High monetary costs of dietary patterns associated with lower body mass index: a population-based study

New metrics of affordable nutrition: which vegetables provide most nutrients for least cost?

Measuring food prices per gram, rather than per calorie, is one way to make healthful vegetables appear less expensive. However, a better measure of affordability would take the nutrient content of vegetables into account. This study, based on analyses of US Department of Agriculture datasets, aimed to identify which vegetables, including juices and soups, provided the most nutrients per unit cost. Nutrient density was measured using the Nutrient Rich Foods (NRF) index, based on nine nutrients to encourage: protein; fiber; vitamins A, C, and E; calcium; iron; magnesium; and potassium; and on three nutrients to limit: saturated fat, added sugar, and sodium. Food cost in dollars was calculated per 100 g, per 100 kcal, per serving, and per nutrient content. One-way analyses of variance with post hoc tests were used to determine statistical significance. Results showed that tomato juices and tomato soups, dark green leafy and nonleafy vegetables, and deep yellow vegetables, including sweet potatoes, had the highest NRF scores overall. Highest NRF scores per dollar were obtained for sweet potatoes, white potatoes, tomato juices and tomato soups, carrots, and broccoli. Tomato sauces, raw tomatoes, and potato chips were eaten more frequently than were many other vegetables that were both more affordable and more nutrient-rich. These new measures of affordable nutrition can help foodservice and health professionals identify those vegetables that provide the highest nutrient density per unit cost. Processed vegetables, including soups and juices, can contribute to the quality and the affordability of the diet.

Differences in dietary intakes, food sources and determinants of total flavonoids between Mediterranean and non-Mediterranean countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study

A greater adherence to the traditional Mediterranean (MED) diet is associated with a reduced risk of developing chronic diseases. This dietary pattern is based on higher consumption of plant products that are rich in flavonoids. We compared the total flavonoid dietary intakes, their food sources and various lifestyle factors between MED and non-MED countries participating in the EPIC study. Flavonoid intakes and their food sources for 35,628 subjects, aged 35-74 years and recruited between 1992 and 2000, in twenty-six study centres were estimated using standardised 24 h dietary recall software (EPIC-Soft®). An ad hoc food composition database on flavonoids was compiled using analytical data from the United States Department of Agriculture and Phenol-Explorer databases. Moreover, it was expanded to include using recipes, estimations of missing values and flavonoid retention factors. No significant differences in total flavonoid mean intake between non-MED countries (373·7 mg/d) and MED countries (370·2 mg/d) were observed. In the non-MED region, the main contributors were proanthocyanidins (48·2%) and flavan-3-ol monomers (24·9%) and the principal food sources were tea (25·7%) and fruits (32·8%). In the MED region, proanthocyanidins (59·0%) were by far the most abundant contributor and fruits (55·1%), wines (16·7%) and tea (6·8%) were the main food sources. The present study shows similar results for total dietary flavonoid intakes, but significant differences in flavonoid class intakes, food sources and some characteristics between MED and non-MED countries. These differences should be considered in studies about the relationships between flavonoid intake and chronic diseases.

Nutrient intakes linked to better health outcomes are associated with higher diet costs in the US

PURPOSE

Degrees of nutrient intake and food groups have been linked to differential chronic disease risk. However, intakes of specific nutrients may also be associated with differential diet costs and unobserved differences in socioeconomic status (SES). The present study examined degrees of nutrient intake, for every key nutrient in the diet, in relation to diet cost and SES.

METHODS

Socio-demographic data for a stratified random sample of adult respondents in the Seattle Obesity Study were obtained through telephone survey. Dietary intakes were assessed using food frequency questionnaire (FFQ) (n = 1,266). Following standard procedures, nutrient intakes were energy-adjusted using the residual method and converted into quintiles. Diet cost for each respondent was estimated using Seattle supermarket retail prices for 384 FFQ component foods.

RESULTS

Higher intakes of dietary fiber, vitamins A, C, D, E, and B12, beta carotene, folate, iron, calcium, potassium, and magnesium were associated with higher diet costs. The cost gradient was most pronounced for vitamin C, beta carotene, potassium, and magnesium. Higher intakes of saturated fats, trans fats and added sugars were associated with lower diet costs. Lower cost lower quality diets were more likely to be consumed by lower SES.

