Oatmeal made from rolled or steel-cut oats is one of the few breakfast staples that stays in the low-GI range. Most boxed cereals don’t: corn flakes, puffed rice, and even bran flakes test above 70. The standout exception is original All-Bran, at 44.
Below are GI and GL values for 17 cereals, the swaps that matter most, and a shopping list you can print.
- Cereal GI table
- What makes cereal lower
- Best and worst picks
- Smart swaps
- Shopping list
- Tips
- FAQ
- Printable
Lowest GI: original All-Bran (44)
Highest: Rice Krispies (82)
Easiest swap: instant oatmeal (79) for rolled oats (55). Same grain, different processing.
Glycemic index of oatmeal and cereals: 17 compared
| Cereal | GI | GL | Serving | Fits these plans | |
|---|---|---|---|---|---|
 |
All-Bran (original) Lowest-GI boxed cereal |
44 | 6 | 30 g | Low-GI, South Beach P2, Mediterranean, Diabetes-friendly |
 |
Oatmeal, steel-cut Chewier, slightly lower |
52 | 12 | 250 g cooked | Low-GI, South Beach P2, Mediterranean |
 |
Oatmeal, rolled oats The everyday low-GI pick |
55 | 13 | 250 g cooked | Low-GI, South Beach P2, Mediterranean |
 |
Oat bran Stir into other cereals |
55 | 3 | 10 g | Low-GI, South Beach P2, Mediterranean, Diabetes-friendly |
 |
Muesli, no added sugar | 57 | 11 | 30 g | Mediterranean |
 |
Frosted Mini-Wheats | 58 | 12 | 30 g | — |
 |
Raisin Bran | 61 | 12 | 30 g | — |
 |
Cream of Wheat | 66 | 17 | 250 g cooked | — |
 |
Special K | 69 | 14 | 30 g | — |
 |
Grape-Nuts | 71 | 15 | 30 g | — |
 |
Bran flakes | 74 | 13 | 30 g | — |
 |
Cheerios | 74 | 15 | 30 g | — |
 |
Shredded wheat | 75 | 15 | 30 g | — |
 |
Oatmeal, instant Same oats, ground finer |
79 | 21 | 250 g cooked | — |
 |
Puffed wheat | 80 | 17 | 30 g | — |
 |
Corn flakes | 81 | 21 | 30 g | — |
 |
Rice Krispies Highest GI here |
82 | 21 | 30 g | — |
Sorted lowest to highest GI. GI: low 55 or less, medium 56–69, high 70+. GL per serving: low 10 or less, medium 11–19, high 20+. Oatmeal servings are cooked weight; boxed cereals are dry weight, before milk. No cereal here fits keto or Atkins Phase 1.
What makes one cereal lower than another
Processing. The same oats test at 52 as steel-cut, 55 as rolled, and 79 as instant. The thinner an oat is rolled and the more it’s precooked, the faster it digests.
Puffing and flaking. Puffed and flaked cereals are cooked and expanded during manufacturing, which leaves the starch quick to break down. That’s why corn flakes (81), Rice Krispies (82), and puffed wheat (80) sit at the top of the list.
“Bran” isn’t automatically low. All-Bran’s dense sticks test at 44. Bran flakes, made from flaked wheat, test at 74.
Portion size. A 30 g serving of dry cereal is roughly one cup of flakes, and most people pour two. Double the bowl and you double the GL.
Best and worst picks
Best picks (GI 55 or less)
- All-Bran, original (44)
- Steel-cut oats (52)
- Rolled oats (55)
- Oat bran (55)
Middle of the road
- Muesli, no added sugar (57)
- Frosted Mini-Wheats (58)
- Raisin Bran (61)
Limit (GI 70 or more)
- Rice Krispies (82)
- Corn flakes (81)
- Puffed wheat (80)
- Instant oatmeal (79)
- Shredded wheat (75)
- Cheerios (74)
- Bran flakes (74)
- Grape-Nuts (71)
Smart swaps
| Instead of | Try | The difference |
|---|---|---|
| Instant oatmeal | Rolled or steel-cut oats | GI 79 → 52–55 |
| Corn flakes | All-Bran, original | GL 21 → 6 |
| Rice Krispies | Muesli, no added sugar | GI 82 → 57 |
| Bran flakes | All-Bran, original | GI 74 → 44 |
| Cheerios | Rolled oats | GI 74 → 55 |
| Cream of Wheat | Steel-cut oats | GI 66 → 52 |
Low-GI breakfast cereal shopping list
- Rolled oats (old-fashioned)
- Steel-cut oats
- Oat bran
- All-Bran, original
- Muesli with no added sugar
Reading the label:
- Buy “old-fashioned,” “rolled,” or “steel-cut” oats, not “quick” or “instant.” Quick oats are rolled thinner and land in between.
- Flavored instant packets add sugar on top of an already high-GI base.
- Granola is usually muesli baked with sweetener and oil. If sugar is in the first three ingredients, it’s closer to dessert.
- “Whole grain” on a box doesn’t mean low GI. Cheerios and shredded wheat are both whole grain and test at 74–75.
Tips to help you succeed
- Batch-cook your oats. I make a pot of steel-cut oats on Sunday and reheat a portion each morning. It takes about as long as an instant packet.
- Add protein or fat. Greek yogurt, a handful of nuts, or a spoonful of nut butter slows how fast the carbs reach your bloodstream.
- Cut a favorite cereal with a better one. If you won’t give up your usual box, mix it half and half with All-Bran or oat bran.
- Measure your bowl once. Pour your usual amount into a measuring cup one time. Most of us pour two servings without knowing it.
- Skip the juice. A glass of orange juice adds a GL of about 13 to breakfast. Whole fruit on the cereal is the better trade.
How I eat breakfast
Most mornings it’s steel-cut or rolled oats with a handful of walnuts and some berries. When I want something crunchy, I reach for All-Bran or unsweetened muesli instead of flakes or puffs. Instant packets stay in the cupboard for travel days.
Frequently asked questions
Is oatmeal low glycemic?
Rolled oats (55) and steel-cut oats (52) are low GI, though right at the top of the range. Instant oatmeal is high, at 79. What you add matters too: brown sugar and dried fruit push a low-GI bowl up quickly.
Are steel-cut oats better than rolled oats?
Slightly. Steel-cut tests at 52 versus 55 for rolled, a small difference. Both are far better than instant. Pick the one you’ll actually eat.
What is the lowest glycemic cereal?
Of the cereals with published tests, original All-Bran is lowest at 44, followed by steel-cut oats (52), rolled oats and oat bran (55), and unsweetened muesli (57).
Are Cheerios low glycemic?
No. Original Cheerios test at 74, in the high range, even though they’re made from whole-grain oats. The oats are ground into flour and puffed, which speeds digestion.
Can you eat oatmeal on South Beach or keto?
South Beach Phase 1 excludes grains, including oats. From Phase 2, rolled and steel-cut oats are back in moderation. Oatmeal doesn’t fit keto: one bowl has about 23 g of carbs.
Printable cereal list
A free one-page version of this list is coming soon. For the full printable set covering every food group, see the glycemic index food lists at Health List Now.
GI values vary between tests. This page is general information, not medical advice. Last reviewed October 2026.