Dietary intake assessment - Direct observation

direct observation image

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Population of Interest (P=Parent, R=Researcher, C=Child)

  • Age: <1 yr (R or P); 1-10 yrs (R or P); 3-5 yrs (R or P); 10-12 yrs (R or P); 12 yrs+ (R or P)
  • Setting: Home; Community
  • Administration Method: Nil

Direct observation

This method is quite resource intensive but involves trained researchers directly observing a participant's food intake and behaviours to ascertain foods, brands and portions consumed. This may or may not be within a research environment and it is often preferable if a participant is not able to identify who the observer is so they do not alter their dietary intake.


Direct observation can be used to provide an objective measure of an individuals' dietary intake or to validate another dietary assessment method.

When to Use

Useful to collect detailed information on food intake and behaviours, not for assessment of an individuals' intake.


Limited dietary assessment, but energy intake seems biased towards over-estimation, with greater over-estimation in children under 9 years. This method lacks precision at the individual level.


Low participant burden but high researcher burden as time needs to be allocated to actual observation of participants.

Considerations (miscellaneous)

Expensive due to the amount of time required to observe participants in their eating environments.

A method of quality assurance should be employed with this method, particularly if a number of researchers are being used to collect information from different sites. Standardised data tools detailing the information to be collected should be used.


Objective measure and does not rely on ones’ memory.


  • Skilled staff required to conduct the interview
  • Labour and time intensive,
  • High respondent burden.

Participants may alter their usual intake due to observation and could be perceived as an invasive method. The method is usually too imprecise to obtain valid measures of an individuals' intake.