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Oatmeal is a near-universally beloved breakfast. While it has historically been enjoyed across Europe, Russia and the U.S., oatmeal is rapidly gaining popularity in developing countries because of its affordability and its perceived health properties. But is oatmeal really good for you?

To answer that question, it’s first important to differentiate among all the different types of oatmeal. There’s steel-cut and rolled, quick-cooking and instant. But all of these terms refer to different methods of preparing hulled oats for cooking.

“You can’t eat an unprocessed oat straight from the field,” says Joanne Slavin, a professor of food science and nutrition at the University of Minnesota. Harvested oats are wrapped in a hard husk that must be removed before cooking and consumption, Slavin says. When that husk removal is done, what’s left is the oat’s groat—which is its entire bran, endosperm and germ, the three components that constitute a whole grain. You can buy and cook whole oat groats. But all other types of oatmeal involve some type of processing to facilitate cooking.

Rolled oats, for example, are simply groats that have been steamed and smashed flat. Quick-cooking and instant oatmeal are typically rolled oats that have been further flattened, steamed or precooked to cut down on prep time. Steel-cut oats are groats that have been sliced up into small pieces instead of being rolled. But regardless of which you choose, Slavin says all types of oatmeal are considered whole grains, and all should be more or less equal in terms of their basic nutritional properties.

In other words, all kinds of oatmeal are healthy, experts say—with some caveats.

“Based on the existing evidence, eating whole grain oats is definitely good for our health,” says Shengmin Sang, a professor of food science and human health at North Carolina A&T State University who has examined the nutritional properties of oats. “Eating whole grain oats can prevent diabetes and lower cholesterol levels, which could prevent cardiovascular disease.” Some studies show that oats have anti-inflammatory effects, Sang says, “which could prevent inflammation related to chronic disease.”

Fiber is oatmeal’s main health attribute. “Fiber is good for so many things throughout the digestive tract,” Slavin says. In the stomach and small intestine, for example, fiber helps slow down food processing and absorption in ways that promote fullness and mellow the body’s insulin response. All that could reduce a person’s risks for Type 2 diabetes and metabolic disease, she says. Move farther along into the large intestine, and fiber feeds beneficial gut bacteria and promotes healthy stool, she says.

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And unlike wheat and most other grains, oats contain large amounts of a specific type of fiber called beta glucan, which studies have consistently linked to healthier cholesterol scores and a reduced risk for diabetes and cardiovascular disease.

But oatmeal’s health attributes extend beyond fiber. “There’s now increasing evidence showing that whole grain oats contain many phytochemicals, meaning plant-made small molecule compounds, that may have antioxidant and anti-inflammatory effects,” Sang says. He points to one particular oat phytochemical—called avenanthramide—as a promising inflammation fighter.

Oats are also an excellent source of B vitamins, vitamin E and minerals such as magnesium, says Edward Giovannucci, a professor of nutrition at Harvard School of Public Health. But he warns that loading oatmeal up with sugar, sodium or other additives can quickly diminish or offset its health benefits—a warning voiced by other experts. “Instant has all the whole grain components, but my concern is the sugar added,” Sang says.

And while oats are naturally gluten free, cross-contamination with other grains can potentially expose people to gluten. That’s concerning for those with celiac disease or gluten sensitivities. “Oats can be contaminated with gluten containing kernels of wheat, barley and rye at the field, during storage or during transportation,” says Ronald Fritz, an R&D scientist for PepsiCo (the company that owns Quaker Oats), who has researched the risks of gluten contamination in oatmeal. Fritz argues that Quaker employs technology to scrub its oats of gluten. But it’s not clear just how often oatmeal products are contaminated, or how consumers can reliably avoid this issue apart from relying on producers to ensure their products are gluten-free.

Those concerns aside, pretty much everyone agrees that eating oatmeal—assuming you’re opting for a type free of sugar and other unhealthy additives—is a good idea. “Whole grains are beneficial and healthy foods, and I can say that oatmeal is definitely beneficial,” says Qi Sun, an assistant professor of nutrition at Harvard, citing both his past research on whole grains and also some soon-to-be-published work he’s done on oatmeal. “Eating oatmeal for breakfast is a good choice.”

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