14 DAY TRIAL // A recent research has showed that skinny people can have a lot of visceral fat, the kind that is stored inside the abdomen, and which is the most dangerous, causing diabetes and other diseases.
In 2005, Katherine M. Flegal, a researcher at the Centers for Disease Control and Prevention, made a statistical analysis of national survey data on obesity to find an amazing result: mildly overweight adults had a decreased risk of dying, compared to those of healthy weight. This contradicts decades of research and thousands of publications, stating that being a little overweight is bad and that being obese is worse.
What confuses the public are the terms ‘overweight’ and ‘obese’. They are both related to body mass index (BMI), reporting one’s weight in kilograms by the square of his/her height in meters.
A BMI of 25 to 30 corresponds to an overweight person, while over 30 to obese people. The long-established knowledge says that Americans carrying excess fat are more vulnerable to death caused by heart disease, diabetes and cancer.
But Flegal’s study is sustained by lawyers, journalists, political scientists and other academics outside the medical profession: critics say fat is not as bad as generally believed. Many put the fight against obesity on the financial stake linked to drugmakers and weight-loss clinics.
In 2007, Barry Glassner, a sociologist at the University of Southern California, published The Gospel of Food: Everything You Think You Know About Food Is Wrong, stating that if we enjoyed more our food, rather than dieting and counting calories, our life would be happier and healthier, but all this is not based on any research.
The CDC estimated in 2004 that obesity means money loss in health care and lost productivity of about $75 billion each year. Slimmer Americans would be healthier, would live longer and pay less for their medical care and an increased competitiveness means more jobs and higher wages.
But if fat is not a main factor for heart disease and other serious diseases, a possibility raised by Flegal and others, then fighting extra-pounds is wrong. But those studying obesity dismiss this. "It’s obviously complete nonsense, and it’s very easy to explain why some people have gone astray," said Meir Stampfer, a professor of nutrition and epidemiology at the Harvard School of Public Health.
Stampfer's team has made decades-long researches on hundreds of thousands of people, founding the basis of the current knowledge about the dangers of being overweight or obese. "The reason being overweight seemed to reduce mortality is because Flegal used the wrong comparison group. The lean group in her study included smokers and people with chronic illnesses?"both of whom have increased mortality risks, but not because they are slim. When you get sick, you lose weight, and you die," said Stampfer.
In November 2006, James A. Greenberg, a researcher at Brooklyn College made a similar statistical analysis to Flegal’s, but by including factors like a history of serious illness. When he added these factors, the number of extra deaths for the obese compared to "healthy" weighted people tripled. He even detected a significant increase of the mortality risk in merely overweight individuals, which is quite the opposite of Flegal’s findings.
Flegal admitted she did not exclude the chronically ill individuals from her research, but she said that in a follow-up report it appeared it would not have made a difference. Flegal is not necessarily wrong, but the overwhelming evidence is different. "About every 10 years this idea comes along that says it’s better to be overweight. And we have to stomp it out," said Walter Willett, from Harvard School of Public Health.
Most Americans encounter difficulties in achieving a BMI of 25, on the line between the overweight and healthy, but Willett found that more weight loss means better health. "To take one example, people with a BMI of 20 who gain enough to reach a BMI of 25 have quadrupled their risk of diabetes. If they go up over a BMI of 30, they’ve increased their risk of diabetes 30- to 60-fold," said Willett.
Willett has also come with three numbers: a BMI maintained within the normal range (20 to 24.9), and preferably close to the low end of that range.
The second is how your weight shifts after age 20. "Although obesity has become increasingly common in children, most people who are now adults were probably close to their proper weight when they were 20," he said.
The third number points to the circumference of the waist: "The consequences of working on these three numbers will be huge benefits in health. But even small reductions in weight are beneficial. If people can lose 5 to 10 % of their weight, they will have done themselves a huge favor. If they can take another step, another 5 to 10 %, they will have done themselves another favor."