Dietary intake in hospitals: A systematic literature review of the validity of the visual estimation method to assess food consumption and energy and protein intake

Abstract

Background: Accurate dietary assessment is an essential component for nutrition care planning and monitoring. The visual estimation method (VEM) of dietary assessment is routinely used in hospitals around the world. Therefore, clarity regarding its validity is imperative.

Aim: To conduct a systematic literature review to evaluate the validity of the VEM to assess food consumption and energy and protein intake in the hospital setting.

Methods: This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement and checklist. Full-text manuscripts, published in English between January 2000 and September 2021, were searched using five electronic databases. A further manual search of reference lists was conducted.

Results: 14 studies evaluating the validity of 12 different VEMs were included. 12 studies used various point-scales (0-100%), three with pre-determined nutrient estimates assigned to each intake level, and nine without. Two studies used modern technology. Results indicate that the VEM can achieve validity at the group level, but support at the individual level was limited. No one method of visual estimation appeared to be more valid than another; however, training of raters appears to be important.

Conclusion: The VEM shows potential as a valid tool for dietary monitoring in hospitals. Further high-quality research is required to establish the effects of meal and rater characteristics on validity at the group and individual levels. Furthermore, to reflect current modes of implementation more fully, research is needed to evaluate the validity of the VEM when operated via food-service software suites.

Keywords: Dietary assessment; Energy intake; Hospitals; Systematic review; Validation; Visual estimation method.