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Nutrition 101: How to Read and Use Food Labels

Oct 8, 2021
By Michelle Konstantinovsky
Woman reading nutrition label on dairy product at the grocery store

Clinical Editor: Michael Richardson, MD

You’ve likely seen it a million times as you’ve perused the grocery store shelves, contemplated convenience store snack options, and wondered whether a seemingly wholesome food is really all it’s cracked up to be. But while many of us may have received a crash course on those ubiquitous nutrition labels in middle school health class, few can say they’ve fully retained all the info into adulthood. If you’ve been struggling to make sense of the terms, totals, percentages, and more printed on your packaged foods, here’s a quick refresher to help you make more informed nutrition choices:

Understanding the overall point of label

If you’re wondering who’s responsible for the standardized nutrition label in the first place, look no further than the Food and Drug Administration (FDA). The federal agency first published regulations requiring nutritional labeling of certain foods in 1973, and the information required on the label has evolved over time. Generally speaking, the point of the nutrition label is to help consumers make quick, educated food decisions and ultimately, to opt for healthier options when possible.

The information in the main section of each nutrition label can vary depending on the food or beverage displaying it, but consumers will typically find everything from the product’s serving size and calories to its specific nutrient information. The far right section of the label typically contains a footnote that explains the “% Daily Value” (%DV).

Let’s break down some of the main parts of the nutrition label.

Serving size

Perhaps the trickiest part of picking apart a nutrition label is understanding the purpose of the first piece of info — the “serving size.” If you’ve ever eaten an entire bag of chips in one sitting, assuming the nutrition stats on the label applied to the whole bag, only to find the whole bag contained multiple servings, then you’re already familiar with this concept.

The point of the serving size isn’t necessarily to trick consumers into accidentally overeating; it’s to offer some standardized measurement that makes it easier to compare the item in question to other similar foods. That’s why a serving isn’t always indicated by a “bag” or a “box,”; it’s measured in units, like cups or pieces, followed by the metric amount, e.g., the number of grams (g). The serving size is not a written-in-stone recommendation of how much you should eat or drink. Only you and your healthcare team can determine the right amount for you and your needs.

The serving size is important because all the nutrient amounts that follow it on the label — including the number of calories — are based on the size of the serving. So if, for example, a chocolate bar’s nutrition label proclaims “170 calories,” be sure to reference the serving size if calories are a concern for you — that number may indicate the total amount in just a fraction of the bar, not the whole bar itself. A 3.3 ounce DOVE® silky-smooth dark chocolate bar, for example, contains three servings, meaning if you consume the whole thing, you’ll be consuming three 170-calorie servings, or 510 calories.


The word “calorie” has become a loaded term in cultural conversations around food, weight, nutrition, and more, but at the end of the day, a “calorie” is a measurement of how much energy you get from a serving of food. While the FDA uses a 2,000-calorie daily allowance as a reference point for nutrition labels, each and every individual has different caloric needs. The amount of calories you need to live a healthy life may differ greatly from this general range. There are online tools to estimate your daily caloric needs, but if you have a health issue that may be influenced by calories (e.g. diabetes), it’s best to work with your primary care provider, nutritionist, dietitian, or specialist to create a personalized plan that works for you.

Total fat

The nutrition label also includes a line for “total fat.” Like protein and carbohydrates, fat is a macronutrient, aka the nutrients your body uses in the largest amounts. All three macronutrients are essential for optimal health, but fat has historically gotten a bad rap. While carbohydrates are broken down into sugar, starch, and fiber on the label (more on that later), and protein is presented in total grams, total fat is usually broken down into quantities of saturated fat, trans fat, and monounsaturated and polyunsaturated fat. Saturated fat is the type of fat that’s more often found in animal products and is usually solid at room temperature. Saturated fats are not evil and do not need to be eliminated from your diet, but the American Heart Association recommends limiting saturated fats to reduce the risk of heart disease. Trans fat occurs naturally in small amounts in dairy products, beef, and lamb, but is most notably found in higher quantities in artificially-made foods, such as pie crusts, pizza, margarine and other spreads. Eating large amounts of trans fats were found to significantly increase one’s risk of heart disease, which is why in 2018, most uses of partially hydrogenated oils (which include artificial trans fat) have been phased out. Monounsaturated and polyunsaturated fats are found more often in plant-based foods and are usually liquid at room temperature as oils (think: avocados, salad dressings, nuts, olives, vegetable oils, etc.). They are recommended to be your primary source of fats as they can lower your risk of heart disease and stroke, while also supporting your body’s cells and providing a good source of vitamin E.

While again, everyone’s dietary needs are different, the FDA does cite evidence indicating that diets higher in saturated fat and trans fat are associated with increased levels of total

cholesterol and low-density lipoprotein (LDL or “bad”) cholesterol. This type of cholesterol has been associated with an increased risk of developing cardiovascular disease, so the agency recommends consuming less than 10% of calories per day from saturated fat and keeping the intake of trans fat as low as possible by limiting food sources of the artificial variety of trans fat.


