The Breakfast Cereal Report
Breakfast cereal is the aisle where added sugar hides in plain sight. There's no sugar ceiling a box has to clear to print "whole grain," "protein," or "fit" on the front — so we graded 28 cereals against their USDA labels and ranked them by the numbers that actually matter: sugar per serving, sugar per 100 calories, and the fiber and protein a bowl really delivers. The spread is enormous.
The short answer
Across 28 cereals, sugar runs from 0 g to 21 g per serving and averages 8.9 g — and 54% carry 10 g of sugar or more in a single bowl. That's not a category — it's two different foods on the same shelf. At the top are genuinely good options: plain oats and high-fiber or grain-free protein cereals that deliver real fiber or protein with little sugar. At the bottom are sugar-delivery vehicles, many of them wearing "whole grain," "protein," or "fit" claims that say nothing about the sugar behind them. The sugariest cereal we graded is Kellogg's Frosted Flakes Cereal at 21 g per serving. The honest metrics are sugar-per-serving, sugar-per-100-calorie, and the fiber and protein actually on the panel — not the adjective on the box.
The sugariest cereals
Sugar per serving, highest first. Remember these are measured on a small dry portion — a realistic bowl pours more. Several here lead with sugar as one of the first ingredients.
| Cereal | Sugar | Sugar / 100 cal | Grade |
|---|---|---|---|
| Kellogg's Frosted Flakes Cereal | 21 g | 9.5 g | C- |
| Nature Valley Oats & Honey Protein Granola | 16 g | 5.9 g | B- |
| Quaker Simply Granola (Oats, Honey, Raisins & Almonds) | 16 g | 5.9 g | B+ |
| Cascadian Farm Organic Oats & Honey Granola | 14 g | 5.2 g | B- |
| Quaker Instant Oatmeal Maple & Brown Sugar 1.69 oz | 14 g | 7.8 g | C |
| Kellogg Company Us Kashi Golean Cereal Original 15.8oz | 12.7 g | 6.5 g | B |
| Quaker Life Original Multigrain Cereal | 12.6 g | 5.2 g | C+ |
| Cheerios Protein Cinnamon Cereal | 12 g | 8 g | C+ |
| General Mills Cinnamon Toast Crunch Cereal | 12 g | 7.1 g | C |
| Kashi GO Honey Almond Flax Crunch | 11.5 g | 5.8 g | B |
The best-graded cereals
What good actually looks like: low sugar paired with real fiber or protein. Ranked by overall Labelgrade.
| Cereal | Grade | Sugar | Fiber | Protein |
|---|---|---|---|---|
| Mccann'S, Quick & Easy Steel Cut Irish Oatmeal | A- | 1 g | 4 g | 4 g |
| Quaker Old Fashioned Oats | A- | 1 g | 4 g | 5 g |
| Catalina Crunch Chocolate Banana Cereal | A- | 0 g | 9 g | 11 g |
| Quaker Instant Oatmeal, 11.6 oz | A- | 0 g | 4 g | 5 g |
| Three Wishes Cocoa Grain-Free Cereal | B+ | 3 g | 4 g | 8 g |
| Magic Spoon Fruity Grain-Free Cereal | B+ | 0 g | 1 g | 13 g |
| Quaker Simply Granola (Oats, Honey, Raisins & Almonds) | B+ | 16 g | 7 g | 7 g |
| Kashi GO Honey Almond Flax Cereal | B | 8 g | 13 g | 11 g |
Most fiber and protein per bowl
The genuinely useful picks — the cereals that earn their place by delivering real fiber or protein, not a wholesome-sounding name. Ranked by the better of the two macros per serving.
