WHACK!! My hand slammed the top of the alarm clock to stop the repetitive screeching. Ouch! I realized I hit the snooze button too hard as I felt a dull ache in the palm of my hand. At least I didn’t knock the alarm clock completely off the top bunk bed without pressing snooze like I did last week. I had since decided to wrap the alarm clock cord around the top bars of the bunkbed. I let my eyes adjust to the darkness for a minute before I slid down the ladder. I took off my favorite pajama shirt, a picture of a frog choking a heron as it was being swallowed, with the caption “Don’t EVER give up.” I put on a white undershirt and some socks, glancing over at my brother who was still asleep on the bottom bunk.
As I pulled the bedroom door open, I carefully lifted up on the doorknob to prevent the bottom of the door dragging on the carpet. The door alignment was off due to the mini basketball hoop that hung over the top of the door. As I stepped into the hallway, I saw a framed picture propped on the carpet. “Huh,” I thought, I guess it fell off the wall. I glanced at the picture briefly. It displayed my great uncle, a World War II bombardier, standing with his crew in front of their aircraft. I placed the picture frame back on its nail so it could cover up the hole one of my other brothers had punched in the wall.
I crept down the stairs, careful to avoid the steps that creaked the loudest, especially the third one from the bottom. I dimmed on the lights as I walked into the kitchen. I walked straight over to the living room TV, knelt down and pushed the power button. I quickly moved my finger two buttons over to “volume down” and held it until the volume was at zero. The time flashed on the upper right corner of the TV in bright blue numbers, 5:54AM. One minute later than usual. That gave me six minutes to make my breakfast and get back to the couch before Pokemon started. I went back into the kitchen and brought a china bowl decorated with apples and green leaves from the pantry over to the kitchen sink. I ran the water for 10-15 seconds until it got warm, but not scalding hot. I placed the bowl under the running water and let the water rise until it reached the bottom of the first apple. Then I poured in a packet of cinnamon and spice instant oatmeal and stirred it until the consistency was just right. I walked back to the TV, turned the volume up to six blue bars, sat on the couch under the covers, and enjoyed my oatmeal.
Some days the TV show was Looney Tunes or Beast Wars Transformers instead of Pokemon. Some days I ate maple and brown sugar oatmeal or apples and cinnamon oatmeal instead of cinnamon and spice oatmeal. On cold winter days I skipped the TV altogether and preferred to eat while sitting over a hot air vent on the floor. Occasionally, I substituted the oatmeal with Cinnamon Toast Crunch or Cheerios sprinkled with a little bit of sugar. But most often, my grade school weekday morning routine consisted of cartoons and Quaker Instant Oatmeal. At the time, I had no idea if the oatmeal was good for me or not. That wasn’t even on my radar. But it tasted good and it was quick.
If you live a typical American lifestyle, your weekday mornings may look something like this: You snooze your alarm clock a few too many times and by the time you wake up and get ready, you’re rushing to get out the door. Breakfast consists of whatever you can find in the pantry or freezer that you can make and eat in five minutes or less. If nothing fits the bill, you may stop through a drive-thru for a coffee and a breakfast sandwich, or you may skip breakfast altogether and eat a granola bar later in the morning.
Weekday mornings exemplify the hectic, fast-paced, too-much-to-do-in-too-little-time American lifestyle. They also exemplify how we prefer convenience foods over preparing our own food when we get busy. The problem is we feel busy all the time, so we eat convenience food all the time. In fact, the Bureau of Labor Statistics “American Time Use Survey” for 2017 shows that the average American spends twice as much time eating and drinking per day (70.8 minutes) as they do in food preparation AND cleanup (36 minutes)! The food industry is more than happy to prepare our food for us, and charge us much more than the cost of the ingredients, which is why convenience foods can be found at most grocery stores, gas stations, cafeterias, or even boxes delivered directly to your home. As long as we keep buying convenience foods, the food industry will keep selling them.
Right now, it doesn’t look like we plan on slowing down convenience food consumption anytime soon. Unfortunately, most convenience foods are heavily processed and unhealthy. A 2016 study in BMJ Open showed that Americans average 58% of their calories from “ultra-processed” food! This is how they defined “ultra-processed” food:
“Formulations of several ingredients which, besides salt, sugar, oils and fats, include food substances not used in culinary preparations, in particular, flavours, colours, sweeteners, emulsifiers and other additives used to imitate sensorial qualities of unprocessed or minimally processed foods and their culinary preparations or to disguise undesirable qualities of the final product”
Why are Americans eating over half their calories from the most unhealthy food options available? I think “convenience” summarizes a majority of the biggest reasons (especially cost and time). However, I think most Americans also underestimate the effect of food processing on nutrition. There are thousands of convenience foods marketed as “healthy,” but most of them aren’t. To help us begin understanding which convenience foods are actually healthy, I’m going to use a convenience food that America has eaten since the mid to late 1800s, processed oats.
