What is meant by 'special dietary need'?

A 'special dietary need' refers specifically to an individual's nutritional requirements that arise from health conditions, allergies, or intolerances. This definition encompasses the need for specialized foods or dietary modifications to prevent adverse health effects. For example, someone with celiac disease cannot consume gluten, and thus requires a strictly gluten-free diet. Individuals with food allergies, such as nut allergies, also have special dietary needs, as exposure to allergens can lead to serious health risks.

In terms of the other options, a preference for vegetarian food indicates a choice rather than a necessity based on health or allergies. General food preferences relate to personal taste and do not necessarily involve medical or health-related requirements. Meal customization by the chef can enhance a dining experience but does not inherently address the specific health-based dietary requirements that characterize special dietary needs. Hence, the emphasis on health-related conditions and allergies solidifies the appropriateness of the selected answer.