| Cereal | Fiber | Protein | Sugar | Grade |
|---|---|---|---|---|
| Kellogg's Special K Protein Honey Almond Ancient Grains | 5.64 g | 15.5 g | 9.42 g | B |
| Kellogg'S Special K Cereal Protein Plus 19oz | 4.72 g | 15.4 g | 8.08 g | B |
| Kashi GO Honey Almond Flax Cereal | 13 g | 11 g | 8 g | B |
| Magic Spoon Fruity Grain-Free Cereal | 1 g | 13 g | 0 g | B+ |
| Nature Valley Oats & Honey Protein Granola | 4.03 g | 13 g | 16 g | B- |
| Kodiak Cakes Maple & Brown Sugar Oatmeal, Maple & Brown Sugar | 3 g | 12 g | 10 g | B |
| Catalina Crunch Chocolate Banana Cereal | 9 g | 11 g | 0 g | A- |
| Kellogg Company Us Kashi Golean Cereal Original 15.8oz | 7.68 g | 8.85 g | 12.7 g | B |
How we measured it
We pulled every graded cereal in the catalog — anything whose USDA category matches "cereal" ("Cereal," "Processed Cereal Products," "Oats & Hot Cereal," and the ready-to-eat variants) — and kept the 28 with calories and sugar reported. Sugar per serving is straight off the label; sugar per 100 calories is sugar grams divided by calories, times 100, which exposes how sugar-dense a bowl is independent of the pour size on the box. Fiber and protein are per the USDA serving. Every figure is computed live from the product pages, so the numbers never drift from the underlying grades. Full method: labelgrade.com/methodology. Pairs with the added-sugar report and the protein bar report.
Cite this analysis
Free to cite with attribution to Labelgrade (labelgrade.com). Writers covering breakfast cereal, added sugar, or food marketing are welcome to use the figures above — please link to this page. For a custom cut, reach us via the contact page.
Frequently Asked Questions
Is cereal healthy?
It depends entirely on the box — that's the finding. Across the 28 cereals we graded, sugar runs from 0 g to 21 g per serving and averages 8.9 g, with 54% carrying 10 g or more in a single bowl. A handful are genuinely good: plain oats and high-fiber or grain-free protein cereals that deliver real fiber or protein with little sugar. Many more are sugar-delivery vehicles wearing a "whole grain," "protein," or "fit" label. "Cereal" is a shelf, not a nutrition standard — the only honest answer is to read the sugar, fiber, and protein on the actual panel.
What's the healthiest breakfast cereal?
By Labelgrade — which weighs sugar, fiber, protein, sodium, saturated fat, and ingredient quality together — the top of our list is Mccann'S, Quick & Easy Steel Cut Irish Oatmeal, grading a A- (88/100) with 1 g of sugar, 4 g of fiber, and 4 g of protein per serving. "Healthiest" still depends on your goal — a plain high-fiber oat for cholesterol, a grain-free protein cereal for low sugar — but the cereals that grade well share one trait: low sugar plus real fiber or protein, not a wholesome-sounding name.
How much sugar is in breakfast cereal?
Anywhere from 0 g to 21 g per serving, averaging 8.9 g across the 28 cereals we graded — and 54% pack 10 g or more in a single bowl. The sugariest we graded is Kellogg's Frosted Flakes Cereal at 21 g per serving (9.5 g per 100 cal). Watch the serving size, too: cereal sugar is measured on a small dry portion, so a realistic two-cup pour can double the number on the label.
Are "protein" or "whole grain" cereals actually better?
Sometimes — and that's exactly why the labels are unreliable. The honest test is the panel, not the front of the box: does the cereal deliver real fiber or protein without a pile of added sugar? Several cereals carrying "protein," "whole grain," or "fit" claims land among the 54% that clear 10 g of sugar per serving, while the best-graded options pair low sugar with genuine fiber or protein. A claim on the front tells you what the marketer wants you to notice; the sugar-per-serving and the fiber/protein it actually delivers tell you what you're eating.
Can I cite this analysis?
Yes — free to cite with attribution to Labelgrade (labelgrade.com). Every cereal links to a full fact sheet with the ingredient panel and the six-dimension grade.