As usual, a helpful way to understand the nutrition of oats is to visualize how they are made. Let’s start with this brief video on oat production:
Oats: Farm to Fork
https://www.youtube.com/watch?reload=9&v=D_hl5LEBIms
Let’s review some of the key features of oat anatomy and processing.
Basic Anatomy of an Oat
Husk: Outer fibrous protective layer which covers the entire seed, similar to a corn husk, not digestible by humans. Also called a “hull.”
Seed: This is what most people call an “oat,” but its technical name is an “oat groat.” It is a whole grain containing all three layers of a grain, the bran (outer coating that contains most of the fiber), endosperm (starchy energy source) and germ (the embryo, which can develop into a whole new plant).
Oat Processing
When oats are processed, the husk is removed from the oat groat by a machine called the de-huller. If the raw oat groat is eaten before it is processed any further, it may pass through the entire human gastrointestinal tract ‘unprocessed’ because the body’s digestive enzymes cannot penetrate the thick outer shell or the complex structure of the inner starch. After all, the whole point of the outer shell is to protect the seed from harm so that it can find a home in the ground and grow into a new plant. If the oat groat passes through the gastrointestinal tract unprocessed, the body will only get a tiny fraction of the potential nutrition from the oat groat. Some degree of food processing is actually required for human digestion and absorption of all of those beneficial nutrients and phytochemicals in oats.
After removal of the husk, commercial oat groats go through further processing, called kilning. A kiln is basically a type of oven that uses heat to induce chemical changes in the oat, somewhat similar to pasteurization of milk. The heat provided through kilning destroys bacteria, yeast and mold. It also inactivates enzymes native to the oat that may lead to spoiling. The oat, like most other plants, contains enzymes to digest its own energy source when it is time to grow into a new plant. The enzymes are separated from the energy source by little walls. Since the walls are destroyed during milling, the enzymes have free access to the energy source, leading to partial digestion which can cause food to spoil. Kilning inactivates the oat enzymes to prevent spoiling if the oat is later milled. Unfortunately, kilning destroys some heat-sensitive vitamins in the process. Overall, the benefits of kilning outweigh the loss of a few vitamins since it prevents spoiled or contaminated food, which would have to be discarded. Once again, food processing proves to be beneficial for health in this case.
The above chart found from a Decker, et al 2014 article helps summarize the key steps in oat processing. The non-digestible seed is the oat groat with the husk still on. “Heat” and “dry” represent the kilning process.
At this point, we have a kilned oat groat. It is still a whole grain and it is still very healthy for you. However, remember that an oat groat is a seed. It is quite hard and thus difficult to eat. Hence, most people cook it in a pot of boiling water to soften it. This simple form of cooking is actually another form of food processing called gelatinization, a fancy name for a change in the structure of starch molecules in the presence of heat and water. Starch is a long chain of carbohydrates. More specifically, a starch is a chain of 10 or more glucose molecules wound together in a clustered double helix, similar to the shape of DNA. The double helix is twisted and folded into a complicated structure and it rests in a type of protein jelly. When starches are heated in water to temperatures ranging from 115-160 degrees Farenheit, the clustered double helix of the starch begins to unwind, and water forms a hydrogen bond that stabilizes the structure of the double helix (Tester and Karkalas 1996). As water forms hydrogen bonds with the oat’s starch, the whole oat groat becomes much larger and softer due to the water it has absorbed. This swelling allows digestive enzymes to penetrate the complicated structure of starch and break it down. On the flip side, it also allows some of the nutrients that were previously locked tightly into the structure of the starch to escape into the cooking water. Yet again, this step of food processing is necessary for humans to eat and to digest these types of foods.
Adapted from Wang, et al 2017, this image demonstrates the degree of starch gelatinization (DG) and its effect on the ability of enzymes to break down starch.
