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.

The Relative Costs of High- vs. Low-Energy-Density Foods and More vs. Less Healthful Beverages Consumed by Children

OBJECTIVE

To compare grocery costs between relatively high energy density foods and sugar-sweetened/high-fat beverages and lower energy density foods and more healthful beverages in children's diets.

METHODS

Sixty foods were divided into high and low energy density baskets. Fourteen beverages were designated to either basket based on fat and added-sugar content. Prices were collected at 60 grocery stores and composite costs compared between baskets using Wilcoxon tests.

RESULTS

The cost per kilogram of high energy density foods was greater, but the cost per quart of sugar-sweetened/high-fat beverages was lower than more healthful beverages. The cost per 1000 calories and the cost per serving of the high energy density basket were lower.

CONCLUSIONS

The relative cost of high and low energy density foods in children's diets depends on how cost is quantified. "Pound-for-pound," lower energy density foods and more healthful beverages are generally less expensive, but high energy density foods and less healthful beverages are cheaper per serving. Cost metrics including other factors (e.g. time cost) may further clarify the role of grocery prices in children's diets.

Beyond the sticker price: including and excluding time in comparing food prices

BACKGROUND

An ongoing debate in the literature is how to measure the price of food. Most analyses have not considered the value of time in measuring the price of food. Whether or not the value of time is included in measuring the price of a food may have important implications for classifying foods based on their relative cost.

OBJECTIVE

The purpose of this article is to compare prices that exclude time (time-exclusive price) with prices that include time (time-inclusive price) for 2 types of home foods: home foods using basic ingredients (home recipes) vs. home foods using more processed ingredients (processed recipes). The time-inclusive and time-exclusive prices are compared to determine whether the time-exclusive prices in isolation may mislead in drawing inferences regarding the relative prices of foods.

DESIGN

We calculated the time-exclusive price and time-inclusive price of 100 home recipes and 143 processed recipes and then categorized them into 5 standard food groups: grains, proteins, vegetables, fruit, and dairy. We then examined the relation between the time-exclusive prices and the time-inclusive prices and dietary recommendations.

RESULTS

For any food group, the processed food time-inclusive price was always less than the home recipe time-inclusive price, even if the processed food's time-exclusive price was more expensive. Time-inclusive prices for home recipes were especially higher for the more time-intensive food groups, such as grains, vegetables, and fruit, which are generally underconsumed relative to the guidelines.

CONCLUSION

Focusing only on the sticker price of a food and ignoring the time cost may lead to different conclusions about relative prices and policy recommendations than when the time cost is included.

The inverse relationship between food price and energy density: is it spurious?

Objective

An important debate in the literature is whether or not higher energy-dense foods are cheaper than less energy-dense foods. The present communication develops and applies an easy statistical test to determine if the relationship between food price and energy density is an artifact of how the data units are constructed (i.e. is it ‘spurious’ or ‘real’?).

Design

After matching data on 4430 different foods from the National Health and Nutrition Examination Survey with corresponding prices from the Center for Nutrition Policy and Promotion’s Food Prices Database, we use a simple regression model to test if the relationship between food price and energy density is ‘real’ or ‘spurious’.

Setting

USA.

Subjects

Total sample size is 4430 observations of consumed foods from 4578 participants from the non-institutionalized US adult population (aged 19 years and over).

Results

Over all 4430 foods, the null hypothesis of a spurious inverse relationship between food price per energy density and energy density is not rejected. When the analysis is broken down by twenty-five food groups, there are only two cases where the inverse relationship is not spurious. In fact, the majority of non-spurious relationships between food price and energy density are positive, not negative.

Conclusions

One of the main arguments put forth regarding the poor diet quality of low-income households is that high energy-dense food is cheaper than lower energy-dense food. We find almost no statistical support for higher energy-dense food being cheaper than low energy-dense food. While economics certainly plays a role in explaining low nutritional quality, more sophisticated economic arguments are required and discussed.