Food and Nutrition

How to Read a Nutrition Label: Tips from a Registered Dietitian

Originally published September 19, 2022

Last updated August 25, 2023

Reading Time: 5 minutes

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Woman reading a nutrition label while shopping at the grocery store

Learn how the information on food labels can help you manage your health and wellness goals.

Odds are you’ve scanned food labels while shopping for groceries — but do you know how they can help you make healthier choices at mealtime? 

“By understanding the information on food labels — like calories, added sugars and vitamins — you can make better health decisions for you and your family,” says Stephanie McInerney, RD, a clinical nutrition specialist at Keck Medicine of USC and patient services manager at Keck Hospital of USC.

To help you navigate nutrition labels like a pro, McInerney shares 5 tips on how to read food labels and how to apply it to your daily life. 

Tip 1: Pay attention to the serving size.

“Serving size is simply the amount people typically eat or drink of a product — it’s not how much you should eat at one time or a recommended portion size,” McInerney says.

When you look at the servings per container on a nutrition facts label, pay close attention to the total number of servings. “If there are 8 servings per container and you eat the whole container, then you would need to multiply all the items on the food label by 8 to get the total number of calories and other nutrients you consumed,” McInerney says.

Tip 2: You need to do some math to get the true number of calories.

Keeping track of the number of calories you consume can help you manage your weight and other health conditions. “Excess calories in your diet may lead to weight gain and obesity — this is why it’s important to know how to read the calorie data on a food label,” McInerney says.

According to the Centers for Disease Control and Prevention (CDC), obesity affects 41.9% of U.S. adults and 19.7% of children and teenagers. And obesity-related conditions, such as heart disease, type 2 diabetes and certain cancers, are on the rise.

“When you look at the calories on a food label, it’s key to remember that the number you see only accounts for one (1) serving. To get the total number of calories, you also need to track the number of servings you eat and then multiply,” McInerney explains.

For example, if your food has 20 calories per serving and you eat 5 servings, you have to multiply 20 by 5 for a total of 100 calories. Currently, the nutrition facts label is based on an average diet of 2,000 calories per day.

“You may need more or less than 2,000 calories per day based on your specific energy needs and activity level,” McInerney says. Your primary care provider or a registered dietitian can help you determine the number of daily calories that are best for you.


Year the FDA updated the nutrition label to show new nutrition science


Calories per day for an average diet (basis for food labels)


Maximum grams of added sugar per day recommended for women


Maximum grams of added sugar per day recommended for men

Tip 3: A higher percent of daily value is not always better.

“I recommend looking at the percent of daily values (%DV) on the nutrition label because they can help us understand the impact nutrients have on our overall daily diet,” McInerney says.

The percent of daily value (%DV) showcases three important facts about your food:

  • How much a nutrient in a serving of food contributes to a daily diet
  • The amount of each nutrient per serving
  • Whether a food contains too much or too little of a nutrient

“For example, if you’re concerned about preventing or managing heart disease, it can be helpful to look at the amount of saturated fat in your food and limit an item with a high percentage,” McInerney says.

Another helpful tip to keep in mind about the percent of daily value:

  • 20% or more of a nutrient (per serving) is considered high.
  • 5% or less of a nutrient (per serving) is considered low.

“These percentages reflect the latest scientific findings on the daily amounts of nutrients we should include in our diets,” she says. “You should look for foods that are low in saturated fat, trans fat and added sugars, while aiming to eat more foods that are high in vitamin D, calcium, iron, potassium and fiber.”

Tip 4: Review the amount of added sugars.

There are two types of sugars in the food you eat. The first occur naturally and are found in foods such as fruits and milk. The second, known as added sugars, do not occur naturally and are added to a product during processing.

“Added sugars do not provide nutritional benefits, and they can lead you to exceed the number of calories you eat during the day,” McInerney says. “Consuming too many added sugars is also linked to a wide range of health conditions, including obesity, type 2 diabetes, heart disease and certain types of cancer. It’s recommended you consume less than 10% of your daily calories from added sugars.”

The American Heart Association (AHA) recommends no more than 25 grams of added sugars per day for women and no more than 36 grams per day for men.

By understanding the information on food labels — like calories and added sugars — you can make better health decisions for you and your family.

Stephanie McInerney, a registered dietitian at Keck Medicine

Tip 5: Look at the vitamin D and potassium numbers.

Vitamin D and potassium were added to nutrition labels in 2016. These new additions are nutrients that Americans don’t get enough of, according to the FDA.

“Vitamin D and calcium are important to support bone health, while iron is key for your blood cells to carry oxygen. And potassium helps with nerve and muscle function, as well as a steady heartbeat.”

The National Institutes of Health recommend 15 micrograms of vitamin D a day for adults, and 3,400 milligrams of potassium a day for men and 2,600 milligrams for women.

Nutritional needs are not one-size-fits-all.

Learning how to read nutrition labels can be a useful tool in maintaining and improving your overall well-being. But McInerney also highlights the importance of understanding your own unique health needs.

“Everyone’s nutritional needs are different, and they can depend on many factors, including activity level, genetics, age and overall food intake, just to name a few,” she says.

“If you have questions about healthy eating habits, a registered dietitian can help you find the care that’s right for you,” McInerney says.

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Fanny Chavarria
Fanny Chavarria is a writer and editor for Keck Medicine of USC.

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