CONCLUSION

Nutrients commonly associated with a lower risk of chronic disease were associated with higher diet costs. By contrast, nutrients associated with higher disease risk were associated with lower diet costs. The cost variable may help somewhat explain why lower income groups fail to comply with dietary guidelines and have highest rates of diet related chronic disease.

Low social interactions in eating disorder patients in childhood and adulthood: A multi-centre European case control study

The objective of this article was to examine lifestyle behaviours in eating disorder (ED) patients and healthy controls. A total of 801 ED patients and 727 healthy controls from five European countries completed the questions related to lifestyle behaviours of the Cross-Cultural Questionnaire (CCQ). For children, the ED sample exhibited more solitary activities (rigorously doing homework [p<0.001] and watching TV [p<0.05] and less socializing with friends [p<0.05]) than the healthy control group and this continued in adulthood. There were minimal differences across ED sub-diagnoses and various cross-cultural differences emerged. Reduced social activities may be an important risk and maintaining factor for ED symptomatology.

Low income is associated with poor adherence to a Mediterranean diet and a higher prevalence of obesity: cross-sectional results from the Moli-sani study

OBJECTIVES

To examine cross-sectional associations of socioeconomic status (ie, income and education) with an adherence to a Mediterranean dietary pattern and obesity prevalence.

DESIGN

Cross-sectional study on a sample of Italian subjects enrolled in the Moli-sani Project, a population-based cohort study. The Italian EPIC food frequency questionnaire was used to determine food intake. Adherence to a Mediterranean diet (MD) was appraised according to both the Mediterranean score elaborated by Trichopoulou (MDS) and the novel Italian Mediterranean Index (IMI) and to the a posteriori scores derived from principal component analysis. Four income categories were identified.

SETTING

Molise region, Italy.

PARTICIPANTS

13 262 subjects (mean age 53±11, 50% men) out of 24 318 citizens (age ≥35) randomly enrolled in the Moli-sani Project.

MAIN OUTCOMES

Dietary patterns and risk factors for cardiovascular disease.

RESULTS

Household higher income were significantly associated with greater adherence to an MD (p<0.0001) and to Olive oil and Vegetables dietary pattern in a multivariable model including age, sex, daily energy intake, body mass index, physical activity, smoking, alcohol consumption, education and marital status. The odds of having the highest adherence to an MD clearly increased according to income levels. People having the highest income had 54% (95% CI 21% to 97%, MDS) or 72% (95% CI 34% to 121%, IMI) higher probability to stick to an MD-like eating pattern than those in the lowest-income group. Obesity prevalence was higher in the lowest-income group (36%) in comparison with the highest-income category (20%, p<0.0001). Income was associated with dietary patterns in all categories of education.

CONCLUSIONS

A higher income and education are independently associated with a greater adherence to MD-like eating patterns and a lower prevalence of obesity.

The quality and monetary value of diets consumed by adults in the United States

BACKGROUND

Food prices are an established determinant of food choice and may affect diet quality. Research on diet cost and diet quality in representative populations has been hindered by lack of data.

OBJECTIVE

We sought to explore the distribution of diet cost and diet quality among strata of the US population and to examine the association between the 2 variables.

DESIGN

In this cross-sectional study, monetary costs of diets consumed by participants in the 2001-2002 NHANES were estimated with the use of a national food price database. Healthy Eating Index (HEI)-2005 values were estimated with the use of the population ratio method for the calculation of average scores. Mean daily diet costs, energy-adjusted diet costs, and HEI-2005 scores were estimated for subpopulations of interest. Associations between energy-adjusted diet cost, HEI-2005 scores, and HEI-2005 component scores were evaluated.

RESULTS

Higher energy-adjusted diet costs were significantly associated with being older and non-Hispanic white, having a higher income and education, and living in a food-secure household. Higher diet costs were also associated with higher HEI-2005 scores for both men and women. Women in the highest quintile of diet costs had a mean HEI-2005 score of 69.6 compared with 52.5 for women in the lowest-cost quintile. Higher diet cost was strongly associated with consuming more servings of fruit and vegetables and fewer calories from solid fat, alcoholic beverages, and added sugars.

CONCLUSION

Given the observed association between diet cost and diet quality, helping consumers select affordable yet nutritious diets ought to be a priority for researchers and health professionals.

