And suggests why sodas make us gain so much weight.

By Gillie Houston
Updated May 24, 2017
Phantom Diet
Credit: © Felix Oberhage / Getty Images

The latest diet fad to hit the Internet claims to help you lose weight by tricking the body into feeling fuller than it actually is. In a report titled "Empty calories and phantom fullness" in the American Journal of Clinical Nutrition, a group of Dutch researchers found it was possible to pull off this trick by increasing the viscosity—or thickness—of a food.

The small-scale study set out to test the theory that one's satisfaction with a meal is often directly correlated to their level of fullness following it, and to determine if there was a way to mimic the feeling of being fuller without added calories. To test this, researchers gave 15 men milkshakes with two different levels of thickness.

Results were dramatic: A thick milkshake containing just 100 calories made participants feel fuller than a thinner shake containing 500 calories. After drinking the shakes, the participants ranked their fullness level after 40 minutes; the higher-calorie shake's score was 48 out of 100, in comparison to the low-calorie shake, which had a response of 58 out of 100.

"Our results show that the viscosity is less effective than increasing the energy density in slowing gastric emptying. However, the viscosity is more important to increase the perceived fullness," the authors, who labeled this sensation "phantom fullness," wrote.

Though this study had a very limited test group, the researchers hope that their data will underscore just how bad it is to drink sugary sodas—not only are they calorically dense, they're physically thin. Maybe Coke should introduce a shake.