Genetics, Obesity & FTO
Many overweight people claim that no matter how much they diet and exercise, they can't drop the pounds. Their slim friends no doubt imagine midnight cookie fiestas are to blame: lapses in the so-called diet, snafus in the work-out routine. But growing evidence suggests that in fact, genes may be at least partly to blame for obesity -- with a caveat.
In 2007, a research team at Peninsula Medical School in Great Britain discovered a gene called FTO that helps to regulate the amount of fat in the body. This gene occurs in over half of all people of European descent, with 16 percent of the population having two variants of FTO. Those with the two variants of the gene had an average weight 6.6 pounds heavier than those without the gene.
"If you do have the FTO gene, it does put you at risk for becoming obese and having type 2 diabetes and extra body fat," dietician Emily Rubin says in a news item on ABC. Other genetic factors also are indicated, including 11 DNA mutations discovered by researchers at the University of Florida. These mutations disable an appetite-suppressing hormone called leptin. And another genetic mutation that seems to slow metabolism was just discovered by researchers at the University of Chicago.
Do these discoveries mean that we can blame genetics for the spike in obesity worldwide? Well, genetics may play some role -- certainly those without a genetic predisposition to excess weight have an easier time staying thin. But genetics haven't changed in the last 25 years as the developed world has gotten fatter. And by the way, it isn't just the developed world that's packing on more pounds. According to the World Health Organization (WHO), "this increase is often faster in developing countries than in the developed world."
If genetics are to blame and genetics haven't changed, why have obesity rates at least tripled since 1980 in the United Kingdom, Eastern Europe, the Middle East, the Pacific Islands, much of North America, Australasia and China? You've probably seen the statistics;
- More than 1.6 billion adults worldwide now are overweight; and of those, more than 400 million are clinically obese.
- In China, obesity rose a staggering 97 percent in a ten-year period from 1992 to 2002 as 60 million people became clinically obese. Pediatric obesity in China is at 10 percent, and that number has been increasing by eight percent per year.
- In the US, obesity is up 50 percent from just one decade ago. Americans are among the fattest people on the globe, with two out of three adults overweight.
Obviously, something other than DNA is at play. WHO blames the obesity epidemic on "increased consumption of more energy-dense, nutrient-poor foods with high levels of sugar and saturated fats, combined with reduced physical activity." You don't have to be a brain surgeon to see the logic in that conclusion. As countries worldwide adopt the fast-food American diet and lifestyle, their citizens develop larger waistlines.
In 2006 alone, the fast food market grew by 4.8% internationally. In India, the fast food market is growing by 40 percent annually. In China, McDonald's, KFC, and Krispy Kreme all are wildly popular. The Moscow McDonald's is the world's busiest. And the portions in these places are between two to five times larger than two decades ago, all over the world.
We're eating more, and we're eating more of the wrong foods. The more accustomed we become to eating big portions of fun foods, the more difficult dieting becomes. The demarcation between normal eating and a "diet' becomes so radical that very few can sustain a diet of any sort, which may be why 99% of all diets fail.
So back to the genetics question. Melinda Sothern, an exercise physiologist at the University of Louisiana says that children, "are born with a certain number of genes they inherit, and then during their development, they have genes that will either turn on or turn off depending upon their environment and depending upon what behaviors they are allowed to participate in." Which brings us back to the caveat I mentioned earlier.
It seems the genetic predisposition to obesity may not manifest unless factors that we are in control of trigger it first. When parents ensure that their young children exercise and eat healthy foods in modest portions, they may literally prevent the fat genes from "turning on". But once kids grow into adults with poor eating and lifestyle habits, once those obesity genes have switched on, the process of losing weight becomes far more difficult. Bottom line: although genes may matter, eating and exercise habits matter even more.