Acceptable daily intake: Estimate of the amount of a substance in food or drinking water, expressed on a body mass basis (usually mg/kg body weight), which can be ingested daily over a lifetime by humans without appreciable health risk. For calculation of the daily intake per person, a standard body mass of 60 kg is used. The acceptable daily intake is normally used for food additives (tolerable daily intake is used for contaminants). Abbreviated ADI.