A recent study found that people who consume caffeine regularly tend to need a sweet snack after. This can be easily explained by the fact the widely consumed stimulant tempers the taste buds temporarily and that makes food seem less sweet that it is in reality. More exactly, caffeinated beverages change the perception of taste.
Caffeine is a powerful substance that is able to stop certain receptors, like the adenosine receptor that is responsible for the feeling of sleepiness, drowsiness and relaxation. Suppressing these receptors makes people more active and alert, but decreases the ability to taste sweetness, which usually makes the body crave more.
Robin Dando, who is an assistant professor at Cornell University in the US, explains that when an individual eats food directly after drinking caffeinated beverages, they will likely perceive food’s taste differently. The study was published in the Journal of Food Science and it included one group sampling decaffeinated coffee with 200 milligrams of caffeine added in a laboratory environment, making a strong cup of coffee. Then, the stimulant was added to make that group’s coffee consistent with real-life levels of caffeine.
The other group who took part in the study simply drank decaffeinated coffee, but both groups had sugar added. Participants who drank the caffeinated drink described it as less sweet.
In the second part of the study, the participants described their levels of alertness and approximated the amount of caffeine in their drink. They reported the same increase in alertness after drinking either the decaffeinated or caffeinated samples, while the panelists were not able to predict if they consumed the caffeinated version.
Dando suggested that people think it might be a placebo effect or a conditioning one, and that the caffeine is usually followed by alertness; panelists felt alert even if the caffeine was missing. He adds that the important fact is the action of drinking the coffee itself, because just thinking the person did something to feel more alert will determine them to feel more alert.