Understanding Nutrition: When reading a food label, the first thing you should look at is the serving size.

October 31, 2025 •

4 min read

According to the U.S. Food and Drug Administration (FDA), all other nutritional values on a food label are tied to the specified serving size. Therefore, when reading a food label, the first thing you should look at is the serving information, as it provides the essential context for everything else you are about to read. This small but crucial step prevents misinterpreting calorie counts and nutrient levels, allowing for accurate tracking of your dietary intake.

Quick Summary

This article explains why focusing on serving size and servings per container is the essential first step to reading any food label accurately. It also details how to properly interpret calories, key nutrients, the ingredients list, and the percent Daily Value to make informed, healthy decisions.

Key Points

Serving Size is the Foundation: Always look at the serving size and servings per container first, as all other nutritional data is based on this amount.
Check Your Math: If you eat more than one serving, multiply all nutritional values accordingly to get an accurate count.
Limit the Big Three: Keep an eye on the % Daily Value for saturated fat, sodium, and added sugars, aiming for options with lower percentages.
Boost Your Beneficials: Look for products with higher % Daily Values for nutrients like dietary fiber, vitamin D, and potassium.
Analyze the Ingredients: The ingredients list, ordered by weight, reveals the main components of the food and helps identify hidden sugars or allergens.

The Crucial First Step: Serving Information

The serving information, found at the very top of the Nutrition Facts panel, is the foundation for all other data presented. This section contains two key pieces of information: the serving size and the servings per container. The serving size is a standardized amount, such as "1 cup" or "8 pieces," that reflects the portion typically consumed by people. However, it is not a recommendation for how much you should eat. The 'servings per container' tells you how many of those specified servings are in the entire package. A single-serving bag of chips might actually contain two or more servings, and assuming the entire bag is a single serving is a common mistake that can double or triple your calorie and nutrient intake unintentionally.

For example, if a package lists a serving size of 1 cup with 200 calories and the entire container holds 2 servings, eating the whole package means you've consumed 400 calories. By starting with this information, you can quickly determine how much you are truly eating and if it aligns with your health goals.

Deconstructing the Label, Section by Section

Once you understand the serving information, you can accurately interpret the rest of the label. The information is designed to help you make informed decisions, whether you're managing your weight or addressing specific health concerns like high blood pressure or cholesterol.

Limiting Nutrients of Concern

Below the calorie count, the label lists nutrients that many people consume in excess and should monitor, including saturated fat, sodium, and added sugars. Diets high in these components are associated with an increased risk of chronic diseases like cardiovascular disease. The % Daily Value (%DV) helps you determine if a serving is high or low in a particular nutrient: 5% DV or less is considered low, while 20% DV or more is considered high.

Seeking Beneficial Nutrients

Conversely, the label also highlights nutrients that Americans often do not get enough of, such as dietary fiber, vitamin D, calcium, iron, and potassium. Aim for foods with a higher %DV for these nutrients to support your overall health. Dietary fiber, for instance, can help lower cholesterol and promote feelings of fullness.

The Ingredients List

Located separately from the Nutrition Facts table, the ingredients list provides a comprehensive breakdown of what's in the product, with items listed in descending order of predominance by weight. This means the first ingredient makes up the largest portion of the food. This is especially useful for spotting added sugars, which can appear under many different names, such as sucrose, high-fructose corn syrup, or maltose. For those with allergies, the ingredients list is critical for checking allergens, which are often highlighted in bold.

A Comparison of Canned Soups

Let's compare two hypothetical canned soups to see how reading the label can influence your choice. Both cans are the same size.


Nutrient	Creamy Tomato Soup (per serving)	Healthy Heart Vegetable Soup (per serving)
Serving Size	1 cup (250g)	1 cup (250g)
Servings per container	2	2
Calories	240	120
Total Fat	12g	3g
Saturated Fat	7g (35% DV)	1g (5% DV)
Sodium	850mg (37% DV)	140mg (6% DV)
Dietary Fiber	2g (7% DV)	8g (29% DV)

In this example, if you are looking to limit your sodium and saturated fat intake, the Healthy Heart Vegetable Soup is the clear winner, despite having the same serving size. The Tomato Soup is high in both, while the Vegetable Soup is low in both and provides significantly more beneficial dietary fiber.

Making it a Habit: Tips for Quick Label Reading

To make the process of reading labels faster and more effective, focus on these areas:

Start with Serving Information: Always check the serving size and servings per container first to understand the context of all other values.
Scan for Red Flags: Quickly look for high percentages of saturated fat, sodium, and added sugars. Remember that 20% DV or more is considered high.
Prioritize the Positives: Seek out foods with a high %DV for fiber and other vitamins and minerals.
Review the Ingredients: Check the first three ingredients for an indication of the main components. For example, if sugar is a top ingredient, the product is high in sugar.
Use the %DV for Comparison: Use the %DV to compare similar products and find the healthier option. Just be sure the serving sizes are the same or adjust the comparison accordingly.

Conclusion: Your Roadmap to Healthier Choices

Mastering the art of reading food labels begins with a single, foundational step: checking the serving size. All other nutritional information, from calories to sodium to added sugars, is directly tied to that value. By first understanding the context of your portion, you can then move on to evaluating the key nutrients and ingredients, ultimately gaining the power to make more informed and healthy dietary decisions. This skill transforms the simple act of grocery shopping into a powerful tool for achieving your health and nutrition goals. It allows you to confidently compare products and choose foods that align with your wellness journey.

For more detailed guidance on decoding the Nutrition Facts label, visit the FDA's website.

Frequently Asked Questions

A serving size is a standardized, measured amount of food listed on the Nutrition Facts label. A portion size is the amount of food a person chooses to eat in one sitting.

The servings per container number tells you how many servings are in the whole package. This is crucial because many packages contain multiple servings, and consuming the whole package means you must multiply the nutrient values accordingly.

The %DV shows how much a nutrient in one serving contributes to a total daily diet. As a general guide, 5% DV or less is considered low for a nutrient, while 20% DV or more is considered high.

Not necessarily. While 'low-fat' means it has less fat than the original product, it might still contain high amounts of sugar or calories. It is always important to check the full Nutrition Facts panel to be sure.

Look at the ingredients list for added sugars, which may be listed under various names like sucrose, dextrose, high-fructose corn syrup, or corn syrup. Ingredients are listed by weight, so if a sugar is near the top, the product is likely high in it.

Compare the % Daily Value for key nutrients like sodium, saturated fat, and fiber on the Nutrition Facts panel, ensuring the serving sizes are comparable. Look for options with more beneficial nutrients and fewer less-desirable ones.

A 'contains' statement lists major food allergens present in the product, such as wheat, milk, or soy. This helps individuals with food allergies quickly identify ingredients they need to avoid.