The bulk of the nutrition label is dedicated to breaking down a food or beverage product’s different types of nutrients, like fat, sodium, and added sugars, that can have an impact on your health. For example, too much saturated fat and sodium in your diet is associated with an increased risk of developing some health conditions, like heart disease and high blood pressure. This is why experts have provided guidelines on “healthy” recommended amounts for the average person. That said, everyone’s individual nutritional needs are different, so it’s best to work with a nutritionist or dietician if you have a health condition that is strongly influenced by your diet.

A note on sugar: you may have noticed that nutrition labels include a few different categories for sugar. “Added sugars” refers to sugars like sucrose or dextrose that are added during the processing of certain foods, foods that are packaged as sweeteners themselves (like table sugar), sugars from syrups and honey, and sugars from concentrated fruit or vegetable juices. According to the FDA, “diets high in calories from added sugars can make it difficult to meet daily recommended levels of important nutrients while staying within calorie limits.” Total sugars, on the other hand, includes any added sugars that may be present in a product, as well as any sugars that are naturally present, like the sugar in milk and fruit. While there’s no established daily reference value for the total sugar an individual should consume, many experts agree that limiting the amount of added sugars in your diet is generally a positive thing. If you need to satisfy your sweet tooth, choosing a food with natural sugars, like fruit, is the best option when consumed in moderation.

The nutrients listed on the nutrition label aren’t all just ones to limit or avoid, however. Labels also include values for dietary fiber, vitamin D, calcium, iron, and potassium — nutrients that Americans may not get enough of and that have been identified as beneficial to overall health (but again, each person’s needs are different). For example, eating a diet high in dietary fiber has been shown to improve digestive regularity and lower blood sugar and cholesterol levels, while diets higher in vitamin D, calcium, and iron may reduce the risk of developing osteoporosis and anemia. You’ll also find information on protein and carbohydrate content on nutrition labels, which may help guide your choices if you’re looking to add or reduce specific nutrients to your diet.

The Percent Daily Value (%DV)

The % Daily Value (%DV) portion of the nutrition label includes percentages for the daily values of each nutrient in a serving of a food or beverage. The Daily Values are reference amounts expressed in grams, milligrams, or micrograms of nutrients to consume or not to exceed each day. The %DV indicates how much a nutrient in a serving of a food contributes to a total daily diet and is meant to help you determine whether a serving of food is high or low in a particular nutrient (5% DV or less of a nutrient per serving is considered low while 20% DV or more of a nutrient per serving is considered high). Very generally speaking, the FDA recommends choosing foods that are higher in %DV for dietary fiber, vitamin D, calcium, iron, and potassium, and opting for foods lower in %DV for saturated fat, sodium, and added sugars.

While there’s no need to obsess over the %DV (or any piece of info on the nutrition label, for that matter), understanding its significance may help you avoid falling for false or unsubstantiated marketing claims from food manufacturers. For example, if a brand uses terms like “light,” “natural,” “enriched,” etc., those words alone don’t mean much. Becoming familiar with food labels, along with your own nutritional needs, can help you analyze whether those terms are just catchy buzzwords used to sell more products or whether the food in question is actually chock-full of good-for-you nutrients.

The final takeaway

At the end of the day, the nutrition label is really just one more tool that can help you stay informed and educated about the choices you make around your health. But overall wellness is about more than calories, fat grams, and daily values. To make the most of the nutrition label and to achieve a more comprehensive picture of health, it's important to reflect on your health needs and goals to determine the best nutrition options for you. Book an appointment with a primary care care provider today

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Michelle Konstantinovsky

Michelle Konstantinovsky is an experienced writer, regularly producing content on a variety of wellness-oriented topics ranging from breaking health news to fitness and nutrition. Michelle has a master’s degree from UC Berkeley’s Graduate School of Journalism and has written extensively on health and body image for outlets like O: The Oprah Magazine, Slate, SPIN.com, xoJane.com, and The Huffington Post. To read more of her work, visit www.michellekmedia.com.

The One Medical blog is published by One Medical, a national, modern primary care practice pairing 24/7 virtual care services with inviting and convenient in-person care at over 100 locations across the U.S. One Medical is on a mission to transform health care for all through a human-centered, technology-powered approach to caring for people at every stage of life.

Any general advice posted on our blog, website, or app is for informational purposes only and is not intended to replace or substitute for any medical or other advice. 1Life Healthcare, Inc. and the One Medical entities make no representations or warranties and expressly disclaim any and all liability concerning any treatment, action by, or effect on any person following the general information offered or provided within or through the blog, website, or app. If you have specific concerns or a situation arises in which you require medical advice, you should consult with an appropriately trained and qualified medical services provider.