LONDON - Want to lose weight? Try eating. That's one of the strategies being developed by scientists experimenting with foods that trick the body into feeling full.
At the Institute of Food Research in Norwich, England, food expert Peter Wilde and colleagues are developing foods that slow down the digestive system, which then triggers a signal to the brain that suppresses appetite.
"That fools you into thinking you've eaten far too much when you really haven't," said Wilde. From his studies on fat digestion, he said it should be possible to make foods, from bread to yogurts, that make it easier to diet.
While the research is preliminary, Wilde's approach to curbing appetite is one that some doctors say could be key in combating the obesity epidemic.
"Being able to switch off appetite would be a big help for people having trouble losing weight," said Steve Bloom, a professor of investigative medicine at London's Imperial College, who is not connected to Wilde's research.
Scientists in North America and elsewhere in Europe are also trying to control appetite, including through chemical injections or implantable devices that interfere with the digestive system.
Bloom said that regulating appetite through modified foods is theoretically possible. Other mechanisms in the body, like cholesterol production, are already routinely tweaked with medicines.
But Bloom warned that controlling appetite may be more challenging. "The body has lots of things to prevent its regulatory mechanisms from being tricked," he said.
For instance, while certain hormones regulate appetite, the brain also relies on nerve receptors in the stomach to detect the presence of food and tell it when the stomach is full.
Wilde's research hinges on the body's mechanisms for digesting fat.
Fat normally gets broken down in the first part of the small intestines. When you eat a high-fat meal, however, the body can only digest the fat entirely further down in the intestines. That sparks a release of hormones that suppress appetite.
Wilde's approach copies what happens with a high-fat meal: He coats fat droplets in foods with modified proteins from plants, so it takes longer for the enzymes that break down fat to reach it.
That means that the fat isn't digested until it hits the far reaches of the intestines. At that point, intestinal cells send a signal telling the brain it's full.
Even though the body hasn't had a high-fat meal, it suppresses the appetite as if it has. If the fat had been digested earlier in the intestines, no such signal would be sent.
Wilde said the technique should work with any foods that contain fat, like dairy products, precooked sauces, mayonnaise, breads and pastries, and that taste would probably not be affected.
If all goes well, products could be on shelves within a few years, he said.
In another technique, scientists at the University of Newcastle have been testing a seaweed extract called alginate that reduces fat absorption by cutting the level of glucose digested by the body before it gets broken down in the large intestine.