Could diet drinks make you gain weight?

Diet drinks and meals may actually cause you to gain weight rather than lose it, according to a study published in Current Biology [1].

Researchers at Yale University have found that low calorie drinks which have a ‘mismatch’ in sweet taste and calorie count confuse the brain into craving more calories.

Sweetness typically signals a high calorie count and high energy levels to the brain. Therefore the body has evolved to burn more calories if something tastes sweet as it contains more energy and calories.

However, diet products which are too sweet or are not sweet enough for their calorie count can confuse the bodies’ metabolism. Diet drinks which do not taste sweet as relative to their calorie count trick the brain into thinking that there are fewer calories to burn. This may causes a decrease in the bodies metabolism, resulting in these remaining calories being stored as fat or muscle and leaving the body craving more food.

The study scanned the brains of 15 participants who consumed “diet” and “regular” drinks over a 5 day period and found that the body did not register how many calories it was consuming due to a mismatch in calorie count and sweetness in taste, which of course could lead to individuals eating more.

This study suggests that calorie count alone does not trigger our bodies metabolism as perviously assumed, but in fact is a combination of both sweet taste perception and calorie count.

[1] http://www.cell.com/current-biology/fulltext/S0960-9822(17)30876-X