Preventive describes actions taken to stop something happening, particularly to prevent disease or infection from occurring or spreading. In nutrition and public health, preventive measures include folic acid fortification to prevent neural tube defects, iodised salt against iodine deficiency disorders, vaccination-like supplementation campaigns, and dietary guidance to prevent chronic disease. In food safety, the entire HACCP system is preventive by design: identifying hazards and controlling them before food reaches consumers, rather than testing finished products and hoping. The preventive principle also underlies hygiene practice, from handwashing to temperature control, each step preventing contamination or growth rather than remedying it. Prevention is invariably cheaper and kinder than cure, whether the currency is birth defects avoided, outbreaks averted, or chronic disease delayed by decades of healthy eating.