One of the big dieting tips touted lately is to eat less of foods with fructose in them. Fructose is a sugar that occurs naturally in fruits and some vegetables, but the source people are worried about is fructose in sugar—"table" sugar, aka sucrose, is half fructose, half glucose (glucose is the carbohydrate found in non-sweet starches like potatoes and grains).
A relatively small but vocal group of researchers believe that fructose is the main cause of obesity, metabolic syndrome, and maybe even heart disease. They say that fructose has these evil effects because the way the liver metabolizes fructose leads it to be stored as fat.
But a new study conducted at Yale University Medical School discovered another possible reason fructose may cause weight gain: Eating it fails to activate the brain's centers that signal satiety and fullness. In the study, 20 healthy adult subjects underwent two MRIs, one after consuming fructose, the other after consuming glucose. The researchers found that eating glucose lead to reduced blood flow to regions of the brain that regulate appetite, motivation and reward processing, and that consuming glucose led to sensations of satiety. On the other hand, when the volunteers ate fructose there was no reduced brain activity in appetite-related areas of the brain, and no increased satiety.
The study was published in the latest Journal of the American Medical Association, and an accompanying editorial concluded:
These findings support the conceptual framework that when the human brain is exposed to fructose, neurobiological pathways involved in appetite regulation are modulated, thereby promoting increased food intake" and that "… the implications of the study . . . as well as the mounting evidence from epidemiologic, metabolic feeding, and animal studies, are that the advances in food processing and economic forces leading to increased intake of added sugar and accompanying fructose in U.S. society are indeed extending the supersizing concept to the population's collective waistlines."
So if you're one of the many Americans hoping to lose weight in 2013, eating fewer foods with fructose might be one of the best dieting tips you can follow. Keep in mind that while fructose is found naturally in fruit, fruit is also packed with fiber and vitamins so nobody is saying you should stop eating it. What you should cut back on is fructose in sugar—and it's found in all sugar, including table sugar, high fructose corn syrup, and any of the many names sugar goes by in processed foods.
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