English Reference
adjective · noun

dietary

adj. · n.
US /ˈdaɪəˌtɛɹi/ UK /dˈaɪətəɹi/ di·etary UK spelling dietaries

  1. 01 B2 Upper Intermediate Medicine

    adj.relating to the food you eat or to a special diet you follow for health or religious reasons.

    adj.pertaining to the intake of food or to specific nutritional regulations and restrictions.

    Simple

    The restaurant menu clearly marks any dishes that meet common dietary requirements.

    In context

    The doctor suggested several dietary changes to help manage his high blood pressure without relying solely on medication.

    Usage

    Usually placed before a noun, such as 'dietary habits', 'dietary needs', or 'dietary fiber'.

    nutritionalalimentary
  2. 02 C2 Proficiency FormalTechnical

    n.a fixed plan for what people in a place like a hospital or prison should eat.

    n.a prescribed system or schedule of food provided to the inhabitants of an institution.

    Simple

    The hospital dietary was designed to provide patients with balanced nutrition during recovery.

    In context

    Historical records from the nineteenth-century prison show a strict dietary consisting largely of bread, gruel, and occasional servings of meat.

    Teacher's tip

    This noun sense is rare in modern conversation; learners will almost always encounter 'dietary' as an adjective.

    regimendietary plan

Usage dietary fiber

For many people, meat and dairy products are important dietary sources of B12.

ScienceDaily· 30 Aug 2026

In other words, ecology may have helped shape both dietary behavior and human biology.

ScienceDaily· 27 Aug 2026

From Medieval Latin diētārium (“book prescribing diet”), from Latin diaeta (“diet”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Latin diaeta
Level B2 · Upper Intermediate
Frequency Frequent
Updated