Surprise: Super-Thick Foods Will Make You Feel Full

A buddy of mine once tried one of those insane eating challenges that involved housing a one-and-a-half pound deli sandwich and a six-pound milkshake. He failed miserably, but it wasn't the sandwich that did him in. He made a decent dent on that, but he barely got through a fifth of the super-thick vanilla milkshake. (Vanilla, really?)

Even though hundreds of other people were able to take down both—including the Man vs. Food guy—science was against him finishing the challenge. New research shows that thick foods induce feelings of fullness, regardless of their caloric density. And with that high-fat, high-sugar milkshake, poor old Landry was fighting a two-front battle.

A team from the Wageningen University and Research Center and the University Medical Center Utrecht in the Netherlands recently published a study in The American Journal of Clinical Nutrition that found that thicker foods create feelings of "phantom fullness." When study participants drank both thickened and comparably thinner milkshakes, a thickened 100-calorie milkshake led to greater perceived fullness than a thin, 500-calorie milkshake.

"The increase in perceived fullness that is due solely to the increased viscosity, which is a phenomenon that we refer to as phantom fullness, may be useful in lowering energy intake," the study said.

The research team wasn't looking for a new breakthrough healthy diet—they were studying how quickly foods of different viscosities exit the gastric system—but their findings raise interesting possibilities for people trying to lose weight. However, it isn't entirely clear what kinds of foods might make you feel full while cutting down calorie intake.

"Honest answer is: we don't know, as we only performed the experiment with one type of thickener (locust bean gum)," study author Guido Camps, a researcher at Wageningen University and Research Center, told MUNCHIES by email. "However, if this works in the way we think it works, these foods would be types of foods which are relatively low in calories but require more effort to eat."

Camps suggests adding fiber to foods to try to thicken them up, since that's what worked for them and most people don't have enough fiber in their diets anyway. But, he says, it's "really a bridge too far with the current results" to say whether phantom fullness could be useful for someone trying to lose weight.

Alas, switching to a thick milkshake diet for health reasons probably isn't in the cards.

"I wouldn't advise it. However, try thickening your fruit smoothie and see if you feel more full," Camps said.