A serving size is a standardized reference amount used to present nutrition information. A portion is the amount you choose or enter for a meal.
Feed Love keeps the two concepts separate: recipe yield controls per-serving totals, while ingredient quantities determine the recipe itself.
When an ingredient amount is missing, Feed Love labels the standard portion it assumed so you can replace it with the amount you actually used.
A useful workflow is to begin with the quantity you actually cooked or served, then change the recipe yield separately. That keeps ingredient totals and per-serving totals from being mixed together.
For shared dishes, a serving is best treated as a transparent calculation choice rather than a claim about how much any individual person should eat.