So now we have a kilned, gelatinized oat groat, which is still 100% whole grain. As long as all the water is absorbed back into the oats during cooking, the oat groat still contains almost all of its healthy nutrients and phytochemicals. And finally, the oat groat has been processed enough that it can be eaten.
“Fill, I’ve never even heard of oat groats. Why can’t I buy them at the grocery store?”
If you search online, you can buy them in 25-50lb bulk bags from companies like Bob’s Red Mill or Honeyville. But these aren’t popular enough in the U.S. to be stocked on grocery store shelves. Why? Because they aren’t convenient and they take too long to gelatinize. So instead of being sold directly to the public as is, most kilned oat groats are further processed by cutting, flattening or grinding to decrease the amount of time it takes to gelatinize, or cook. If the oat groats are cut into two or four pieces, they are known as steel cut oats. If the oat groats or steel cut oats are flattened between two rollers, a process sometimes called flaking, they are called rolled oats. The thinner the oats are rolled, the faster they gelatinize. For example, instant oats are rolled thinner than regular or old-fashioned rolled oats. Oats can also be ground instead of cut or rolled. Coarsely ground oats (often called Scottish oats) are not common in the US. Finely ground oats are called oat flour.
(Decker, et al 2014)
“Fill, you’ve mentioned that all of the food processing steps so far actually help the human body access the nutrition of the oat groat. But what about cutting, flaking or grinding the oat groat? I’ve heard of arguments about the nutritional difference between steel cut oats and old-fashioned rolled oats. Is there a difference?”
Great question. Cutting, flaking and grinding represent the first unnecessary step of oat processing. These steps don’t significantly affect any nutrient information you see on a nutrition label, but they do affect how the body senses and processes the food. I like to think about this aspect of nutrition in terms of surface area. Let’s say the surface area of an intact, kilned oat groat is 1 unit. As the oat groat is processed, there is more surface area exposed. So if the oat groat is steel cut, the surface area increases to 1.5 units. If the oat groat is rolled into instant oats, the surface area increases to 4 units. If the oat groat is ground into flour, the surface area increases to 10 units. These aren’t precise numbers, but they provide an example to prove my point. As the surface area of the oat groat increases, it affects both food storage and digestion. Oats with a larger surface area are more susceptible to contamination, oxidative damage, and nutrient degradation during storage. Hence the shorter shelf life of oat flour compared to steel cut oats. During digestion, larger surface area exposes more of the oat groat to the body’s digestive enzymes, leading to quicker uptake of the nutrients into the bloodstream, which for some nutrients can be unhealthy. For example, instant oats raise blood sugar quicker and to a higher peak than steel cut oats.
“Fill, the idea of greater surface area being less nutritious makes sense to me. But I don’t measure the surface area of my foods. Is there a more practical way to determine this?”
Yes, the answer is a lot simpler than you think. You can estimate this just by looking at your food. For example, french fries are going to have far more surface area than the potato that they come from. Smoothies are going to have far more surface area than the fruits that they are made from. In general, the largest change in surface area for starchy foods occurs when they are ground down into flour.
“Okay, I think I see where you’re going with this Fill. You’re telling me that my beloved Honey Nut Cheerios (which are consistently among the most purchased breakfast cereals in American grocery stores every year) are made from oat flour, which has a very high surface area compared to the oat groat and that not even counting for the added sugar and other food additives, they aren’t good for me? The convenience of my ready to eat breakfast cereal is not convenient for my health.”
Ha, I sense some cynicism developing, but you may be starting to develop an appreciation for just how important food processing is to nutrition. “Whole Grain Oats” are the first ingredient on a Cheerios or Honey Nut Cheerios box, even though the first ingredient is really “Whole Grain Oat Flour.” Is this really still a whole grain? Let’s look at the formal definition of a whole grain to help us answer this question.
“Cereal grains that consist of the intact, ground, cracked or flaked caryopsis [you can substitute “seed” for caryopsis here], whose principal anatomical components – the starchy endosperm, germ and bran – are present in the same relative proportions as they exist in the intact caryopsis should be considered a whole grain food” (American Association of Cereal Chemists).
Whoa! So an intact oat groat, a ground oat groat (oat flour) and a flaked oat groat (steel cut or rolled oats) all count as whole grains? Yup. This is a bit confusing as it doesn’t seem like common sense to call flour a whole food. But the main purpose for this definition is to distinguish whole grains from refined grains, and their huge difference in nutritional value. Whole grains are generally deemed to be nutritious, while refined grains are generally deemed to be harmful to human health because the majority of healthy nutrients and phytochemicals are removed.
