What's the first thing you should check on a food label?

October 19, 2025 •

6 min read

According to the U.S. Food and Drug Administration, the serving size and servings per container are found at the top of the Nutrition Facts label and are the first things you should check on a food label before anything else. This initial step is crucial for understanding how the rest of the label's information applies to your consumption.

Quick Summary

This article explains why the serving size and servings per container are the first things you should check on a food label. It details how this information impacts other nutritional data, provides a guide to reading the entire label, and contrasts different label components to help you make healthier, more informed food decisions.

Key Points

Check Serving Size First: The very first thing to look for is the serving size and servings per container, as all other nutritional data depends on it.
Don't Be Fooled by Calories: Calories listed on a label apply to a single serving. If you eat the entire package, you may consume significantly more calories than advertised.
Use the 5/20 Rule: The % Daily Value column helps quickly identify if a food is high (20% or more) or low (5% or less) in a nutrient, aiding in quick comparison.
Scan the Ingredients List: Ingredients are listed by weight, so the first few items tell you what the product is mostly made of. Check here for hidden sugars and other processed additives.
Be Skeptical of Marketing Claims: Don't trust front-of-package claims like 'low-fat' or 'healthy' without verifying the details on the Nutrition Facts panel.
Allergens Are Clearly Listed: For those with allergies, the ingredients list is crucial as allergens are typically listed in bold or a separate statement.
Compare Products Easily: Using the 'per 100g' or 'per 100ml' metric is an excellent way to compare the nutritional content of different products fairly.

Why Serving Size is the Most Important First Step

When you pick up a packaged food item, the very first numbers you should look for are the "Serving Size" and "Servings Per Container" located at the top of the Nutrition Facts panel. This initial glance is arguably the most critical step in evaluating a food product, as all other nutritional information, including calories, fat, and sugar content, is calculated based on this stated serving size. Ignoring this crucial detail can lead to a significant miscalculation of your actual intake.

For example, a product advertised as having a reasonable calorie count might actually contain two, three, or even four servings per container. If you consume the entire package without realizing this, you'll be consuming two to four times the calories, sodium, and fat listed per serving. This simple mistake can derail a diet or lead to unintended overconsumption of certain nutrients.

The Direct Impact of Serving Size

Understanding the serving size directly affects your interpretation of the entire label. It forces you to mentally adjust all subsequent numbers based on how much you realistically plan to eat. By starting here, you ground your nutritional assessment in reality rather than in a potentially misleading marketing claim on the front of the package. It's the foundational piece of information that makes all other details meaningful.

The Three Main Sections of a Food Label

Beyond the serving size, the food label is divided into several key areas that provide a comprehensive view of a product's nutritional profile. A savvy consumer will move systematically through these sections after checking the serving information.

The Nutrition Facts Panel: This is the core of the label. It details the calories, macronutrients (fat, carbohydrates, protein), and key micronutrients like vitamins and minerals per serving. The FDA-updated label, which is now on most products, includes added sugars and lists Vitamin D and potassium, as they are often under-consumed nutrients.
The Ingredients List: Found separately from the nutritional panel, this list details every single ingredient in the product, arranged in descending order by weight. The ingredients present in the largest amounts are listed first. This section is vital for those with food sensitivities, allergies, or dietary restrictions. It also reveals the presence of highly processed components, hidden sugars (like fructose or dextrose), or excessive additives.
Claims on the Packaging: These include marketing terms like "low-fat," "natural," or "high in fiber." While they can be helpful, it's essential to use them as a guide and verify the claim by cross-referencing it with the Nutrition Facts Panel and ingredient list. For instance, a "low-fat" product might still be high in sugar.

Comparing Two Common Snacks: Yogurt vs. Granola Bar

This table illustrates how to compare two products using the serving size as a starting point. We’ll compare a standard single-serving yogurt cup versus a single granola bar.


Feature	Single-Serving Yogurt (e.g., 150g)	Single Granola Bar (e.g., 40g)
First thing to check	Serving Size: 1 container (150g). Servings Per Container: 1.	Serving Size: 1 bar (40g). Servings Per Container: 1.
Calories	120 calories	170 calories
Added Sugars	7g	12g
Dietary Fiber	0g	3g
Protein	12g	4g
Ingredients	Cultured skim milk, cane sugar, pectin, natural flavors.	Granola (whole grain oats, brown sugar), corn syrup, rice flour, palm kernel oil, honey, soy lecithin.
Conclusion	Lower calories and added sugar, higher in protein. Good for a high-protein snack.	Higher calories and added sugar, but also provides dietary fiber. Contains more processed ingredients.

The Role of Percent Daily Value (%DV)

After checking the serving size and reviewing the nutrient list, the Percent Daily Value (%DV) is the next most useful tool on the label. The %DV tells you the percentage of the daily recommended amount of each nutrient that one serving provides, based on a 2,000-calorie diet.

There is an easy rule to follow: the "5/20 Rule".

