A new study has found that fructose changes certain mechanisms in the brain that make us feel full after a meal which in turn leads to overeating and eventually weight gain.

The study was conducted by Dr. Kathleen A. Page and colleagues from Yale University School of Medicine. Researchers found that "ingestion of glucose but not fructose reduced cerebral blood flow and activity in brain regions that regulate appetite, and ingestion of glucose but not fructose produced increased ratings of satiety and fullness."

Fructose, commonly known as fruit sugar, is preferred over other types of sugars in the food industry because it is cheap and sweeter. Consumption of fructose in large amounts has been associated with obesity. Previous research says that high fructose corn syrup added in food leads to overconsumption of calories.

The study included 20 healthy adult volunteers whose brain scans were taken when they drank beverages containing either glucose or fructose. Researchers were trying to find out if there were any appetite-related changes in blood flow in the hypothalamic region of the brain.

Brain scans showed that glucose was associated with satiety while fructose increased hunger.

"Increases in fructose consumption have paralleled the increasing prevalence of obesity, and high-fructose diets are thought to promote weight gain and insulin resistance. Fructose ingestion produces smaller increases in circulating satiety hormones compared with glucose ingestion, and central administration of fructose provokes feeding in rodents, whereas centrally administered glucose promotes satiety. Thus, fructose possibly increases food-seeking behavior and increases food intake," according to background information in the article.

The study findings support the idea that "when the human brain is exposed to fructose, neurobiological pathways involved in appetite regulation are modulated, thereby promoting increased food intake," write Jonathan Q. Purnell, M.D., and Damien A. Fair, PA-C, Ph.D., of Oregon Health & Science University, Portland in an accompanying editorial.

The study is published in the Journal of the American Medical Association.