Healthy eating is the practice of habitually choosing foods that supply the essential nutrients the body needs, in proportions matching dietary guidelines — plenty of vegetables, fruit, and whole grains; adequate protein from varied sources; limited saturated fat, salt, and added sugars; and energy intake matched to expenditure. It is a pattern, not a prescription: Mediterranean, Nordic, and traditional Asian diets all qualify despite looking quite different. The evidence for its benefits — lower risks of heart disease, type 2 diabetes, certain cancers, and obesity — is among the strongest in nutrition science. Public health promotes it through guidelines, labelling, school meals, and reformulation — while recognising that price, access, and culture shape what people actually eat.