5% DV or less is considered a low source of that nutrient. For nutrients you want to limit, like saturated fat, sodium, and added sugars, look for a low %DV.
20% DV or more is considered a high source of that nutrient. For nutrients you want to get more of, such as fiber, vitamins, and minerals, look for a high %DV.

Using the %DV allows you to make quick, easy comparisons between similar products to see which one better fits your dietary goals. It also helps you manage your total intake throughout the day. If a product contains 40% of your daily sodium, you'll know to choose lower-sodium options for the rest of your meals.

The Importance of the Ingredients List for Transparency

While the Nutrition Facts panel gives you the quantitative data, the ingredients list provides the qualitative story of your food. Ingredients are listed in descending order by weight, meaning the first ingredient makes up the largest proportion of the product. This is particularly revealing for highly processed foods. If a form of sugar or a refined grain is the first or second ingredient, it's a strong indicator that the food may not be as healthy as its marketing suggests.

For those with specific health concerns or allergies, the ingredients list is the final, non-negotiable step. Food manufacturers must clearly declare the presence of major allergens, typically in bold print or in a separate statement below the list. For instance, a product might state "Contains: Milk, Soy, Wheat."

Conclusion: Making Smarter Choices Starts at the Top

In conclusion, the first and most critical piece of information to check on a food label is the serving size and the number of servings per container. This simple action provides the context necessary to accurately interpret all other nutritional information. After establishing the serving size, a smart shopper will proceed to evaluate the nutrient profile, paying close attention to added sugars, saturated fat, and sodium. The ingredient list offers further insight into the quality and processing of the food. By consistently applying these simple steps, consumers can move beyond marketing claims and make truly informed, healthier choices for themselves and their families. This practice empowers you to take control of your diet and understand exactly what you are putting into your body. For more information on understanding food labels, consult the official U.S. Food and Drug Administration guidance at https://www.fda.gov/food/nutrition-facts-label/how-understand-and-use-nutrition-facts-label.

How to Read a Food Label Effectively

Start with serving size: Always check the serving size and how many servings are in the package to avoid misinterpreting the rest of the information.
Evaluate calories: Look at the calorie count per serving and multiply it by the number of servings you plan to eat.
Identify key nutrients: Pay attention to saturated fat, sodium, and added sugars, aiming for lower amounts. For beneficial nutrients like fiber, vitamins, and minerals, look for higher amounts.
Use % Daily Value: Remember the 5/20 rule. 5% DV is low, and 20% DV is high. This helps compare products quickly.
Scan the ingredients list: Check the first few ingredients to see what the product is primarily made of. Avoid products where sugar or processed ingredients are at the top.
Don't rely solely on claims: Marketing claims like "healthy" or "natural" can be misleading. Always check the Nutrition Facts panel to verify them.
Check for allergens: If you have allergies, always confirm that potential allergens are listed, usually in a clear, bold format below the ingredients.

Further Tips for Health-Conscious Consumers

Prioritize whole foods: Products with a short ingredients list containing recognizable items are generally less processed and healthier.
Compare similar items: Use the "per 100g" or "per 100ml" column to compare the nutritional content of similar products, as serving sizes can vary between brands.
Look beyond the label: While the label is a powerful tool, it doesn't tell the whole story. Consider the food's source and sustainability where possible.

Staying Informed and Making Better Choices

Reading a food label effectively is an important skill that empowers consumers to take charge of their health. By following a systematic approach that begins with checking the serving size, you can easily filter through marketing noise and access the factual nutritional information you need. This practice not only helps in managing weight and specific health conditions but also promotes a deeper understanding of food and nutrition.

Frequently Asked Questions

Checking the serving size first is crucial because all other nutritional information, including calories, fat, and sugar, is based on that amount. If you eat more than one serving, you must adjust all the other numbers accordingly to get an accurate picture of what you're consuming.

The '5/20 rule' is a quick guide based on the Percent Daily Value (%DV). A food with 5% DV or less of a nutrient per serving is considered low, while 20% DV or more is considered high. This allows for quick comparisons between products to help you choose foods with more of the nutrients you want and less of those you want to limit.

The ingredients list is crucial for identifying what a product is primarily made of. Ingredients are listed in descending order by weight, so the first few items are the most abundant. Look for whole foods and be cautious if sugar or highly processed ingredients appear at the top.

You should not rely solely on marketing claims like 'low-fat,' 'organic,' or 'healthy.' These claims can be misleading. Always verify them by checking the detailed information on the Nutrition Facts panel and the ingredients list.

Using the 'per 100g' or 'per 100ml' column is the fairest way to compare the nutritional content of similar products. Serving sizes can vary between manufacturers, so using a standardized amount ensures an accurate, apples-to-apples comparison.

Allergens are typically declared clearly and conspicuously on the food label, often in bold print or listed separately below the ingredients list. This is mandated by law to help people with food allergies avoid dangerous ingredients.

Total Sugars includes both naturally occurring sugars (like in milk and fruit) and added sugars. Added Sugars, however, only refers to sugars added during processing. Limiting your intake of added sugars is often a key nutritional goal.