Measuring diet cost at the individual level: a comparison of three methods

Cost-effectiveness of protein-rich meals and snacks for increasing protein intake in older adults

OBJECTIVES

To investigate the cost-effectiveness of protein-rich meals and snacks for increasing protein intake in home-dwelling older adults.

DESIGN

Cost effectiveness analysis from a randomized controlled trial, the Power Meals study.

SETTING

Participants were randomized into one of three groups for eight weeks: a protein-rich meal, snack and bread (Protein), a regular meal (Normal) and a control group without meal service (Control).

PARTICIPANTS

Home-dwelling home care clients, caregivers and care recipients aged ≥65 years (n = 65).

MEASUREMENTS

Protein intake was assessed by a three-day food diary at the end of the study. Cost for the daily diet was estimated by using Finnish grocery store databases and the prices of the food service. The cost-effectiveness was assessed by an incremental cost-effectiveness ratio (ICER).

RESULTS

Costs for the daily diet in the Protein (8.35 €/d) and the Normal (7.94 €/d) groups were significantly higher than in the control group (5.65 €/d) (p < 0.001). Incremental cost-effectiveness analysis showed that increasing protein intake was cost-effective in the Protein group as incremental cost-effectiveness ratio was 8.11 in the Protein, 8.72 in the Normal and 6.45 in the Control group.

CONCLUSIONS

Including protein rich meals and snacks in a diet increases protein intake in home-dwelling older adults cost-effectively.

Adherence to the EAT-Lancet index is associated with lower diet costs in the Mexican population

BACKGROUND

Poor diet quality contributes to morbidity and mortality and affects environmental sustainability. The EAT-Lancet reference diet offers a healthy and sustainable solution. This study aimed to estimate the association between diet cost and dietary quality, measured with an EAT-Lancet Index.

METHODS

An EAT-Lancet index was adapted to assess adherence to this dietary pattern from 24-h recalls data from the 2012 and 2016 Mexican National Health and Nutrition Surveys (n = 14,242). Prices were obtained from the Consumer Price Index. We dichotomized cost at the median (into low- and high-cost) and compared the EAT-Lancet index scores. We also used multivariate linear regression models to explore the association between diet cost and diet quality.

RESULTS

Individuals consuming a low-cost diet had a higher EAT-Lancet score than those consuming a high-cost diet (20.3 vs. 19.4 from a possible scale of 0 to 42; p < 0.001) due to a lower intake of beef and lamb, pork, poultry, dairy, and added sugars. We found that for each one-point increase in the EAT-Lancet score, there was an average decrease of MXN$0.4 in the diet cost (p < 0.001). This association was only significant among low- and middle-SES individuals.

CONCLUSIONS

Contrary to evidence from high-income countries, this study shows that in Mexico, adhering to the EAT-Lancet reference diet is associated with lower dietar costs, particularly in lower SES groups. These findings suggest the potential for broader implementation of healthier diets without increasing the financial burden.

Cost of a Healthy Diet: A Population-Representative Comparison of 3 Diet Cost Methods in Canada

BACKGROUND

Different food price sources and dietary assessment tools may impact the estimation of diet costs and hamper our understanding of the relationship between diet costs and dietary intakes.

OBJECTIVES

We aimed to investigate the effect of 3 diet cost derivation methods, with increasing numbers of food prices and geographic specificity, holding consistent the dietary assessment tool, on the estimation of diet costs overall and by food group.

METHODS

We matched 24-h dietary recall data from the 2015 Canadian Community Health Survey-Nutrition (CCHS-N) to food price data from 3 Canadian Consumer Price Index (CPI) food price lists; national short list, national long list, and provincial long list. We compared the daily ($/day) and energy-adjusted ($/2000 kcal) diet costs overall and by food groups for the overall population (4+), children (4-18), and adults (19+).

RESULTS

The proportion of dietary intakes (grams) that were covered by CPI prices significantly increased from the national short list to the national long list but did not significantly differ from the national long list to the provincial long list. The national short list resulted in the highest daily and energy-adjusted diet costs overall. No difference in diet costs was noted between the national and provincial long lists. Diet costs for 4 food groups-additions, sweets, fruits, and vegetables, which were poorly covered by the national short list-significantly differed using the national and provincial long lists. All 3 diet cost methods were significantly correlated with energy intakes; however, a strong/very strong correlation was detected for children, and a weak/moderate correlation for adults.

CONCLUSIONS

The choice of food price data may introduce bias in the diet cost estimate, as well as limiting our understanding of how individuals allocate their diet costs. Refinement of diet cost estimation methodology and measures can strengthen future studies of how consumers allocate their purchases to their diets.

The dynamics in food selection stemming from price awareness and perceived income adequacy: a cross-sectional study using 1-year loyalty card data

BACKGROUND

Higher cost of healthy foods may explain unhealthy dietary patterns in lower-income households. Unfortunately, combining food selection and nutrient intake data to price and expenditure is challenging. Food retailer's customer loyalty card data, linked to nutrient composition database, is a novel method for simultaneous exploration of food purchases, price, and nutrition.

OBJECTIVES

We studied the associations between perceived income adequacy (PIA) as a grouping variable with price (per kilogram or megajoule) and the volume of purchases (percentage of expenditure or energy) simultaneously as outcome variables for 17 most purchased food groups.

METHODS

We used 1-year (2018) loyalty card data from the largest grocery chain in Finland. Participants were 28,783 loyalty cardholders who made ≥41% of food purchases from the retailer and answered an online questionnaire at the midpoint of data collection. The 5-level PIA described the perceived financial situation in the household. Energy and nutrient content of foods purchased were from the Finnish Food Composition Database Fineli. We calculated the Nutrient Rich Food Index per 100 g food using 11 nutrients. Trends in prices and expenditures between PIA levels were analyzed using 2-sided Jonckheere-Terpstra tests, with false discovery rate control (Benjamini-Hochberg method) and confounder adjustments (inverse probability weighting).

RESULTS

Lower PIA participants selected cheaper foods per kilogram and megajoule within most food groups. They also favored unhealthy food groups cheap in energy [<1 € (USD 1.18)/MJ]. Despite lower purchase price, the expenditure (%) among lower PIA was higher on alcohol, snacks, sugar-sweetened beverages, and sweets and chocolates.

CONCLUSIONS

Participants with lower PIA showed stronger price awareness. It is crucial to consider the pricing of competing alternative food groups, when steering toward environmentally sustainable and healthier food purchases. Package labeling might also direct the selection of healthier choices among the less expensive items within a food group.

Vegan Diet and Food Costs Among Adults With Overweight: A Secondary Analysis of a Randomized Clinical Trial

This secondary analysis of a randomized clinical trial investigates the effects of a vegan diet on total food costs per day.