“Wow, Fill! I didn’t realize there was such a large difference in nutrition between whole and refined grains! I’m going to start substituting whole grain foods for refined grain foods in my pantry. But I’ve been thinking more about what you said about surface area and whole grains. If I don’t have problems with blood sugar, is there any other reason I should choose intact whole grains over whole grain flour products?”
That’s a very difficult question to answer because almost all scientific research uses the same definition for whole grains as that given by the American Association of Cereal Chemists, the Whole Grains Council, and the United States Food and Drug Administration, quoted above. The vast majority of scientific evidence to date states that whole grains are associated with health benefits, despite including foods made from whole grain flours as “whole grains.” It’s possible that if scientific studies split the “whole grains” category into “intact whole grains” and “whole grain flour products” that they may find a difference on human health. I’d love to see a metabolic ward study, research where food intake is very strictly controlled, comparing intact whole grains and whole grain flour products. But at this time, all we know with certainty about grains is that refined grains (grains with the bran and germ removed) are unhealthy for you, and that whole grains as defined above are healthy for you. That said, there are some important differences between intact whole grains and whole grain flour products that I would like to point out.
- Glycemic response
I know I mentioned this already, but since roughly 1 in 3 Americans have prediabetes or diabetes, this is worth mentioning again. Most products made from whole grain flour raise blood glucose faster and higher than the same intact whole grain. For example, Cheerios raise blood glucose faster and higher than the same amount of cooked oat groats. Even instant oats raise blood sugar faster and higher than the same amount of cooked oat groats. Of note, the surface area is only one of many factors that affect the rate and extent of glucose rise, or the glycemic response.
- Water content
When cooking intact oat groats or steel cut oats, the ratio of water to oats is usually 3:1 or 4:1. Most of that water is absorbed into the oats, which means the #1 ingredient in cooked oat groats or steel cut oats is water, a zero calorie food. Conversely, when oat groats are ground into flour, the ratio of water to flour in the final flour product may decrease to 1:1 or less.
- Caloric density
Due to the lower water content, many whole grain flour products, even products with minimal other ingredients like crackers and bread, have a higher calorie content per gram of food than the cooked intact whole grain. Given the higher caloric density, eating products like crackers and bread makes it easier to eat an excess of calories and gain weight. Since the National Institutes of Health report that more than 2 of 3 American adults are considered to be overweight or obese, it may be wise to limit consumption of these products.
- Satiety
In general, whole grain flour products may not make you feel as full as the intact whole grain. This is also due in part to the higher water content inside the cooked whole grain. Refined grain flour products make you feel even less full than whole grain flour products because they don’t contain fiber.
In summary, whole grain flour has all the same nutrients as the intact whole grain it came from, but due to the increased surface area, it is sensed and processed by the body differently. Despite this, whole grain flour products are still much healthier than products made from refined flour. I hope this helps drive home the idea that a “whole food” is healthier than many processed convenience foods. Scientific research likes to focus on one tiny isolated aspect of a food instead of the whole food. This is very useful for understanding physiology, but it can divert attention away from the importance of the whole food. For example, much of the beneficial nutrition of an oat is attributed to its beta-glucan fiber. However, this is a vast oversimplification. If all of the benefits of oats were from beta-glucan fiber, we could just sprinkle powdered oat bran (a rich source of beta glucan fiber) on other foods to get all the benefits of oats, but that doesn’t work. Why? Because we’re taking one part of the oat out of the context of its whole food. Oats include healthy macronutrient fats, healthy starches and healthy protein. They contain healthy micronutrients such as folate, zinc, iron, selenium, copper and manganese. Oats also contain a plethora of phytochemicals including alpha tocotrienols and alpha tocopherols (two forms of vitamin E), protocatechuic, p-hydroxy benzoic acid, vanillic, syringic, ferulic, caffeic, p-coumaric, sinapic, apigenin, glycosylvitexin, isovitexin, tricin, vitexin, avenanthramides, and trace amounts of flavonoids. All these fancy words may not mean a lot to you, but they mean a lot to the health of the human body. There are probably more chemicals in oats that we don’t know about and they all interact together to make the oat healthy.
To put this all in perspective: oats have a ton of beneficial nutrition, but hardly anyone eats them. A recent estimate from NHANES dietary recalls shows that only 6% of Americans eat cooked oatmeal of any non-flour form, and this number is mostly children under the age of 2 and women over the age of 45. If all Americans ate oats for weekday breakfast, our nation would be significantly healthier.
