biological liposuction, where the bodyÕs immune defences are tricked into thinking that fat cells should be eliminated by use of antibodies. Reductions in the number of fat cells have been reported in many animals by researchers at the National Institute for Medical Research at Mill Hill, north London, and ultimately this technique may be refined to allow obesity to be treated by injection. 

But, again, it may be many years before such techniques are clinically available and in the meantime, the best advice remains cut down on fatty foods, watch your weight and try to take more exercise.

Sources: Medical Research Council, World Health Organisation, International Journal of Obesity.

NOTE TO EDITORS: Next Wednesday, February 7th, a scientific meeting organised by the Association For The Study Of Obesity will take place in London. To find out if there are experts from your area attending, please call Nick Booth directly on (0171) 722 5561.