Food insecurity is associated with glycemic markers, and socioeconomic status and low-cost diets are associated with lipid metabolism in Mexican mothers

The association between socioeconomic status (SES) and chronic disease has recently become more evident in middle- and low-income countries. We hypothesized that poor socioeconomic conditions, such as food insecurity, low educational level, or low SES, may restrict access to a healthy diet and may be associated with cardiometabolic risk independently of body fat. This study examined the relation between socioeconomic indicators, body fat, and cardiometabolic disease risk markers in a random sample of mothers living in Queretaro, Mexico. Young and middle-aged mothers (n = 321) answered validated questionnaires to determine SES, food insecurity, and educational level and a semiquantitative food frequency questionnaire to determine dietary patterns and the cost of individual diet. Clinical measurements included anthropometry, blood pressure, lipids profile, glucose, and insulin. Obesity was present in 29% of the participants. Women with moderate food insecurity had higher waist circumference, glucose, insulin, and homeostasis model assessment of insulin resistance than women with food security. High triglyceride concentration and lower levels of high-density lipoprotein and low-density lipoprotein cholesterol were associated with lower SES and lower educational level. Women who consumed a lower carbohydrate diet had higher SES, higher education, and better cardiovascular risk markers. The higher carbohydrate diet profile was the least expensive diet. There was an inverse association between the cost and energy-density of foods. In conclusion, food insecurity was associated with glycemic control markers, and lower SES and education were related to a low-cost, higher carbohydrate diet and to a greater cardiovascular risk. The influence of the social environment on obesity and cardiovascular diseases needs to be further explored.

Economic and health impacts of the Change4Life Food Scanner app: Findings from a randomized pilot and feasibility study

Introduction

The UK Government developed the Change4Life Food Scanner app to provide families with engaging feedback on the nutritional content of packaged foods. There is a lack of research exploring the cost-effectiveness of dietary health promotion apps.

Methods

Through stakeholder engagement, a conceptual model was developed, outlining the pathway by which the Food Scanner app leads to proximal and distal outcomes. The conceptual model informed the development of a pilot randomized controlled trial which investigated the feasibility and acceptability of evaluating clinical outcomes in children and economic effectiveness of the Food Scanner app through a cost-consequence analysis. Parents of 4–11 years-olds (n = 126) were randomized into an app exposure condition (n = 62), or no intervention control (n = 64). Parent-reported Child Health Utility 9 Dimension (CHU9D) outcomes were collected alongside child healthcare resource use and associated costs, school absenteeism and parent productivity losses at baseline and 3 months follow up. Results for the CHU9D were converted into utility scores based on UK adult preference weights. Sensitivity analysis accounted for outliers and multiple imputation methods were adopted for the handling of missing data.

Results

64 participants (51%) completed the study (intervention: n = 29; control: n = 35). There was a mean reduction in quality adjusted life years between groups over the trial period of –0.004 (SD = 0.024, 95% CI: –0.005; 0.012). There was a mean reduction in healthcare costs of –£30.77 (SD = 230.97; 95% CI: –£113.80; £52.26) and a mean reduction in workplace productivity losses of –£64.24 (SD = 241.66, 95% CI: –£147.54; £19.07) within the intervention arm, compared to the control arm, over the data collection period. Similar findings were apparent after multiple imputation.

Discussion

Modest mean differences between study arms may have been due to the exploration of distal outcomes over a short follow-up period. The study was also disrupted due to the coronavirus pandemic, which may have confounded healthcare resource data. Although measures adopted were deemed feasible, the study highlighted difficulties in obtaining data on app development and maintenance costs, as well as the importance of economic modeling to predict long-term outcomes that may not be reliably captured over the short-term.

Clinical trial registration

https://osf.io/, identifier 62hzt.

Assessing the Cost of Healthy and Unhealthy Diets: A Systematic Review of Methods

PURPOSE OF REVIEW

Poor diets are a leading risk factor for chronic disease globally. Research suggests healthy foods are often harder to access, more expensive, and of a lower quality in rural/remote or low-income/high minority areas. Food pricing studies are frequently undertaken to explore food affordability. We aimed to capture and summarise food environment costing methodologies used in both urban and rural settings.

RECENT FINDINGS

Our systematic review of high-income countries between 2006 and 2021 found 100 relevant food pricing studies. Most were conducted in the USA (n = 47) and Australia (n = 24), predominantly in urban areas (n = 74) and cross-sectional in design (n = 76). All described a data collection methodology, with just over half (n = 57) using a named instrument. The main purpose for studies was to monitor food pricing, predominantly using the 'food basket', followed by the Nutrition Environment Measures Survey for Stores (NEMS-S). Comparatively, the Healthy Diets Australian Standardised Affordability and Price (ASAP) instrument supplied data on relative affordability to household incomes. Future research would benefit from a universal instrument reflecting geographic and socio-cultural context and collecting longitudinal data to inform and evaluate initiatives targeting food affordability, availability, and accessibility.

Some Ultra-Processed Foods Are Needed for Nutrient Adequate Diets: Linear Programming Analyses of the Seattle Obesity Study

Typical diets include an assortment of unprocessed, processed, and ultra-processed foods, along with culinary ingredients. Linear programming (LP) can be used to generate nutritionally adequate food patterns that meet pre-defined nutrient guidelines. The present LP models were set to satisfy 22 nutrient standards, while minimizing deviation from the mean observed diet of the Seattle Obesity Study (SOS III) sample. Component foods from the Fred Hutch food frequency questionnaire comprised the market basket. LP models generated optimized 2000 kcal food patterns by selecting from all foods, unprocessed foods only, ultra-processed foods only, or some other combination. Optimized patterns created using all foods contained less fat, sugar, and salt, and more vegetables compared to the SOS III mean. Ultra-processed foods were the main sources of added sugar, saturated fat and sodium. Ultra-processed foods also contributed most vitamin E, thiamin, niacin, folate, and calcium, and were the main sources of plant protein. LP models failed to create optimal diets using unprocessed foods only and ultra-processed foods only: no mathematical solution was obtained. Relaxing the vitamin D criterion led to optimized diets based on unprocessed or ultra-processed foods only. However, food patterns created using unprocessed foods were significantly more expensive compared to those created using foods in the ultra-processed category. This work demonstrates that foods from all NOVA categories can contribute to a nutritionally adequate diet.

The Cost of Diets According to Nutritional Quality and Sociodemographic Characteristics: A Population-Based Assessment in Belgium

BACKGROUND

Prices of foods can influence purchase and, therefore, overall quality of diet. However, a limited number of studies have analyzed the cost of diets according to the overall quality of diets taking into account sociodemographic characteristics.

OBJECTIVE

Our aim was to estimate cost variations according to diet quality and to identify sociodemographic characteristics associated with such cost differences in adults' diets in Belgium.

DESIGN

This cross-sectional study used nationally representative data from Belgium.

PARTICIPANTS/SETTINGS

Participants were adults (aged 18 to 64 years; n = 1,158) included in the 2014-2015 Belgian National Food Consumption Survey.

