Serve people more food and they'll eat more. But does the size of each food item or the number of items matter most?

In a recent study, researchers offered 186 people a plate of brownies to eat while watching a video. Each plate held 1, 2, 4, or 8 brownie squares in one of three sizes: ¼ oz., ½ oz., or 1 oz.

Overall, people tended to eat more when the plate held a smaller number of large brownies than when it held a larger number of small brownies. For example, 60 percent of the participants ate two 1 oz. brownies, but only 40 percent ate four ½ oz. brownies and a mere 18 percent ate eight ¼ oz. brownies (even though each of the three plates held 2 oz. of brownies).

What to do

Want to eat less? Stick with smaller-size items.

Photo: Kaamilah Mitchell/CSPI.