“Fill, what if I’m not quite ready to eat oats for breakfast? What about my Cheerios? You never gave me a final answer about whether those are healthy or not.”
Cheerios are made from whole oats, so they contain all the nutrients of a whole oat. But since they are made from oats ground all the way down into flour, they are processed by the body in a way that is less healthy than an intact whole oat. In addition, Cheerios undergo additional food processing steps to include extrusion, “puffing,” and the addition of other ingredients that we haven’t discussed. Overall, eating Cheerios is healthier than eating donuts, cinnamon rolls, and many other breakfast convenience items. If your decision is between Cheerios or donuts, pick Cheerios. But if you find a healthy oat recipe that tastes good and you don’t mind eating that instead of Cheerios, then do it! Ultimately, my mission is to give you the knowledge to replace something you eat with something healthier, one meal at a time.
“Okay Fill, I like the idea of making one meal substitution at a time. But I’m still busy. I don’t have time to cook a nice breakfast every morning. I NEED something convenient.”
Although I think we all need to cook at home more to eat healthier, I also believe that food needs to be convenient to make, and it needs to taste good in order to maintain a long-term eating pattern. We need to find recipes to suit our busy lifestyles. When it comes to oats, I think a combination of pressure cooking and batch cooking presents the best solution. Pressure cooking significantly reduces the amount of time it takes for intact grains to gelatinize, and electronic pressure cookers reduce the need to monitor the food while it’s cooking. Batch cooking also reduces the amount of time spent on redundant cooking.
I love to make a week’s worth of steel cut oats in my pressure cooker on the weekend and eat it every morning throughout the week. But you could just as easily make some daily ‘overnight oats’ in the fridge using old-fashioned rolled oats. Either way, buy them plain and add your own toppings to avoid the unhealthy additives. Whatever recipe you choose, remember that it must taste good or you won’t eat it again.
When it comes to eating healthier, the first imperative step is that you at least try a new recipe. Whenever you try a new recipe, keep in mind that you may have to search the grocery store for a long time to find a new ingredient, you may cook it wrong, and you may not like how it tastes. If you acknowledge these possibilities beforehand, you’ll be less disappointed if it happens. The second imperative step is to make the recipe your own. You have your own tastes, your own kitchen gadgets, your own size family. Make the recipe fit your needs. Lastly, don’t go all or nothing if you aren’t ready. When many people try a new diet, they feel so compelled to eat healthy that they feel guilty about eating anything slightly unhealthy, including many of their staple home meals. I think this is the wrong way to approach dietary changes. Most successful eating changes are instead made in small steps, allowing time for your pantry, family members and tastebuds to adapt to gradual changes. All I care about is that you make changes to eat healthier than you are currently eating. Think about it as competing for a personal best in your own food diary.
So if you don’t currently eat oats, try a new oat recipe. If you don’t have a pressure cooker, use old-fashioned oats, they are basically just as healthy. If you are worried about taste, try making some oats with peanut butter, banana slices and a few chocolate chips on top. I’m pretty sure anyone would eat that. Are there some unhealthy ingredients? Yes, but if it’s healthier than what you were eating, make the switch. Even if there are some unhealthy ingredients, you have the option of substituting these for something healthier down the road. You can buy peanut butter made only from peanuts and no added hydrogenated oil, sugar or salt. The texture and oil separation don’t matter if you’re blending it into the oats. When you’re willing to give up chocolate chips, try unsweetened cocoa powder on the banana slices. And if you really want to eat healthy, then try oats with blueberries, walnuts, cinnamon and a minimal amount of honey or pure maple syrup to sweeten it up. If you don’t need the added sugar, then don’t add it. If your berries go bad in the fridge, then buy them frozen, they’re just as healthy. Find a way to make it convenient and delicious. With that mindset, it’s no longer a diet, it’s an adventure 🙂
-Photo by Amanda Belec on Unsplash
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https://nutritionfacts.org/video/can-oatmeal-reverse-heart-disease/
https://nutritionfacts.org/video/can-oatmeal-help-fatty-liver-disease/
https://www.healthline.com/nutrition/foods/oats#section7
https://www.healthline.com/nutrition/rolled-vs-steel-cut-oats
https://www.hsph.harvard.edu/nutritionsource/food-features/oats/
Fill, M.D. 