MAIN OUTCOME MEASURES

Dietary assessment was based on two 24-hour dietary recalls and a food frequency questionnaire. The Mediterranean Diet Score and the Healthy Diet Indicator were used to assess diet quality. Daily diet cost was estimated after linking the consumed foods with the 2014 GfK ConsumerScan Panel food price data.

STATISTICAL ANALYSES PERFORMED

Associations were estimated using linear regressions.

RESULTS

The mean daily diet cost was US$6.51 (standard error of mean [SEM] US$0.08; €5.79 [€0.07]). Adjusted for covariates and energy intake, mean (SEM) daily diet cost was significantly higher in the highest tercile (T3) of both diet quality scores than in the T1 (Mediterranean Diet Score: T1 = US$6.29 [US$0.10]; €5.60 [€0.09] vs T3 = US$6.78 [US$0.11]; €6.03 [€0.10]; Healthy Diet Indicator: T1 = US$6.09 [US$0.10]; €5.42 [€0.09] vs T3 = US$7.13 [US$0.11]; €6.34 [€0.10]). Both diet quality and cost were higher in 35- to 64-year-old respondents (vs 18- to 34-year-olds), workers (vs students), and those with higher education levels (vs the lowest). The association between quality and cost of diets was weaker in men and among individuals with higher education levels.

CONCLUSIONS

In Belgium, a high-quality diet was more expensive than a low-quality diet. These findings can be used to inform public health policies.

Food cost and adherence to guidelines for healthy diets: evidence from Belgium

BACKGROUND/OBJECTIVES

Evidence on whether healthy diets are more expensive than less healthy diets is mixed. The relative cost of meeting healthy diet guidelines in Belgium was estimated.

SUBJECTS/METHODS

Data from the nationally representative food consumption survey (FCS) 2014-2015 (n = 3146; 3-64 years) were used. Dietary data were collected through two non-consecutive 24-h recalls (records for children). Average prices for >2000 foods were retrieved from the 2014 GfK ConsumerScan panel and linked with foods consumed in the FCS. Daily costs of meeting nutritional guidelines were estimated across age and household education level groups.

RESULTS

Processed meat contributed most (9.8%-14.4% dependent on age group) to the daily cost of diets. Soft drinks contributed to the daily cost more while fruits and vegetables contributed less for lower versus higher educated households. Compared to individuals not meeting any nutrient recommendations (sodium, saturated fat, free sugar, fibre), the average cost/2000 kcal was significantly higher for individuals meeting one (0.36 ± 0.11€, p = 0.001), two (0.87 ± 0.14€, p < 0.001) or three or more (1.44 ± 0.24€, p < 0.001) recommendations. Similarly, compared to individuals not meeting any of the food-based recommendations (fruit, vegetables, wholegrain, nuts and seeds, red meat, processed meat), the average cost/2000 kcal was significantly higher for individuals meeting three or more (1.04 ± 0.27€; p < 0.001) recommendations. For adults, diets meeting guidelines for vegetables were 20% and for fruits 10% more expensive than diets not meeting those guidelines.

CONCLUSIONS

The cost of diets of Belgian people meeting healthy diet guidelines is greater than of those not meeting guidelines. Policies that make healthy diets more affordable are recommended.

[Quality of diet and daily spending on food by adults with cardiovascular disease in Brazil]

Adherence to a healthy diet depends on factors such as food prices, while studies in developed countries have identified higher costs of more nutritional foods. The current study aimed to assess the direct food expenditures by adults with cardiovascular disease in Brazil, investigating the relationship between cost and quality of diet. The study used data from a randomized clinical trial, the BALANCE Program. The current study is a cross-sectional baseline analysis of participants with high adherence to the trial, conducted in 35 sites in all five major geographic regions of Brazil. Food consumption by 1,160 individuals was collected with a 24-hour dietary recall (24HR), quality of diet was measured with the Diet Quality Index Revised (DQI-R), and direct food costs were estimated from market prices. No significant differences were observed between tertiles of adherence in the direct costs of food or individual characteristics. When all the 24HR were analyzed, there was no correlation between cost and quality of diet (r = 0.38; p = 0.17), while analysis by tertiles showed a weak correlation in the lowest tertile of adherence (r = -0.112; p = 0.03). The study showed absence of differences between direct costs of healthy versus unhealthy foods, a finding that can serve as an incentive for adherence to food recommendations in Brazil, thereby minimizing barriers to the adoption of healthy lifestyles.

Monetary diet cost is positively associated with diet quality and obesity: an analysis of school-aged children in Southwest China

BACKGROUND

Little is known about the relationships between diet cost, dietary intake and obesity in Chinese populations. This study explored how diet cost was related to diet quality and obesity among school-aged children in Southwest China.

METHODS

Data from a cross-sectional study was analysed. Diet cost was estimated based on dietary intake assessed with 24-h dietary recalls and retail food prices. Diet quality was measured using the Chinese Children Dietary Index. Body height, weight, waist circumference and skinfold thicknesses were measured, and their body mass index standard deviation score (BMISDS), waist-to-height ratio (WHtR), fat mass index (FMI) and fat-free mass index (FFMI) were calculated. Multivariate regression models were used to explore the relevance of diet cost to diet quality and obesity.

RESULTS

After adjustment for potential confounders, a positive association was observed between diet quality and energy-adjusted diet cost (β = 0.143, 95% confidence interval, CI: 0.014-0.285, Pfor-trend = 0.0006). Energy-adjusted diet cost also showed a positive association with FMI (β = 0.0354, 95% CI: 0.0001-0.0709, Pfor-trend = 0.01), BMISDS (β = 0.0200, 95% CI: 0.0006-0.0394, Pfor-trend = 0.002) and WHtR (β = 0.0010, 95% CI: 0.0003-0.0017, Pfor-trend = 0.02).

CONCLUSIONS

Energy-adjusted diet cost was independently and positively associated with diet quality and obesity among Chinese school-aged children.

Store patterns of availability and price of food and beverage products across a rural region of Newfoundland and Labrador

OBJECTIVES

Rural populations bear a disproportionate burden of diet-related risk, and one important explanation is retail food access disparities. Much existing literature has focused on subjective measures of the rural retail food environment, as well as urban-rural differences. The purpose of this paper is to examine how objectively measured food availability and prices vary within a rural region, and to explore how store features predict rural food availability and prices.

METHODS

We conducted an observational audit of a census of rural food stores (n = 78) using a modified Nutrition Environment Measures Survey instrument. The study was conducted on the Avalon Peninsula in Newfoundland and Labrador. Observed prices in-store were matched to nutrient composition data and converted to three units of measure for all analyses: unit price ($/kg), serving price ($/serving), and energy price ($/kcal). We examined average availability and prices across the region, and how store features were associated with prices.

