The physical form of food alters carbohydrate absorption. Rolled oats, for example, have a significantly lower glycemic index than instant oatmeal, which is just oats, but in thinner flakes, and oat flakes cause lower blood sugar and insulin spikes than powdered oats. Indeed, the same single ingredient–oats, in this case–can have different effects in its different forms.
Why do we care? Well, the overly rapid absorption of carbohydrates after eating a high-glycemic index meal can trigger a sequence of hormonal and metabolic changes that may promote excessive eating. Researchers fed a dozen obese teen boys different meals, each with the same number of calories, and followed them for the next five hours to measure their subsequent food intake. Those who ate the instant oatmeal went on to eat 53 percent more than the boys who ate the same number of calories of steel-cut oatmeal. The instant oatmeal group was snacking within an hour after the meal and went on to consume significantly more calories throughout the rest of the day. Same food but different forms had different effects.
It’s crazy how the same product can have such different effects on the body, based on how it’s processed. Beyond focusing just on whole rather than refined grains, the wholiest of all are intact grains. Instant oats are better than powdered oats, rolled oats are better than instant, steel-cut oats are better than rolled, and intact oat groats are the best of all!
For more information on the effects of food structure, watch this video.
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