Are Overnight Oats Healthy?

Are Overnight Oats Healthy?

The Answer to a Healthy Breakfast is Simple


Do you have fond childhood memories of eating sugary cereal for breakfast every day? I sure do! This will always hold a special place in our hearts. Now, we know that this stuff causes blood sugar crashes, leaves us feeling hangry an hour later, and is completely lacking in the nutrition department (unless you count the stuff they add back in).

So, what makes for a better breakfast option?

I’ll give you a clue, it’s a whole grain that is naturally rich in nutrients, especially fiber and antioxidants.

You guessed it, OATS!!!

Why are Oats so Healthy?

  •  Contain many nutrients:
    • Good source of carbohydrates and quality protein
    • FIBER: cellulose, arabinoxylan and beta-glucan
    • Unsaturated fatty acids
    • Vitamins: thiamine, niacin, folate, vitamin E, and riboflavin
    • Minerals: calcium, iron, magnesium, and phosphorous
    • Phytochemicals (antioxidant and anti-inflammatory properties): polyphenols (including avenanthramides)
  • Are a type of resistant starch:
    • Type of starch that mimics fiber
    • Cannot be digested in the small intestine, so it is metabolized by microbes in the gut
    • Acts as a prebiotic (promotes the growth of beneficial bacteria in our gut)
  • Are a slow carbohydrate:
    • Oats contain high amounts of fiber, which slows digestion and absorption of glucose into the bloodstream
    • Will not spike our blood glucose or insulin levels like fast carbs do

Why Beta-glucans & Avenanthramides are so important:

  • Beta-glucans
    • Soluble dietary fiber
    • Acts as a prebiotic (promotes the growth of beneficial bacteria in our gut)
    • Suppresses appetite/increases feelings of satiety
    • Has been shown to reduce LDL (“bad”) cholesterol, while significantly improving HDL (“good”) cholesterol
    • Has been shown to reduce glucose and insulin responses, and improve insulin sensitivity both in diabetic and nondiabetic individuals
  • Avenanthramides (AVAs)
    • Unique group of antioxidants found only in oats (are not found in other cereal grains)
    • Have an antioxidant activity of 10–30x greater than other phenolic antioxidants
    • Have anti-inflammatory, anti-atherogenic (prevents the formation of fatty plaque in arteries), anti-proliferative (helps to prevent the spread of malignant cells/tumor formation), and anti-cancer properties
    • Have been suggested to play a protective role against several chronic diseases, including cardiovascular diseases, cancer, and diabetes

Oats: The Basics

Different Type of Oats

Oats are a type of cereal grain, which come from the edible seeds of oat grass.

Like most unprocessed cereal grains, oats need to be processed for their nutrients to become bioavailable. This is because the hull (outer part of the seed) is highly indigestible and needs to be removed.

What is inside an oat kernel (aka seed)?

  • Hull: the outer, protective part of the oat seed
  • Groat: the portion of the seed that is protected by the hull and makes up the majority of the grain kernel (68-72%); the groat contains the bran, germ, and endosperm (all edible)
    • Bran: the outer layer of the groat that is an important source of protein, neutral lipids, beta-glucan, polyphenols, and niacin
    • Germ: inner portion of the groat that contains mostly lipids and protein
    • Endosperm: inner portion of the groat that contains mostly starch, along with some proteins and beta-glucan

Remember, whole grains contain all three edible parts of the seed, whereas refined grains only contain the starchy endosperm.

Now that we understand what makes up an oat kernel, let’s talk about different types of oats (listed in order of least processed to most processed):

  • Whole Oat Groats: portion that is left after the hull is removed; Contains all three parts of the seed (the bran, endosperm, and germ), which makes it a whole grain; Have a hearty, chewy texture, and nutty flavor; Take the longest to cook
  •  Oat Bran: outer layer of the groat, which is separated during processing; Is creamier than other types of oats and usually cooks much faster
  • Steel Cut Oats: Made from oat groats that are cut into smaller pieces; Have a somewhat chewy, chunky texture and take longer to cook
  • Old Fashioned Oats (Rolled Oats): Made from oat groats that are steamed, rolled, and flattened into flakes, then dried to remove moisture
  • Instant Oats: Most processed type of oats that usually come sweetened and artificially flavored; Made from oat groats that are steamed longer and rolled into thinner pieces than rolled oats; Cook the fastest

Which type of oats should I be eating?

Oat groats are the least processed, most whole form of oats, which makes them the most nutritious. This means that they are not treated with excessive amounts of pressure and heat, which can degrade nutrients, especially antioxidants.

How Processing Impacts Blood Sugar

Oat Groats

The more processed a carbohydrate is, the faster it will be digested and absorbed, which can cause a spike in blood sugar and insulin (see our blog on carbs for more info).

Over time, this can lead to weight gain and an increased risk for developing diabetes and cardiovascular disease.

So, because oat groats undergo the least amount of processing compared to other types of oats, they will be the slowest to absorb into the bloodstream.

Following oat groats in terms of processing are: oat bran, steel-cut oats, old-fashioned oats, and instant oats.

On the other hand, because instant oats are the most processed (also contain added sugars), they are quickly digested, which is likely to trigger a spike in blood sugar and insulin.

But... Let’s remember that all oats (with possibly the exception of highly processed instant oats) are healthy whole grains that we recommend eating!

How to Make Oats Even Healthier

There is a way to greatly enhance the nutritional value of even the healthiest types of oats… Sprout them!

Benefits of sprouting oats:

  • Makes them easier to digest (sprouting helps to remove antinutrients that interfere with digestion)
  • Increases bioavailability of nutrients, including protein, albumin (rich in essential amino acids lysine and tryptophan), and phytochemicals (sprouting increases avenanthramides by up to 20%)

Why You Need to Upgrade your Breakfast with Sprouted Oats!

If oats are considered to be a health food, then sprouted oats are a superfood!

Why should you try sprouted oats?

  • More nutritious
  • Contain more antioxidants
  • Keeps you full
  • Easier to digest
  • Helps improve the health of our microbiome

Don’t have the time to sprout your own whole oat groats?

We got you covered! Try our OverNights, which contain oat groats that are raw AND sprouted.

Why raw?

Raw means that the oat groats were not processed with intense heat that would destroy the bioavailability of micronutrients, especially antioxidants.

These breakfasts are extremely convenient, not to mention packed with nutrition and taste delicious!



  • Bulsiewicz, Will. Fiber Fueled: The Plant-Based Gut Health Program for Losing Weight, Restoring Your Health, and Optimizing Your Microbiome. Penguin Random House, 2020.
  • Decker, Eric A., Devin J. Rose, and Derek Stewart. "Processing of oats and the impact of processing operations on nutrition and health benefits." British Journal of Nutrition 112.S2 (2014): S58-S64.
  • Kessler, David. Fast Carbs, Slow Carbs: The Simple Truth about Food, Weight, and Disease. HarperCollins, 2020.
  • Lam, Ka-Lung, and Peter Chi-Keung Cheung. "Non-digestible long chain beta-glucans as novel prebiotics." Bioactive carbohydrates and dietary fibre 2.1 (2013): 45-64.
  • Rasane, Prasad, et al. "Nutritional advantages of oats and opportunities for its processing as value added foods-a review." Journal of food science and technology 52.2 (2015): 662-675.
  • The Nutrition Source: Oats. Harvard T.H. Chan School of Public Health, The President and Fellows of Harvard College, oats/.

Trish Shea

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