RESULTS

Healthy food options were generally less available across the stores than regular items. However, with few exceptions, there were no clear or consistent patterns of difference in availability or pricing between stores of different types. No single product category stood out in terms of a clear price pattern. Store characteristics (including store type, size, ownership, or rurality) did not predict food prices.

CONCLUSIONS

Food availability and prices varied in this rural region, but with limited differences between stores of different types. More research is needed on measuring rural environmental determinants of diet in Canada.

Longitudinal Associations between Monetary Value of the Diet, DASH Diet Score and the Allostatic Load among Middle-Aged Urban Adults

Lower cost can lead to poorer-quality diets, potentially worsening metabolic profiles. We explored these pathways among urban adults. Longitudinal data were extracted from 1224-1479 participants in the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study. DASH(mean) (Dietary Approaches to Stop Hypertension) score was computed using four 24 h recalls (v1/v2: 2004-2013) linked with a national food price database to estimate monetary value of the diet [MVD(mean)]. Allostatic load (AL) was measured at visits 2 (v2) and 3 (v3) in 2009-2018. Mixed-effects regression and structural equation modeling (SEM) were conducted, linking MVD(mean)/DASH(mean) to AL [v2 and annual change(v3-v2)] and exploring mediating pathways between MVD(mean) and AL(v3) through DASH(mean), stratifying by sex, race and poverty status. MVD(mean) tertiles were linearly associated with contemporaneous DASH(mean), after energy adjustment. In mixed-effects regression models, DASH(mean) was consistently linked to lower AL(v2). DASH(mean) and MVD(mean) were positively associated with higher serum albumin(v2). In SEM, MVD(mean) was linked to AL(v3) through DASH(mean), mainly among Whites and specifically for the cholesterol and Waist-Hip-Ratio AL components. In summary, energy and other covariate-adjusted increase in MVD may have a sizeable impact on DASH which can reduce follow-up AL among urban White middle-aged adults. More studies are needed to replicate findings in comparable samples of urban adults.

Global patterns in price elasticities of sugar-sweetened beverage intake and potential effectiveness of tax policy: a cross-sectional study of 164 countries by sex, age and global-income decile

OBJECTIVE

To quantify global relationships between sugar-sweetened beverage (SSB) intake and prices and examine the potential effectiveness of tax policy.

DESIGN

SSB intake data by country, age and sex from the Global Dietary Database were combined with gross domestic product and price data from the World Bank. Intake responsiveness to income and prices was estimated accounting for national income, age and sex differences.

SETTING

164 countries.

POPULATION

Full adult population in each country.

MAIN OUTCOME MEASURES

A consumer demand modelling framework was used to estimate the relationship between SSB intake and prices and derive own-price elasticities (measures of percentage changes in intake from a 1% price change) globally by age and sex. We simulated how a 20% tax would impact SSB intake globally. Tax policy outcomes were examined across countries by global income decile for representative age and sex subgroups.

RESULTS

Own-price responsiveness was highest in lowest income countries, ranging from -0.70 (p<0.100) for women, age 50, to -1.91 (p<0.001) for men, age 80. In the highest income countries, responsiveness was as high as -0.49 (p<0.001) (men, age 20), but was mostly insignificant for older adults. Overall, elasticities were strongest (more negative) at the youngest and oldest age groups, and mostly insignificant for middle-aged adults, particularly in middle-income and high-income countries. Sex differences were mostly negligible. Potential intake reductions from a 20% tax in lowest income countries ranged from 14.5% (95% CI: 29.5%, -0.4%) in women, 35 ≤ age < 60, to 24.9% (44.4%, 5.3%) in men, age ≥60. Intake reductions decreased with country income overall, and were mostly insignificant for middle-aged adults.

CONCLUSIONS

These findings estimate the global price-responsiveness of SSB intake by age and sex, informing ongoing policy discussions on potential effects of taxes.

Dietary cost associated with adherence to the Mediterranean diet, and its variation by socio-economic factors in the UK Fenland Study

High cost of healthy foods could be a barrier to healthy eating. We aimed to examine the association between dietary cost and adherence to the Mediterranean diet in a non-Mediterranean country. We evaluated cross-sectional data from 12 417 adults in the UK Fenland Study. Responses to 130-item FFQ were used to calculate a Mediterranean diet score (MDS). Dietary cost was estimated by matching food consumption data with retail prices of five major supermarkets. Using multivariable-adjusted linear regression, we examined the association of MDS and individual foods with dietary cost in absolute and relative scales. Subsequently, we assessed how much the association was explained by education, income, marital status and occupation, by conducting mediation analysis and testing interaction by these variables. High compared with low MDS (top to bottom third) was associated with marginally higher cost by 5·4 % (95 % CI 4·4, 6·4) or £0·20/d (95 % CI 0·16, 0·25). Participants with high adherence had higher cost associated with the healthier components (e.g. vegetables, fruits and fish), and lower cost associated with the unhealthy components (e.g. red meat, processed meat and sweets) (P for trend<0·001 each). In total, 20·7 % (95 % CI 14·3, 27·0) of the MDS-cost association was explained by the selected socio-economic factors, and the MDS-cost association was of greater magnitude in lower socio-economic groups (P interaction<0·005). Overall, greater adherence to the Mediterranean diet was associated with marginally higher dietary cost, partly modified and explained by socio-economic status, but the potential economic barriers of high adherence might be offset by cost saving from reducing unhealthy food consumption.

Socioeconomic and ethnic differences in the relation between dietary costs and dietary quality: the HELIUS study

BACKGROUND

Healthier dietary patterns are generally more costly than less healthy patterns, but dietary costs may be more important for dietary quality in lower educated and ethnic minority groups. The aim of this study was to investigate the association between dietary costs and dietary quality and interactions with ethnicity and socioeconomic position (SEP).

METHODS

We used cross-sectional data from 4717 Dutch, Surinamese, Turkish and Moroccan origin participants of the multi-ethnic HELIUS study (the Netherlands), who completed an ethnic-specific food frequency questionnaire (FFQ). The primary outcome measure was dietary quality according to adherence to the Dutch Healthy Diet index 2015 (DHD15-index, range 0-130). Individual dietary costs (the monetary value attached to consumed diets in Euros) were estimated by merging a food price variable with the FFQ nutrient composition database. Regression analyses were used to examine main and interaction effects. Analyses were adjusted for age, sex, smoking, energy intake, physical activity, ethnicity and educational level.

RESULTS

Having higher dietary costs was associated with higher dietary quality. Analyses stratified by educational level showed that associations were stronger in higher educated (Btertile3 = 8.06, 95%CI = 5.63; 10.48) than in lower educated participants (Btertile3 = 5.09, 95%CI = 2.74; 7.44). Stratification by ethnic origin showed strongest associations in Turkish participants (Btertile2 = 9.31, 95%CI = 5.96; 12.65) and weakest associations in Moroccan participants (Btertile3 = 4.29, 95%CI = 0.58; 8.01). Regardless of their level of education, Turkish and Moroccan individuals consumed higher quality diets at the lowest cost than Dutch participants.

