How to Tell If a Starchy Food Is Ultra-Processed in 5 Seconds

Grocery store shelves are packed with breads, pastas, cereals, and snacks that are considered ultra-processed. Telling the difference is not always easy. 

Experts say two simple tests can help you quickly spot healthier grain-based products: a carb-to-fiber ratio and a look at the ingredient list.

The 10:1 Carb-to-Fiber Rule

The first test, created by Harvard University researchers in 2013, is the 10:1 carb-to-fiber rule. It involves checking to see if a product has at least 1 gram of fiber for every 10 grams of carbs.

“The intention was to help consumers find starch and grain foods that had higher fiber content and lower amounts of sugar,” said Anne VanBeber, PhD, RD, a professor in the department of nutritional sciences at Texas Christian University.

Another way to use this ratio, she said, is to look at the Nutrition Facts label for the number of carbohydrate grams and the number of fiber grams and divide the total carbohydrate grams by the fiber grams. The resulting number should be less than 10.

VanBeber said an even better ratio would be 5:1—a rule that was developed by physician and author Michael Greger, MD, to help identify healthier breads, cereals, and other starchy foods. For every 5 grams of carbohydrate, there should be at least 1 gram of fiber.

However, “this test is really only meaningful for grain-based foods, and it also falls short when a food manufacturer adds isolated fibers during processing to boost fiber content. This doesn’t make the product any less processed and doesn’t necessarily mean it’s healthier,” said Matthew J. Landry, PhD, RDN, an assistant professor of population health and disease prevention at UC Irvine Joe C. Wen School of Population & Public Health.

Starchy Foods That Could Be Considered ‘Ultra-Processed’

Foods that would not meet the 10:1 rule include:

• White bread
• White flour tortillas
• White rice
• White pasta
• Cereals made with white processed grains
• Fruit juices
• Salty snacks, such as pretzels, potato chips, and pita chips

Healthier Starchy Foods That Meet the 10:1 Rule

Starchy foods that might meet the 10:1 carb-to-fiber target are:

• Whole wheat bread, tortillas, and pasta
• Corn tortillas
• Oats
• Quinoa
• Barley
• Teff
• Legumes, such as black beans, chickpeas, navy beans, pinto beans, etc.
• Some brown rice and wild rice
• Whole fruits and vegetables
• Nuts and seeds

Reading the Nutrition Label Is Easiest

Math isn’t always necessary to determine if a food is ultra-processed. Landry said the most reliable approach is simply reading the ingredient list.

“If the first ingredient is ‘enriched flour’ rather than a whole grain, that can be a red flag,” he said. “Since ingredients are listed by weight, if ‘whole wheat’ or another whole grain is listed very early in the list, that means that product is made primarily of that.”

Additionally, when looking at the ingredients list, he said you’ll want to look for ingredients you typically wouldn’t find in your home kitchen, such as emulsifiers, artificial flavors, modified starches, and color additives. These suggest that an item is ultra-processed.

However, relying solely on unfamiliar-sounding ingredients can be misleading, since some additives are genuinely beneficial or benign (ascorbic acid is simply vitamin C, thiamin is vitamin B1), he said.