Start with the portion in grams, then compare calories, added sugars, saturated fat and any nutrients important to you. A darker bar, a smaller serving printed on the wrapper or a higher cacao percentage answers only part of that comparison.
Read the nutrition panel in a useful order
On a US Nutrition Facts label, the serving size describes an amount people typically consume; it is not an instruction for how much you personally should eat. Check servings per package, especially when a bar looks like a single portion. FDA’s label guide explains how the numbers scale with the amount eaten.
- Record the labeled serving weight in grams.
- Read calories, added sugars and saturated fat for that weight.
- Check fiber, protein or minerals if those matter to your comparison.
- Use the same gram amount for each product, then repeat for the portion you expect to eat.
Total sugars includes naturally occurring and added sugars. Added sugars is a subset, so adding those two lines together double-counts some sugar. FDA’s added-sugars explanation also describes how milk’s naturally occurring sugar differs from sweeteners added during manufacture.
Compare equal weights before comparing pieces
A hypothetical pair of labels
The following values are invented to demonstrate arithmetic. They are not a database comparison, a brand claim or a ranking of dark versus milk chocolate.
Scroll the table sideways. With a keyboard, focus it and use the arrow keys.
| Measure | Product A: label per 30 g | Product B: label per 20 g | A calculated per 20 g |
|---|---|---|---|
| Calories | 180 kcal | 110 kcal | 120 kcal |
| Added sugars | 9 g | 10 g | 6 g |
| Saturated fat | 6 g | 3 g | 4 g |
For A, multiply each labeled value by 20 ÷ 30, or two-thirds. At equal weight, A has less added sugar in this example but more saturated fat and calories. Choosing between them involves a priority, not a single winning number.
If you actually eat 15 g of A, multiply its 30 g label values by one-half: 90 kcal, 4.5 g added sugars and 3 g saturated fat. Keep the distinction between comparison weight and portion eaten. The same calculation works for any label: amount for your portion = labeled amount × your grams ÷ labeled serving grams.
Use the label-comparison worksheet to record two real packages. Keep sensible precision; label rounding means calculated decimals are approximations.
Use percentages and claims carefully
FDA’s general label rule treats 5% Daily Value or less as low and 20% or more as high for a nutrient per serving. Daily Values are reference amounts for labeling, not a personalized nutrition prescription. A 2,000-calorie reference should not be mistaken for everyone’s energy needs.
Cacao percentage counts cacao-derived ingredients, including cocoa butter. It does not directly state added sugar, fiber or flavanol content. A filled bar also brings its filling into the nutritional picture. Compare the complete product rather than assuming that all 70% bars, truffles or cocoa drinks share one profile.
“No added sugar” and “sugar-free” describe particular attributes; read the remaining nutrients and ingredients as well. Polyols, intense sweeteners or other ingredients can produce a very different food from the bar you started with. If you need a product for an allergy or other dietary restriction, check the current package and manufacturer details for that exact item.
Separate a food choice from a health conclusion
A laboratory measurement of antioxidant activity is a different endpoint from changes in blood pressure or heart-disease events in people. In 2023, the FDA’s qualified cocoa-flavanol claim was limited to specified high-flavanol cocoa powder and foods containing it, with explicitly limited evidence. It did not extend to ordinary chocolate.
Use chocolate’s label to understand what you are eating and the research article to understand what was tested. For a dietary plan tied to a health condition, bring the label and your usual portion to the clinician or dietitian helping you. The dedicated blood-pressure guide below explains the evidence without turning a study dose into a daily chocolate target.