CONCLUSIONS

The importance of dietary costs for dietary quality differs between socioeconomic and ethnic subgroups. Increasing individual food budgets or decreasing food prices may be effective for the promotion of healthy diets, but differential effects across socioeconomic and ethnic subgroups may be expected.

Do food expenditure patterns of Supplemental Nutrition Assistance Program households meet Thrifty Food Plan recommendations?

The Supplemental Nutrition Assistance Program (SNAP) increases the food purchasing power of its clients by distribution of monthly benefits. The goal of this study was to determine if food expenditure patterns of SNAP households meet the Thrifty Food Plan (TFP) recommendations. Results indicated that greater TFP-adjusted total grocery expenditure was significantly associated with greater spending on low fat dairy, vegetables, whole grains and fruits relative to the recommendations. Future research could focus on psychosocial factors associated with inadequate grocery spending among SNAP households.

Longitudinal change in the diet's monetary value is associated with its change in quality and micronutrient adequacy among urban adults

Background

Reducing diet costs may lead to the selection of energy-dense foods, such as refined grains or foods high in added sugars and/or fats, which can lower overall dietary quality. We examined the longitudinal association between the monetary value of the diet (MVD) and the overall dietary quality across sex, race and income groups.

Methods and findings

Longitudinal data from 1,466 adult urban participants from Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study were used. Healthy Eating Index–2010 (HEI–2010) and Mean Adequacy Ratio (MAR) were computed and a national food price database was used to estimate MVD. Multiple linear regression analyses were conducted linking annual rates of change (Δ) in MVD to ΔHEI-2010 and ΔMAR, stratifying by sex, race and income groups. Among key findings, ΔHEI-2010 was comparable across socio-demographic groups, while ΔMAR was higher among women and individuals above poverty. Adjusting for key covariates, ΔMVD was positively associated with both ΔHEI-2010 and ΔMAR, and with a consistently stronger association among individuals above poverty, specifically for the total proteins and empty calories components of HEI-2010 and several nutrient adequacy ratios (NARs: vitamins C, E, B-6 and Zinc). ΔMVD-ΔMAR association was stronger in women, mainly influenced by ΔMVD’s positive associations with B-vitamins, copper, calcium, magnesium and phosphorus NARs. ΔMVD-Δvitamin D NAR’s positive relationship was stronger among Whites, while ΔMVD-Δvitamin B-12 NAR’s association was stronger among African-Americans.

Conclusions

In sum, a potential increase in MVD may have a stronger impact on dietary quality among urban adult women and above-poverty individuals.

Meeting UK dietary recommendations is associated with higher estimated consumer food costs: an analysis using the National Diet and Nutrition Survey and consumer expenditure data, 2008-2012

OBJECTIVE

To test whether diets achieving recommendations from the UK's Scientific Advisory Committee on Nutrition (SACN) were associated with higher monetary costs in a nationally representative sample of UK adults.

DESIGN

A cross-sectional study linking 4 d diet diaries in the National Diet and Nutrition Survey (NDNS) to contemporaneous food price data from a market research firm. The monetary cost of diets was assessed in relation to whether or not they met eight food- and nutrient-based recommendations from SACN. Regression models adjusted for potential confounding factors. The primary outcome measure was individual dietary cost per day and per 2000 kcal (8368 kJ).

SETTING

UK.

SUBJECTS

Adults (n 2045) sampled between 2008 and 2012 in the NDNS.

RESULTS

On an isoenergetic basis, diets that met the recommendations for fruit and vegetables, oily fish, non-milk extrinsic sugars, fat, saturated fat and salt were estimated to be between 3 and 17 % more expensive. Diets meeting the recommendation for red and processed meats were 4 % less expensive, while meeting the recommendation for fibre was cost-neutral. Meeting multiple targets was also associated with higher costs; on average, diets meeting six or more SACN recommendations were estimated to be 29 % more costly than isoenergetic diets that met no recommendations.

CONCLUSIONS

Food costs may be a population-level barrier limiting the adoption of dietary recommendations in the UK. Future research should focus on identifying systems- and individual-level strategies to enable consumers achieve dietary recommendations without increasing food costs. Such strategies may improve the uptake of healthy eating in the population.

Higher Dietary Cost Is Associated with Higher Diet Quality: A Cross-Sectional Study among Selected Malaysian Adults

Food price is a determining factor of food choices; however its relationship with diet quality is unclear in Malaysia. This study aimed to examine socio-economic characteristics and daily dietary cost (DDC) in relation to diet quality in the state of Selangor, Malaysia. Dietary intake was assessed using a Food Frequency Questionnaire (FFQ) and diet quality was estimated using a Malaysian Healthy Eating Index (M-HEI). DDC in Malaysian Ringgit (RM) was calculated from dietary intake and national food prices. Linear regression models were fitted to determine associations between DDC and M-HEI scores and predictors of diet quality. The mean M-HEI score of respondents was 61.31 ± 10.88 and energy adjusted DDC was RM10.71/2000 kcal (USD 2.49). The highest quintile of adjusted DDC had higher M-HEI scores for all respondents (Q1: 57.14 ± 10.07 versus Q5: 63.26 ± 11.54, p = 0.001). There were also positive associations between DDC and M-HEI scores for fruits (p < 0.001) and vegetables (p = 0.017) for all respondents. Predictors of diet quality included carbohydrate (β = 0290; p < 0.001) and fat intakes (β = −0.242; p < 0.001) and energy adjusted DDC (β= 0.196; p < 0.001). Higher dietary cost is associated with healthy eating among Malaysian adults.

Accessibility and Affordability of Supermarkets: Associations With the DASH Diet

INTRODUCTION

It is unknown whether there is an interplay of affordability (economic accessibility) and proximity (geographic accessibility) of supermarkets in relation to having a Dietary Approaches to Stop Hypertension (DASH)-accordant diet.

METHODS

Data (collected: 2005-2015, analyzed: 2016) were from the cross-sectional, population-based Fenland Study cohort: 9,274 adults aged 29-64 years, living in Cambridgeshire, United Kingdom. Dietary quality was evaluated using an index of DASH dietary accordance, based on recorded consumption of foods and beverages in a validated 130-item, semi-quantitative food frequency questionnaire. DASH accordance was defined as a DASH score in the top quintile. Dietary costs (£/day) were estimated by attributing a food price variable to the foods consumed according to the questionnaire. Individuals were classified as having low-, medium-, or high-cost diets. Supermarket affordability was determined based on the cost of a 101-item market basket. Distances between home address to the nearest supermarket (geographic accessibility) and nearest economically-appropriate supermarket (economic accessibility) were divided into tertiles.

