Ultra-processed foods and sweets
Corn flakes
Corn flakes pack 384 kcal into 100 g (3.5 oz), so a typical 30 g (1 oz) serving already adds up to about 115 kcal.
Estimated satietyHow it is calculated
Estimated satiety: 1 out of 5
| Starting point | +1 |
|---|---|
| High energy density | −1 |
| Sum | 0 |
| Raised to the minimum of 1 | 1 |
Our own estimate from the values per 100 g: useful for comparing foods with each other, not a measurement in people. Holt index (1995): 118 (white bread = 100).
- Prepared by
- Alex Gonzalez
- Last updated
- Next review
- Sources
- 7 primary
- Data
- USDA FDC 174648
No clinical review. No advertising from drug companies and no affiliate links.How we work
Nutrition facts
- Calories
- 115 kcal per serving
- 384 kcal per 100 g (3.5 oz)
- Protein
- 1.8 g per serving
- 5.9 g per 100 g (3.5 oz)
- Carbohydrates
- 26.4 g per serving
- 88 g per 100 g (3.5 oz)
- of which sugars
- 2.4 g per serving
- 7.8 g per 100 g (3.5 oz)
- Fiber
- 0.8 g per serving
- 2.7 g per 100 g (3.5 oz)
- Fat
- 0.3 g per serving
- 0.9 g per 100 g (3.5 oz)
- of which saturated
- 0.1 g per serving
- 0.2 g per 100 g (3.5 oz)
- Water
- 1 g per serving
- 3.3 g per 100 g (3.5 oz)
Source: USDA FoodData Central: Cereals ready-to-eat, RALSTON Corn Flakes (FDC ID 174648), accessed September 23, 2026.
A typical 30 g (1 oz) serving provides about 115 kcal, 1.8 g of protein, and 0.8 g of fiber.
What it is and how to eat it
Corn flakes are a breakfast cereal made from corn in the shape of flakes or small thin sheets, usually eaten with milk; the Diccionario de americanismos calls them hojuelas de maíz in Nicaragua, Cuba, Colombia, Ecuador and Chile. This page uses a branded corn flakes cereal analyzed by USDA, without a sugar coating, with 384 kcal, 88 g of carbohydrates, 7.84 g of sugars, 2.7 g of fiber and 5.9 g of protein per 100 g. Recipes change from brand to brand, so the label is the best guide.
A 30 g (1.1 oz) serving provides 115 kcal, 0.3 g of fat, 2.4 g of sugars and only 1.8 g of protein. It is low in fat and fiber, which can help in the first days of treatment, when the 2025 nutrition advisory on GLP-1 therapy suggests avoiding fatty or high-fiber foods and eating smaller, more frequent meals. Because it provides little protein, which the same advisory suggests eating first, it works better with milk or Greek yogurt, as in the Greek yogurt with fruit and seeds, than as a meal on its own.
What the evidence says
In the Holt satiety index (1995), corn flakes scored 118, slightly above white bread, the reference (100); the index measures how full people feel over the two hours after 240 kcal servings. Their glycemic index is high, 81 in the 2008 international tables, compared with 75 for white bread. According to USDA they have 571 mg of sodium per 100 g, so 30 g provides 171 mg, close to 9% of the 2,000 mg a day that WHO recommends not exceeding. With those figures and Mexico's NOM-051, which requires warning seals on packaged foods with added sugars, fats or sodium, I calculate, assuming added salt, that they would carry "EXCESO CALORÍAS" (excess calories), because they exceed 275 kcal per 100 g, and "EXCESO SODIO" (excess sodium), because they exceed 1 mg of sodium per kcal, but not "EXCESO AZÚCARES" (excess sugars), since even if all their sugars were added they would provide 8.2% of energy, below the 10% threshold.
Satiety
The 1 to 5 score is our own estimate: it starts at 1 point, adds points for low energy density, for protein and fiber per 100 kcal, and for the water in solid foods, and subtracts points for drinks with calories. It is useful for comparing foods with each other; it is not a measurement in people.
