Estimating dietary costs of low-income women in California: a comparison of 2 approaches

Abstract

Background: Currently, no simplified approach to estimating food costs exists for a large, nationally representative sample. Objective: The objective was to compare 2 approaches for estimating individual daily diet costs in a population of low-income women in California. Design: Cost estimates based on time-intensive method 1 (three 24-h recalls and associated food prices on receipts) were compared with estimates made by using less intensive method 2 [a food-frequency questionnaire (FFQ) and store prices]. Low-income participants (n = 121) of USDA nutrition programs were recruited. Mean daily diet costs, both unadjusted and adjusted for energy, were compared by using Pearson correlation coefficients and the BlandAltman 95% limits of agreement between methods. Results: Energy and nutrient intakes derived by the 2 methods were comparable; where differences occurred, the FFQ (method 2) provided higher nutrient values than did the 24-h recall (method 1). The crude daily diet cost was $6.32 by the 24-h recall method and $5.93 by the FFQ method (P = 0.221). The energy-adjusted diet cost was $6.65 by the 24-h recall method and $5.98 by the FFQ method (P , 0.001). Conclusions: Although the agreement between methods was weaker than expected, both approaches may be useful. Additional research is needed to further refine a large national survey approach (method 2) to estimate daily dietary costs with the use of this minimal time-intensive method for the participant and moderate time-intensive method for the researcher.Am J Clin Nutr 2013;97:835-41.

Contribution of food prices and diet cost to socioeconomic disparities in diet quality and health: a systematic review and analysis

“… 78 Another study also found relatively weak agreement between diet costs estimated with standard prices and with prices actually paid by individuals. 93 …”

Comparability of methods assigning monetary costs to diets: derivation from household till receipts versus cost database estimation using 4-day food diaries

“…Aaron et al 13 similarly found a relatively small mean difference of $0.14 between the two methods that they compared, with 95% limits of agreement of over $7.00. This compared with a mean diet cost of around $6.00 using either method.…”

“…12 In contrast, our study compares two different diet cost methods. The study by Aaron et al 13 also compared different diet cost methods, but used a frequency questionnaire to assess dietary intake, whereas this study was based on cost estimates from 4-day diet diaries. As such, this study should assist researchers in interpreting estimates of diet cost provided by such databases when applied to diet diaries.…”

“…A previous study has assessed the level of agreement between costs as estimated using a price database from different dietary assessment tools. 12 In addition, a recently published study 13 examined the agreement between cost estimates obtained by assigning prices to a frequency questionnaire and those obtained from till receipts alongside 24-hour recalls. However, to the best of our knowledge, this study is the first to compare diet costs from till receipts with food diaries.…”

Assessing healthy diet affordability in a cohort with major depressive disorders

“…FFQs typically lack specific detail regarding serving sizes, such that this information is often based on standardised portion sizes of specific foods published in National dietary guidelines (Vlismas et al, 2010), which does not account for individual variation (Rangan et al, 2009). Other studies use self-reported 24 h recall (Aaron et al, 2013) or dietary histories in a face-to-face interview (Turrell and Kavanagh, 2005), which are prone to recall bias and poor reliability at the individual level (Thomas B, 2002). Few studies use 7-day diet records (Rao et al, 2013), commonly referred to as the 'gold standard' dietary assessment tool (Hoidrup et al, 2002).…”