RESULTS

Higher-cost diets were more likely to be DASH-accordant. After adjustment for key demographics and exposure to other food outlets, individuals with lowest economic accessibility to supermarkets had lower odds of being DASH-accordant (OR=0.59, 95% CI=0.52, 0.68) than individuals with greatest economic accessibility. This association was stronger than with geographic accessibility alone (OR=0.85, 95% CI=0.74, 0.98).

CONCLUSIONS

Results suggest that geographic and economic access to food should be taken into account when considering approaches to promote adherence to healthy diets for the prevention of cardiovascular diseases and other chronic disease.

The Challenge in Improving the Diets of Supplemental Nutrition Assistance Program Recipients: A Historical Commentary

This paper provides a historical background for the current nutrition issues faced by the Supplemental Nutrition Assistance Program (SNAP). The Food Stamp Program evolved into SNAP during a period when U.S. diets, particularly those of the poor, became less healthful. During the 1960s, the U.S. (Kennedy-Johnson era) addressed malnutrition first with a pilot project focused on retail sales and cash food stamps, which showed that low-income consumers purchased relatively healthy foods for a fairly high-quality diet. Southern politicians in the House of Representatives wanted a program similar to an earlier subsidized commodity distribution program. The pilot provided the evidence northern urban politicians sought, and they held the farm bill hostage until southern rural interests agreed to an unfettered Food Stamp Program that allowed purchases directly from retailers. A final Food Stamp Program law was incorporated into the farm bill and passed. This program shifted in 1977 to a full cash benefit system later, first using food stamps to act as cash and later an Electronic Benefit Transfer program. The program was designed at a time of a very healthful diet of lower-SES Americans. As diets of lower-income Americans changed and the entire food system shifted, the program has not been adjusted in any manner. Today, 50%-66% of the calories in the American diet, particularly that of low-SES Americans, come from highly processed foods containing excessive refined carbohydrates, sodium, unhealthy saturated fats, and added sugar. The SNAP design has not responded to these shifts in diet and the powerful interests controlling our food system. This twist in the U.S. diet and food system presents a major dilemma to those attempting to form a healthy food program based on the results of an effective pilot project.

Dietary Diversity, Diet Cost, and Incidence of Type 2 Diabetes in the United Kingdom: A Prospective Cohort Study

BACKGROUND

Diet is a key modifiable risk factor for multiple chronic conditions, including type 2 diabetes (T2D). Consuming a range of foods from the five major food groups is advocated as critical to healthy eating, but the association of diversity across major food groups with T2D is not clear and the relationship of within-food-group diversity is unknown. In addition, there is a growing price gap between more and less healthy foods, which may limit the uptake of varied diets. The current study had two aims: first, to examine the association of reported diversity of intake of food groups as well as their subtypes with risk of developing T2D, and second, to estimate the monetary cost associated with dietary diversity.

METHODS AND FINDINGS

A prospective study of 23,238 participants in the population-based EPIC-Norfolk cohort completed a baseline Food Frequency Questionnaire in 1993-1997 and were followed up for a median of 10 y. We derived a total diet diversity score and additional scores for diversity within each food group (dairy products, fruits, vegetables, meat and alternatives, and grains). We used multivariable Cox regression analyses for incident diabetes (892 new cases), and multivariable linear regression for diet cost. Greater total diet diversity was associated with 30% lower risk of developing T2D (Hazard ratio [HR] 0.70 [95% CI 0.51 to 0.95]) comparing diets comprising all five food groups to those with three or fewer, adjusting for confounders including obesity and socioeconomic status. In analyses of diversity within each food group, greater diversity in dairy products (HR 0.61 [0.45 to 0.81]), fruits (HR 0.69 [0.52 to 0.90]), and vegetables (HR 0.67 [0.52 to 0.87]) were each associated with lower incident diabetes. The cost of consuming a diet covering all 5 food groups was 18% higher (£4.15/day [4.14 to 4.16]) than one comprising three or fewer groups. Key limitations are the self-reported dietary data and the binary scoring approach whereby some food groups contained both healthy and less healthy food items.

CONCLUSIONS

A diet characterized by regular consumption of all five food groups and by greater variety of dairy, fruit, and vegetable subtypes, appears important for a reduced risk of diabetes. However, such a diet is more expensive. Public health efforts to prevent diabetes should include food price policies to promote healthier, more varied diets.

Socioeconomic inequalities in the healthiness of food choices: Exploring the contributions of food expenditures

Investigations of the contribution of food costs to socioeconomic inequalities in diet quality may have been limited by the use of estimated (vs. actual) food expenditures, not accounting for where individuals shop, and possible reverse mediation between food expenditures and healthiness of food choices. This study aimed to explore the extent to which food expenditure mediates socioeconomic inequalities in the healthiness of household food choices. Observational panel data on take-home food and beverage purchases, including expenditure, throughout 2010 were obtained for 24,879 UK households stratified by occupational social class. Purchases of (1) fruit and vegetables and (2) less-healthy foods/beverages indicated healthiness of choices. Supermarket choice was determined by whether households ever visited market-defined high-price and/or low-price supermarkets. Results showed that higher occupational social class was significantly associated with greater food expenditure, which was in turn associated with healthier purchasing. In mediation analyses, 63% of the socioeconomic differences in choices of less-healthy foods/beverages were mediated by expenditure, and 36% for fruit and vegetables, but these figures were reduced to 53% and 31% respectively when controlling for supermarket choice. However, reverse mediation analyses were also significant, suggesting that 10% of socioeconomic inequalities in expenditure were mediated by healthiness of choices. Findings suggest that lower food expenditure is likely to be a key contributor to less-healthy food choices among lower socioeconomic groups. However, the potential influence of cost may have been overestimated previously if studies did not account for supermarket choice or explore possible reverse mediation between expenditure and healthiness of choices.

Diet inequality prevails among consumers interested and knowledgeable in nutrition

Background

Previous studies have demonstrated a correlation between diet cost and adherence to nutritional recommendations among consumers in general. This has adverse effects on diet and health inequality. It could be hypothesized that consumers knowledgeable in nutrition escape this correlation.

Objective

Investigate whether the previously observed relationship between diet cost and nutritional quality prevails among consumers with an above-average interest in and knowledge of nutrition.

Design

Full open diet registrations of 330 students taking a basic university-level course in nutrition over a total of 780 days.

Results

The consumers with the highest daily average diet cost differ from the lowest cost quartile: The diets had higher micronutrient density, more fruits and vegetables, and lower energy density. The highest cost daily diet quartile had a significantly higher energy adjusted intake of the micronutrients that were on average consumed below the recommendation (vitamin D, folate, and iron for women). On the other hand, alcohol intake was significantly higher among the high diet cost group. The highest diet cost respondents consumed more fish, meat, coffee, and spreads, whereas the lowest diet cost respondents had a higher consumption of cereals, bread, jam, sausage, and milk.