This food was measured in people: in the satiety index by Holt and colleagues (1995), which compared 240 kcal servings of 38 foods over two hours, it scored 118 versus 100 for white bread. In other words, it was more filling than the same calories of white bread. Source: Holt SH, Miller JC, Petocz P, Farmakalidis E. A satiety index of common foods. Eur J Clin Nutr. 1995;49(9):675-90.
What to keep in mind on a GLP-1 medication
Frequently asked questions about corn flakes
How many grams of protein are in a cup of corn flakes?
A cup of corn flakes, our reference serving of 30 g (1 oz), has about 1.8 g of protein. 100 g (3.5 oz) of corn flakes has 5.9 g of protein. That is 1.5 g of protein per 100 kcal.
How many kcal are in a cup of corn flakes?
A cup of corn flakes, our reference serving of 30 g (1 oz), has about 115 kcal. 100 g (3.5 oz) of corn flakes has 384 kcal. That is a high energy density.
How much fiber is in a cup of corn flakes?
A cup of corn flakes, our reference serving of 30 g (1 oz), has about 0.8 g of fiber. 100 g (3.5 oz) of corn flakes has 2.7 g of fiber.
Do corn flakes keep you full?
Barely filling for the calories they provide: our estimated satiety score is 1 out of 5. It is based on: high energy density. They were also measured in people: in the Holt satiety index (1995), with 240 kcal servings, they scored 118 versus 100 for white bread.
How do corn flakes fit into eating on Ozempic, Wegovy, Mounjaro, or Zepbound?
Based on our tags, this is what matters about corn flakes on a GLP-1 medication. “High energy density”: a lot of energy in a small volume; when your appetite is very low, a small serving can help you meet your needs. These are general guidelines, not medical advice: everyone tolerates foods differently.
What is a typical serving of corn flakes?
We use 30 g (1 oz) as a typical serving, roughly a cup of corn flakes. That amount provides about 115 kcal, 1.8 g of protein, and 0.8 g of fiber. It is a reference for calculations, not a recommendation of how much to eat.
Compare with…
Similar foods
Sources
Sources for the data on this page, with the access date.
- Official databaseU.S. Department of Agriculture, Agricultural Research Service.USDA FoodData Central: Cereals ready-to-eat, RALSTON Corn Flakes (FDC ID 174648).accessed .
- Clinical trialEuropean Journal of Clinical Nutrition.Holt SH, Miller JC, Petocz P, Farmakalidis E. A satiety index of common foods. Eur J Clin Nutr. 1995;49(9):675-90.accessed .
- InstitutionAssociation of Academies of the Spanish Language (ASALE).Diccionario de americanismos (Dictionary of Americanisms): "hojuela (hojuelas de maíz)" (in Spanish).accessed .
- Clinical guidelineObesity (Wiley).Mozaffarian D, et al. Nutritional priorities to support GLP-1 therapy for obesity: A joint Advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society. Obesity. 2025;33(8):1475-1503. doi:10.1002/oby.24336.accessed .
- Official databaseDiabetes Care (American Diabetes Association).Atkinson FS, Foster-Powell K, Brand-Miller JC. International tables of glycemic index and glycemic load values: 2008. Diabetes Care. 2008;31(12):2281-2283. doi:10.2337/dc08-1239.accessed .
- InstitutionWorld Health Organization.Sodium reduction.accessed .
- RegulatorDiario Oficial de la Federación (Ministry of Economy and Ministry of Health, Mexico).Modificación a la Norma Oficial Mexicana NOM-051-SCFI/SSA1-2010 (Mexico's labeling standard for prepackaged foods and non-alcoholic beverages), Diario Oficial de la Federación, March 27, 2020; section 4.5.3, Table 6 and second transitory article (in Spanish).accessed .