What Type of Oats is Best? Quick Oats vs Old Fashioned Oats vs Steel Cut Oats

If you are trying to improve the quality of your breakfast, you may wonder which is better: quick oats vs old fashioned oats vs steel cut oats. What is the difference between these types of oatmeal? Which one should you eat?

Oatmeal Production and Processing

The differences between the types of oats is due to the processing. They all start the same way though. After the oat grains are cleaned, they are dehulled to remove the husk. Inside is the oat groat. What happens next with the oat groat is what determines what type of oat will result.

Steel Cut Oats

Steel cut oats are the oat product that most closely visually resembles the oat groat. With steel cut oats, the groat is merely cut into two or three pieces. Because the final product is larger and less processed when the consumer purchases it, it requires the longest cooking time of around 20 minutes.

Old Fashioned Oats

Old fashioned oats are also known as rolled oats. The name describes the processing. These oats are steamed and processed through rollers that flatten the groat. Finally, they are lightly toasted to stabilize the grain. Because they are processed into smaller pieces than steel cut oats and are steamed, they cook faster than steel cut oats in about five minutes.

Quick Oats

Quick oats are groats that are chopped into smaller pieces before being steamed, processed through rollers, and lightly toasted. They are similar to old fashioned oats in their production, but because the resulting oats are smaller than old fashioned oats, they cook faster. Quick oats take about one minute to cook.

Quick Oats vs Old Fashioned Oats vs Steel Cut Oats: Factors to Consider

The common assumption is that steel cut oats must be the healthiest because they are the least processed. With most foods, the less processed it is, the healthier. This is because processing usually adds ingredients that do not add to the nutritional quality of the food. Traditionally, processing adds salt, sugar, or saturated fat. With oats, the main difference is how small the oats are cut or rolled. Quick oats, old fashioned oats, and steel cut oats do not have added ingredients.

Another factor to consider, given the size of the individual oat pieces, is how they are measured when compared. If you start with 1/2 cup of each variety of oats, you will not have exactly the same amount of each variety because of differences in how tightly packed the grain is in the cup. To make an accurate comparison, it is important to compare based on weight not volume.

Examining Food Labels: Quick Oats vs Old Fashioned Oats vs Steel Cut Oats

When comparing these three types of oats of the same weight, they seem identical in nutrient content. Per the nutrition facts labels available on Quaker Oats' website, there are 40gm of oats in each 1/2 cup quick oats, 1/2 cup old fashioned oats, and 1/4 cup steel cut oats. Each of these 40gm servings contains 150 calories, 27gm carbs, 4gm fiber, and 5gm protein. My assumption is that Quaker rounds slightly with the grams that they say are in each of the serving sizes because when I weighed their specified serving sizes, I got slightly different values. Slight variations are not practically significant, and are within what is allowed with food label regulations.

Bob's Red Mill's nutrition facts seem to provide more precise numbers for the weight of their serving size. The grams in their 1/2 cup servings of quick oats and old fashioned and 1/4 cup serving of steel cut oats vary slightly, in the 44-48gm per serving range, presumably due to the slightly differing densities of the different varieties. There are 1gm differences in fiber and protein content per serving between the varieties, though when the math is computed to find grams of protein and fiber per 40gm oats, they were all equal, with the values being identical to those of Quaker Oats'.

What I Heard from a Quaker Oats Representative

I called Quaker Oats to confirm this. The representative told me that the same type of groats are used for all three varieties of oatmeal. The only difference is in how much the oats are cut or rolled. Nothing is removed from the groat or added to the product in any of these three varieties.

What I heard from a Bob's Red Mill Representative

I had a much longer discussion with the Bob's Red Mill Representative. Their blog post states about the differences in nutrition between the varieties that "the differences lie in the dietary fiber content of steel cut oats...steel cut oats provide 5g of fiber per 1/4 cup serving of dry oats, which is about double the amount of fiber you can get from rolled oats." In my discussion with the representative, I asked if that was just due to the differing grams of oat that fit in 1/4 cup steel cut oats compared to 1/4 cup of the other varieties. After a bit of a roundabout discussion, the conclusion was that while there might be slight variations in the nutrient content of all varieties from year to year given differences in growing conditions, essentially, gram for gram, all varieties have equal amounts of protein and fiber.

He did mention the idea that digestion may be different for the three types oats. Logically, this makes sense. The steel cut oats are the most intact when you buy them, the quick oats are the least intact, and the old fashioned oats fall in the middle. These differences mean differing surface areas for our digestive enzymes to work on. Theoretically, the quick oats should be digested the fastest, the steel cut oats the slowest, and the old fashioned oats digested at a speed between the other two. This should lead to a higher initial rise in blood sugar with the quick oats, a lower initial rise in blood sugar the old fashioned oats, and the lowest initial rise with the steel cut oats.

What do the data say?

Indeed, the one study that I could find, published in 2019, confirms this hypothesis. This study compared steel cut oats, old fashioned oats and instant oats (not quick oats.) For peak rise of blood glucose, the steel cut oats had the lowest value, the old fashioned oats had the middle value, and the instant oats had the highest value. The steel cut oats were also superior in a measure of insulin response.

Bottom line: Quick Oats vs Old Fashioned Oats vs Steel Cut Oats

My most important takeaway is how similar the three varieties are. They are identical in fiber and protein content when you compare them gram for gram. They are all very nutritious foods that can be part of a healthy pattern of eating.

For some people, such as those with diabetes, it can be somewhat helpful to understand that there are some differences in glycemic response between the types of oats. Published glycemic index values show a higher glycemic index for quick oats, then old fashioned oats follows, and then last is steel cut oats with the lowest glycemic index. I qualified that comment as "somewhat helpful to understand," because glycemic response is greatly impacted by foods eaten in combination with the specified food. In general, combining any carbohydrate food with fat, such as adding nuts to oatmeal, will blunt the rise in blood glucose.

I think that there are other important factors to consider when choosing which oats to eat. First is taste preference. Which one do you enjoy more? Which flavor and texture do you like? Second is time constraints. Quick oats are, of course, quick to prepare in one minute, old fashioned oats take five minutes, while steel cut oats take around 20 minutes to cook. Third is cost. With some brands, steel cut oats cost more. The packages of steel cut oats are often smaller than the packages of the other varieties, so while the cost for the package may be lower, the cost per serving can be higher.

When choosing a type of oats, you have a good "problem." You have to choose between three nutritious options. They are all great breakfast foods that will help you stay full. They are also high in fiber, specifically beta glucan that is great for lowering cholesterol, and they have plenty vitamins and minerals. My personal favorite for taste and texture is steel cut oats, but my usual go to, due to morning time constraints, is old fashioned oats.

Final Thoughts

When we talk about nutrition and healthiness of a food, sometimes we are missing the larger picture. There may be differences between different products, but sometimes those differences are small and not important in a practical meal planning sense. Overall quality of an eating pattern is important. A meal's entire composition is more useful to evaluate than any particular food on its own. A meal that contains a variety of macronutrients usually leads to greater satiety than eating a single macronutrient. Combinations of food are often more pleasurable and palatable than single foods on their own. We are humans eating food, not computers picking an item based on a single criterion.