I was recently asked the question what is better, steel-cut oats or rolled oats? I had heard in the past that steel-cut oats are “better” for you and can help with fat loss. Why is that? Let’s take a deeper look at what the difference is between the two.
If you look at the difference between the fiber content, carbohydrate content, and protein content, each is relatively about the same. A typical serving of oats is typically 1/4 cup dry of rolled, 2 – 2 1/2 tbsps steel cut and contains 80 calories, 15 g carbohydrates, and about 3 g protein.1 Fiber is the main component that is responsible for keeping blood sugar regulated by slowing down the release of blood glucose into the bloodstream. In this manner, the insulin response is not going to be as great as say a piece of white bread or refined pasta. Lack of fiber increases luminal uptake of the starches, therefore insulin spikes and blood glucose spikes. With this question in mind, why would there be a difference if the composition is the same? It has to do with the processing.
There are three different types of oats: quick oats, rolled oats, and steel-cut oats. Each oat starts out as a groat. This groat is further heated at low temperatures to kill any enzymes to prevent rancidity. These groats are either cut into small pieces(steel cut) or are further processed to produce rolled oats and quick oats. Both rolled oats and quick oats are milled yet the latter is processed thinner. Further processing of the oat not only changes the texture and may affect luminal uptake of the starches.2 How may this affect the insulin response?
According to a recent study assessing the glycemic response between the three, steel-cut oats showed the lowest rate of starch digestion while quick oats showed a higher rate. This response may be attributed to the presence of Beta Glucan increasing viscosity of the food and reducing the postprandial, or post eating, glucose response. The authors theorized that alterations in the sugars during the processing of the oats could be the culprit.3 This may be of great importance to the fitness community, especially those looking to lose weight. Insulin plays a role not only in satiety but in adipogenesis, or the production of fat cells. Decreasing the insulin response will ultimately be more beneficial if fat loss is the goal of the individual.
Therefore, as far as the average Joe, rolled oats and steel-cut oats could be used interchangeably. If glucose regulation is intended, I would lean towards the steel cut oats as they are more in their whole form.
References:
1.Evert, A. et. al. Food Lists For Weight Management. Academy of Nutrition and Dietetics. 2019.
2.Foster, K. What’s the Difference Between Steel-Cut, Rolled and Instant Oats. Ktchn Website. 2015. https://www.thekitchn.com/whats-the-difference-between-steel-cut-rolled-and-instant-oats-138355. Accessed January 14, 2021.
3.A, Fatemah, M, Rogers. In vitro measurements of luminal viscosity and glucose/maltose bioaccessibility for oat bran, instant oats, and steel-cut oats. 2017. Food Hydrocolloids Abstract retrieved from https://www.sciencedirect.com/science/article/pii/S0268005X17306458?via%3Dihub.
