Oatmeal, blood sugar, and working out

Oatmeal is an important source of carbohydrates, soluble fiber, protein, and minerals.  While there are many demonstrated and more widely known health benefits (i.e., cholesterol management) to oatmeal, this blog post focuses on its effects on blood sugar in general and why this matters for exercise and athletes. Other blog posts will explore additional benefits. To listen to a 15-minute podcast summary of the literature review, click here.

First of all, oats are best known for being a formidable source of fiber with 1/2 cup containing 16% of the daily value, followed by protein (6g, 12%), carbohydrates (11%), iron (10%), potassium (4%), and calcium (2%) (1). A serving of oats this size alone is approximately 175 calories which makes this a great source of energy for exercise. 

Oats help maintain healthy blood sugar levels: The American Diabetes Association lists oatmeal as a 'superstar food' when managing diabetes (2). Rolled oats have a low-to medium glycemic index at 55 which helps maintain blood sugar levels (1)- the glycemic index is a tool used to assess the impact of carbohydrates on blood glucose levels. Participants in one study who consumed oatmeal at the intervals in the study were at significantly lower risk of developing Type 2 diabetes (4), and in another study, participants who ate oatmeal showed significant reductions in daily insulin requirements (5). While there are many reasons for oatmeal's benefits to supporting healthy blood glucose levels, a strong part of it is related to it being a soluble fiber.

For athletes, oatmeal releases available energy gradually: Most athletes know that if you want to fuel your workout routine, you need carbs (i.e., carb loading). If you are exercising, your body's available energy, carbohydrates, fuels your workout. Therefore maintaining steady and consistent blood glucose levels helps ups and downs, crashes and spikes, and oats, according tot he study by Zeng et al., (2021) 'ensured a consistent and sufficient energy supply to support athletic performance (3).' Another study using a HIIT workout linked (demonstrated association, not causality) oatmeal to reducing exercise induced reactive oxygen species production (ROS)- ROS is a cause of oxidative stress.

1. Daily values taken from the supplier's analysis of oats.  
2. American Diabetes Association. Accessed June 25, 2025: https://diabetes.org/food-nutrition/food-and-blood-sugar/diabetes-superstar-foods
3. Zeng et al. (2021). Acute Effects of Oatmeal on Exercise-Induced Reactive Oxygen Species Production Following High-Intensity Interval Training in Women: A Randomized Controlled Trial.
4. Yang et al., (2020). Intake of whole grain foods and risk of type 2 diabetes: results from three prospective cohort studies.   
5. Lammert et al., (2008). Clinical benefit of a short term dietary oatmeal intervention in patients with type 2 diabetes and severe insulin resistance: a pilot study. Exp Clin Endocrinol Diabetes. doi: 10.1055/s-2007-984456
6. Zeng et al., (2020). Acute Effects of Oatmeal on Exercise-Induced Reactive Oxygen Species Production Following High-Intensity Interval Training in Women: A Randomized Controlled Trial.