Oatmeal (rolled oats, cooked): GI, GL, Carbs & Blood Sugar Impact

Glycemic index of rolled oats (55), glycemic load, carbs per cup, instant vs rolled oats, and diabetes-friendly oatmeal.

Category: Grains & Starches · Nutrition data source: USDA FoodData Central · GI source: International Tables of GI & GL Values / University of Sydney · Last verified:
55 Glycemic Index Moderate
13.4 Estimated GL 1 cup cooked with water (234 g)
28.3 g Carbohydrate per 1 cup cooked with water (234 g)
4.0 g Fiber per 1 cup cooked with water (234 g)

Does Oatmeal Raise Blood Sugar?

Rolled oats cooked with water carry about 28 g of carbohydrate per cup with a published GI around 55 — moderate, with real fiber. The trap is the versions around it: instant/quick oats test considerably higher, and sugar, honey and dried-fruit toppings add a fast carbohydrate hit.

How to Eat It

Rolled (not instant) oats, cooked with water or milk, topped with berries and nuts rather than sugar and syrup. A normal bowl fits most diabetes-friendly plans.

Nutrition Facts (Oatmeal (rolled oats, cooked))

NutrientPer 100 gPer serving
Calories71 kcal166 kcal
Carbohydrate12.1 g28.3 g
Fiber1.7 g4.0 g
Sugars0.3 g0.7 g
Protein2.4 g5.6 g
Fat1.5 g3.5 g

Source: USDA FoodData Central (generic food item, per 100 g edible portion). Values may differ from brand-specific products.

Glycemic Index

Published GI: 55 (typical value).
Reported range: 55-83.
Evidence level: Moderate.
Note: Rolled oats test around 55; instant/quick oats test considerably higher (75+).

Sources: International Tables of Glycemic Index and Glycemic Load Values (2008/2021); University of Sydney GI Database (glycemicindex.com). GI values are reported relative to a glucose reference.

Learn more: What is GI? · What is GL? · GI vs GL

Estimated Glycemic Load

GL ≈ 13.4 per 1 cup cooked with water (234 g).

Calculation: GI (55) × available carbohydrate per serving (24.3 g = 12.1 g − 1.7 g fiber) ÷ 100. Calculated by DMSafeHaven; formula per standard published GL methodology.

Diabetes consideration: Rolled oats in a normal serving are a moderate, fiber-carrying breakfast - the instant varieties and sweet toppings are what push it over.
What can change the impact?
  • Rolled vs. instant oats
  • Toppings (sugar, honey, dried fruit)
  • Portion size

GI values can vary with variety, ripeness, preparation and testing conditions. The value above is a typical published figure, not a universal prediction for every individual or every serving.

DMSafeHaven provides educational information based on publicly available nutrition databases and published research. It is not a substitute for individualized medical advice. Nutrition values: USDA FoodData Central (CC0). GI values: published tables (see methodology). GI/GL estimates do not predict any individual's glucose response — test your own blood glucose with your care team's guidance.