What is the requirement for a product to be labeled as "trans-fat-free"?

For a product to be labeled as "trans-fat-free," it can contain fewer than 0.5 grams of trans fats per serving. This guideline originates from the regulations established by the Food and Drug Administration (FDA), which allows products with this low level of trans fats to be marketed with the "trans-fat-free" label. The rationale behind this is that the small amount of trans fats is considered negligible in the context of a diet. Therefore, foods that contain less than this threshold can still effectively be categorized as free of trans fats for practical purposes, making it easier for consumers to make healthier dietary choices.

The other options imply stricter definitions which do not align with established labeling guidelines. Hence, fewer than 0.5 grams per serving is the standard that correctly fits the requirement for the trans-fat-free label.