Researchers split 36 men and women into 3 different groups: One group ate oatmeal for breakfast, another ate corn flakes, and the third group skipped the meal altogether. Throughout the next 3 hours, study participants were asked several times to rate how hungry they felt, and they also gave blood samples to track their levels of glucose and insulin. Then they were given a liquid lunch and told to drink until they felt full. Just as researchers had predicted, the people who ate oatmeal were less hungry throughout the morning and ate about 31% fewer calories at lunch—despite being given the same number of calories at breakfast as the corn flakes group, says study author Allan Geliebter, PhD, a research psychologist at Mount Sinai St. Luke’s Hospital in New York. So what was keeping the oatmeal-eaters full? Their breakfast stayed in their stomachs longer. Here’s how they know: Researchers added acetaminophen—yes, the same thing you take when you have a headache—to the cereal bowls and measured it in the blood; by tracing it, they could see how long the acetaminophen (and with it, the food) stayed in participants’ stomachs. “We found that acetaminophen levels peaked for the oatmeal group much later than they did for the other groups,” says Geliebter. “That tells us the oatmeal stayed in the stomach longer, most likely because of its high fiber content.” So, oatmeal keeps you full—that much we sort of already knew. But what the researchers did find surprising was that the people who ate cereal for breakfast consumed just as many calories at lunch as the people who hadn’t eaten a thing. That’s probably because the cold cereal caused their blood sugar to spike very quickly—then drop just as quickly, says Geliebter. And by the time lunch rolled around, that group’s low blood sugar left them famished. And if all that doesn’t inspire you to give oatmeal a try tomorrow morning, this gingersnap oatmeal recipe certainly will. MORE: 5 Ways To Make Oatmeal Exciting