Conclusions

Dietary differences prevail even in the above-average interested and knowledgeable group. The respondents did not use their higher level of knowledge to break this commonly observed relationship. This suggests that an increased minimum level of knowledge in nutrition may not by itself eliminate dietary inequality.

Monetary Value of Diet Is Associated with Dietary Quality and Nutrient Adequacy among Urban Adults, Differentially by Sex, Race and Poverty Status

OBJECTIVE

The association between monetary value of the diet (MVD, $/day) with dietary quality was examined using a large sample of urban US adults, differentially by socio-demographic factors.

METHODS

This was a cross-sectional study of 2,111 participants, aged 30-64y, using data from the Healthy Aging in Neighborhoods of Diversity across the Life Span Study. Dietary quality indices included Healthy Eating Index-2010 (HEI-2010) and Mean Adequacy Ratio (MAR), (two 24-hr recalls). A national food price database was used to estimate MVD. Multiple linear/logistic regression analyses were conducted stratifying separately by sex, race and poverty status.

RESULTS

Women had significantly higher HEI-2010 scores than men (43.35 vs 41.57 out of 100, respectively), whereas MAR scores were higher for men (76.8 vs 69.9, out of 100), reflecting energy intake gender differentials. Importantly, a $3/day higher MVD (IQR: $3.70/d (Q1) to $6.62/d (Q4)) was associated with a 4.98±0.35 higher total HEI-2010 and a 3.88±0.37 higher MAR score, after energy-adjustment and control for key confounders. For HEI-2010 and MAR, stronger associations were observed among participants above poverty and among women, whilethe MVD vs. HEI-2010 association was additionally stronger among Whites. Sex and poverty status differentials were observed for many MAR and some HEI-2010 components.

CONCLUSIONS

Despite positive associations between measures of dietary quality and MVD, particularly above poverty and among women, approaching compliance with the Dietary Guidelines (80 or more for HEI-2010) requires a substantially higher MVD. Thus, nutrition education may further improve people's decision-making regarding food venues and dietary choices.

Validating self-reported food expenditures against food store and eating-out receipts

Objectives

To compare objective food store and eating-out receipts with self-reported household food expenditures.

Design and setting

The Seattle Obesity Study (SOS II) was based on a representative sample of King County adults, Washington, USA. Self-reported household food expenditures were modeled on the Flexible Consumer Behavior Survey (FCBS) Module from 2007–2009 National Health and Nutrition Examination Survey (NHANES). Objective food expenditure data were collected using receipts. Self-reported food expenditures for 447 participants were compared to receipts using paired t-tests, Bland-Altman plots, and kappa statistics. Bias by socio-demographics was also examined.

Results

Self-reported expenditures closely matched with objective receipt data. Paired t-tests showed no significant differences between receipts and self-reported data on total food expenditures, expenditures at food stores, or eating out. However, the highest income strata showed weaker agreement. Bland Altman plots confirmed no significant bias across both methods - mean difference: 6.4; agreement limits: −123.5, 143.4 for total food expenditures, mean difference 5.7 for food stores, and mean difference 1.7 for eating-out. Kappa statistics showed good agreement for each (kappa 0.51, 0.41 and 0.49 respectively. Households with higher education and income had significantly more number of receipts and higher food expenditures.

Conclusion

Self-reported food expenditures using NHANES questions, both for food stores and eating-out, serve as a decent proxy for objective household food expenditures from receipts. This method should be used with caution among high income populations, or with high food expenditures. This is the first validation of the FCBS food expenditures question using food store and eating-out receipts.

Does the importance of dietary costs for fruit and vegetable intake vary by socioeconomic position?

Evidence suggests that diets meeting recommendations for fruit and vegetable (F&V) intake are more costly. Dietary costs may be a greater constraint on the diet quality of people of lower socioeconomic position (SEP). The aim of this study was to examine whether dietary costs are more strongly associated with F&V intake in lower-SEP groups than in higher-SEP groups. Data on individual participants’ education and income were available from a population-based, cross-sectional study of 10 020 British adults. F&V intake and dietary costs (GBP/d) were derived from a semi-quantitative FFQ. Dietary cost estimates were based on UK food prices. General linear models were used to assess associations between SEP, quartiles of dietary costs and F&V intake. Effect modification of SEP gradients by dietary costs was examined with interaction terms. Analysis demonstrated that individuals with lowest quartile dietary costs, low income and low education consumed less F&V than individuals with higher dietary costs, high income and high education. Significant interaction between SEP and dietary costs indicated that the association between dietary costs and F&V intake was stronger for less-educated and lower-income groups. That is, socioeconomic differences in F&V intake were magnified among individuals who consumed lowest-cost diets. Such amplification of socioeconomic inequalities in diet among those consuming low-cost diets indicates the need to address food costs in strategies to promote healthy diets. In addition, the absence of socioeconomic inequalities for individuals with high dietary costs suggests that high dietary costs can compensate for lack of other material, or psychosocial resources.

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

CONTEXT

It is well established in the literature that healthier diets cost more than unhealthy diets.

OBJECTIVE

The aim of this review was to examine the contribution of food prices and diet cost to socioeconomic inequalities in diet quality.

DATA SOURCES

A systematic literature search of the PubMed, Google Scholar, and Web of Science databases was performed.

STUDY SELECTION

Publications linking food prices, dietary quality, and socioeconomic status were selected.

DATA EXTRACTION

Where possible, review conclusions were illustrated using a French national database of commonly consumed foods and their mean retail prices.

DATA SYNTHESIS

Foods of lower nutritional value and lower-quality diets generally cost less per calorie and tended to be selected by groups of lower socioeconomic status. A number of nutrient-dense foods were available at low cost but were not always palatable or culturally acceptable to the low-income consumer. Acceptable healthier diets were uniformly associated with higher costs. Food budgets in poverty were insufficient to ensure optimum diets.

CONCLUSIONS

Socioeconomic disparities in diet quality may be explained by the higher cost of healthy diets. Identifying food patterns that are nutrient rich, affordable, and appealing should be a priority to fight social inequalities in nutrition and health.

The food retail revolution in China and its association with diet and health

The processed food sector in low- and middle-income countries has grown rapidly. Little is understood about its effect on obesity. Using data from 14,976 participants aged two and older in the 2011 China Health and Nutrition Survey, this paper examines patterns of processed food consumption and their impacts on obesity while considering the endogeneity of those who purchase processed foods. A major assumption of our analysis of the impact of processed foods on overweight and obesity was that the consumption of processed foods is endogenous due to their accessibility and urbanicity levels. The results show that 74.5% of participants consumed processed foods, excluding edible oils and other condiments; 28.5% of participants' total daily energy intake (EI) was from processed foods. Children and teenagers in megacities had the highest proportion of EI (40.2%) from processed foods. People who lived in megacities or highly urbanized neighborhoods with higher incomes and educational achievement consumed more processed foods. When controlling for endogeneity, only the body mass index (BMI) and risk of being overweight of children ages two to eighteen are adversely associated with processed foods (+4.97 BMI units, 95% confidence interval (CI): 1.66-8.28; odds ratio (OR) = 3.63, 95% CI: 1.45-9.13). Processed food purchases represent less than a third of current Chinese food purchases. However, processed food purchases are growing at the rate of 50% per year, and we must begin to understand the implications for the future.

