Portion control is the systematic management of serving sizes in food service and retail, ensuring each customer receives a consistent, intended quantity. In professional kitchens it is enforced through portioning tools, scoops, scales, ladles, and count-based plating, and through specifications that define exact weights for proteins, starches, and accompaniments. The purposes are multiple: cost control, since food cost percentages depend on consistent portions; nutritional consistency for labelled values and special diets; fairness to customers; and waste reduction. In packaged foods, portion control appears as single-serve packs, individually wrapped butter portions, and multipacks that pre-divide snacks. Public health has embraced the principle against the tide of supersizing: smaller default portions, as in reduced-size confectionery and the UK’s sugar reduction programme, nudge consumption down without demanding willpower.