Looking at pictures of tasty foods increases a hormone that regulates eating behavior and physical processes involved in food metabolism and can heighten inaccurate perceptions of hunger, scientists said Thursday.

Researchers said in a released statment on Thursday that for the first time, they have managed to scientifically prove what people have generally thought, that the “mere sight of delicious food stimulates the appetite."

Researchers from the Max Planck Institute of Psychiatry investigated the molecular processes for the control of food consumption by examining the levels of different hormone concentrations in the blood of healthy male participants that regulate food consumption like ghrelin, leptin and insulin when exposed to images of food or non-edible objects.   

Researchers found that the concentration of ghrelin, a hormone in charge of stimulating hunger and which increases in levels before meals and decreases after meals, increased significantly in the blood stream as a response to visual stimulation with food images. 

"The findings of our study demonstrate, for the first time, that the release of ghrelin into the blood for the regulation of food consumption is also controlled by external factors. Our brain thereby processes these visual stimuli, and the physical processes that control our perception of appetite are triggered involuntarily. This mechanism could prompt us to eat a piece of cake just two hours after breakfast," said Petra Schüssler, a scientist at the Max Planck Institute in a statement.

Researchers said while physiological mechanisms are responsible for maintaining the body's energy status, environmental factors may also have a specific influence on food consumption.

“The danger that the exposure to such images will result in the consumption of food that is not needed to maintain the body's energy status is particularly high in our advertising-dominated society,” researchers wrote.

Schüssler recommended that individuals with weight problems should avoid looking at images of appetizing food.