Higher nutritional quality at no additional cost among low-income households: insights from food purchases of "positive deviants"

BACKGROUND

It is unknown whether diet quality is correlated with actual food expenditure. According to the positive deviance theory, the study of actual food expenditure by people with limited economic resources could help identify beneficial food-purchasing behavior.

OBJECTIVES

The aims were to investigate the relation between actual expenditure on food and nutritional quality and to identify "positive deviants" among low-income households.

DESIGN

Individuals in deprived social situations (n = 91) were recruited as part of the "Opticourses" nutrition intervention conducted in 2012-2014 in poor districts of Marseille, France. Opticourses participants collected food-purchase receipts for their household over a 1-mo period. "Actual diet costs" and "estimated diet costs" were calculated per 2000 kcal of food purchases by using actual expenditures and a standard food price database of food consumed by a representative sample of French adults, respectively. Mean adequacy ratio (MAR), mean excess ratio (MER), and energy density (ED) were used as nutritional quality indicators. "Positive deviants" were defined as having a higher MAR and a lower MER than the respective median values.

RESULTS

Opticourses participants selected less-expensive food options than the average French population, both within a food group and for a given food item. Higher diet costs were associated with higher nutritional quality (higher MAR, lower ED), regardless of whether costs were calculated from actual expenditure or on the basis of standard food prices. Twenty-one positive deviants were identified. They made significantly healthier purchases than did other participants (MAR: +13%; MER: -90%. ED: -22%) at higher estimated diet costs. Yet, they did not spend more on food (having the same actual diet costs), which showed that they purchased food with a higher nutritional quality for their price.

CONCLUSION

In this low-income population, actual diet cost was positively correlated with nutritional quality, yet the results showed that higher diet quality is not necessarily more costly when foods with higher nutritional quality for their price are selected. The Opticourses intervention was registered at clinicaltrials.gov as NCT02383875.

Greater accordance with the Dietary Approaches to Stop Hypertension dietary pattern is associated with lower diet-related greenhouse gas production but higher dietary costs in the United Kingdom

BACKGROUND

The Dietary Approaches to Stop Hypertension (DASH) diet is a proven way to prevent and control hypertension and other chronic disease. Because the DASH diet emphasizes plant-based foods, including vegetables and grains, adhering to this diet might also bring about environmental benefits, including lower associated production of greenhouse gases (GHGs).

OBJECTIVE

The objective was to examine the interrelation between dietary accordance with the DASH diet and associated GHGs. A secondary aim was to examine the retail cost of diets by level of DASH accordance.

DESIGN

In this cross-sectional study of adults aged 39-79 y from the European Prospective Investigation into Cancer and Nutrition-Norfolk, United Kingdom cohort (n = 24,293), dietary intakes estimated from food-frequency questionnaires were analyzed for their accordance with the 8 DASH food and nutrient-based targets. Associations between DASH accordance, GHGs, and dietary costs were evaluated in regression analyses. Dietary GHGs were estimated with United Kingdom-specific data on carbon dioxide equivalents associated with commodities and foods. Dietary costs were estimated by using national food prices from a United Kingdom-based supermarket comparison website.

RESULTS

Greater accordance with the DASH dietary targets was associated with lower GHGs. Diets in the highest quintile of accordance had a GHG impact of 5.60 compared with 6.71 kg carbon dioxide equivalents/d for least-accordant diets (P < 0.0001). Among the DASH food groups, GHGs were most strongly and positively associated with meat consumption and negatively with whole-grain consumption. In addition, higher accordance with the DASH diet was associated with higher dietary costs, with the mean cost of diets in the top quintile of DASH scores 18% higher than that of diets in the lowest quintile (P < 0.0001).

CONCLUSIONS

Promoting wider uptake of the DASH diet in the United Kingdom may improve population health and reduce diet-related GHGs. However, to make the DASH diet more accessible, food affordability, particularly for lower income groups, will have to be addressed.

The relation of potassium and sodium intakes to diet cost among U.S. adults

The 2010 Dietary Guidelines recommended that Americans increase potassium and decrease sodium intakes to reduce the burden of hypertension. One reason why so few Americans meet the recommended potassium or sodium goals may be perceived or actual food costs. This study explored the monetary costs associated with potassium and sodium intakes using national food prices and a representative sample of US adults. Dietary intake data from the 2001-2002 National Health and Nutrition Examination Survey were merged with a national food prices database. In a population of 4744 adults, the association between the energy-adjusted sodium and potassium intakes, and the sodium-to-potassium ratio (Na:K) and energy-adjusted diet cost was evaluated. Diets that were more potassium-rich or had lower Na:K ratios were associated with higher diet costs, while sodium intakes were not related to cost. The difference in diet cost between extreme quintiles of potassium intakes was $1.49 (95% confidence interval: 1.29, 1.69). A food-level analysis showed that beans, potatoes, coffee, milk, bananas, citrus juices and carrots are frequently consumed and low-cost sources of potassium. Based on existing dietary data and current American eating habits, a potassium-dense diet was associated with higher diet costs, while sodium was not. Price interventions may be an effective approach to improve potassium intakes and reduce the Na:K ratio of the diet. The present methods helped identify some alternative low-cost foods that were effective in increasing potassium intakes. The identification and promotion of lower-cost foods to help individuals meet targeted dietary recommendations could accompany future dietary guidelines.

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

BACKGROUND/OBJECTIVES

Diet cost could influence dietary patterns, with potential health consequences. Assigning a monetary cost to diet is challenging, and there are contrasting methods in the literature. This study compares two methods-a food cost database linked to 4-day diet diaries and an individual cost calculated from household till receipts.

SUBJECTS/METHODS

The Diet and Nutrition Tool for Evaluation (DANTE) had supermarket prices (cost per 100 g) added to its food composition table. Agreement between diet costs calculated using DANTE from food diaries and expenditure recorded using food purchase till receipts for 325 individuals was assessed using correlation and Bland Altman (BA) plots.

RESULTS

The mean difference between the methods' estimates was £0.10. The BA showed 95% limits of agreement of £2.88 and -£3.08. Excluding the highest 5% of diet cost values from each collection method reduced the mean difference to £0.02, with limits of agreement ranging from £2.31 to -£2.35. Agreement between the methods was stronger for males and for adults.

CONCLUSIONS

Diet cost estimates using a food price database with 4-day food diaries are comparable to recorded expenditure from household till receipts at the population or group level. At the individual level, however, estimates differed by as much as £3.00 per day. The methods agreed less when estimating diet costs of children, females or those with more expensive diets.