An apple a day keeps the doctor away, but it may not do much help you put the fork down. In a new study scientists have found why you may feel emptiness in your stomach even after eating a fruit salad.
Scientists found that the naturally occurring sugar in fruit, fructose, leaves people feeling hungrier and wanting more food. For the study, researchers asked 24 volunteers to view images of high calorie foods and non-food items while ingesting either fructose or glucose. They were then asked to rate their hunger and desire for food.
Researchers found that those who had ingested fructose had greater hunger levels and a desire for food compared to those who ingested glucose. The researchers said the findings suggest that "ingestion of fructose relative to glucose results in greater activation of brain regions involved in attention and reward processing and may promote feeding behavior."
'We gave the volunteers the choice between being served tasty food immediately after the study, or having money sent to them one month later. When the study participants consumed fructose, they had a greater willingness to give up the money to obtain immediate high-calorie foods, compared to when they consumed glucose," assistant professor of medicine at the Kreck School of Medicine, Kathleen Page says.
Researchers all took brain scans and blood tests of the participants that allowed them to see the affect it had on the brain as well as view the different hormones that control appetite.
"This allowed us to see how consuming fructose compared to how glucose affected the brain, hormone and hunger response."
Fructose is commonly found in both fruits and vegetables, while glucose is known as blood sugar and can be found in major carbohydrates such as starch. Although fructose and glucose both have the same amount of calories, the body processes each one very differently.
Cells in the body regulate the amount of glucose found in order to make energy, but fructose is metabolized in the liver and causes seven times as much cell damage as glucose.
Fructose is often used as sweeteners, leading many researchers to believe that the increasing levels of fructose in our diets could be yet another contributing factor to the growing levels of obesity in the world. "Obesity is a major public health problem, and increases in the consumption of fructose may be an important contributor to the current obesity epidemic," Page says.
Researchers recommend reducing the amount of fructose you consume to about 15 g per day. "The best way to reduce fructose intake is to decrease the consumption of added sugar sweeteners, which are the main source of fructose in the American diet."