Dietary diversity and food expenditure as indicators of food security in older Taiwanese

Food quality is a measure of food security in vulnerable groups. The elderly are often nutritionally vulnerable, but how much of this is reflected in food quality and determined by financial status is unclear. We determined whether expenditure on dietary quality challenges food security in the aged. We used the representative Elderly Nutrition and Health Survey in Taiwan during 1999-2000 (n=1783), and evaluated dietary quality by a Dietary Diversity Score (DDS, range: 0-6) based on a 24-h dietary recall. Monthly mean national food prices were used to estimate food expenditure. In general, it was found to cost more to achieve a greater DDS. The food expenditure of subjects whose DDS=6 was 2.20 times greater than the DDS ≤3 group, after controlling for covariates. Elders of lower socioeconomic status tended to choose foods which would have cost less. However, a sub-group of elders who achieve the highest DDS with limited money offer approaches to food-money management. Nutrition policy directed to food insecure groups, like the aged, could employ health promotion strategies which reduce financial barriers to healthy eating.

Does diet cost mediate the relation between socioeconomic position and diet quality?

BACKGROUND/OBJECTIVES

Socioeconomic disparities in diet quality are well established. This study tested the hypothesis that such disparities are mediated, in part, by diet cost.

SUBJECTS/METHODS

The Seattle Obesity Study (S.O.S) was a cross-sectional study based on a representative sample of 1266 adults of King County, WA, conducted in 2008-09. Demographic and socioeconomic variables were obtained through telephone survey. Income and education were used as indicators of socioeconomic position. Dietary intake data were obtained using a food frequency questionnaire (FFQ). Diet cost was calculated based on retail prices for FFQ component foods. Energy density (KJ/g) and mean adequacy ratio (MAR) were used as two indices of overall diet quality.

RESULTS

Higher income and education were each associated with lower energy density and higher MAR scores, adjusting for covariates. Higher income and education were also associated with higher energy adjusted diet cost. Higher quality diets were in turn associated with higher diet costs. All these associations were significant (P<0.0001). In formal mediation analyses, diet cost significantly mediated the pathway between income and diet quality measures, adjusting for covariates (P<0.05 each). Further, income-diet cost-diet quality pathway was found to be moderated by education level.

CONCLUSIONS

The social gradient in diet quality may be explained by diet cost. Strategies to improve diet quality among lower socioeconomic strata may need to take food prices and diet cost along with nutrition education into account.

More nutritious food is served in child-care homes receiving higher federal food subsidies

The US Department of Agriculture's Child and Adult Care Food Program (CACFP) serves 2.3 million children by providing monetary subsidies for food to participating child-care providers. This cross-sectional study tested the hypothesis that higher reimbursement rates for food result in higher food expenditures and higher nutritional quality of foods served in family child-care homes participating in CACFP. Sixty family home child-care providers were recruited in 2008-2009 from King County, Washington. Half the sample received higher reimbursements and the other half received the lower rates. Participants provided a 5-day menu of meals/snacks served and food shopping receipts. The nutritional quality of foods served was assessed from portion-standardized menus. Nutritional quality was quantified as the mean adequacy (mean percent of dietary reference intake) for seven nutrients of concern for child health. Food expenditures were calculated by linking menus with receipts. Student's t tests for independent samples and general linear models were used to test for between-group differences. The two groups of providers were socioeconomically and demographically similar with comparable professional backgrounds. However, higher reimbursement providers had significantly greater menu expenditures than the lower reimbursement group ($2.36 vs $1.96/child/day; P=0.031). Reimbursement level was not associated with a difference in calories, but menus of higher reimbursement providers showed a significantly higher mean nutritional adequacy (64.5% vs 56.3%; P=0.033). The finding that reimbursement rates were positively associated with food expenditures and the nutritional quality of foods served suggests that raising CACFP reimbursements can improve child nutrition.

Nutritional strategies for successful aging

With increasing life expectancy in developed and developing countries, maintaining health and function in old age has become an important goal, including avoidance or optimal control of chronic diseases; maintenance or retarding the decline of physical and cognitive function; optimizing psychological health; and maintaining independent functioning in tasks related to self-care and societal interaction. This article discusses all of those, as well as other components of successful aging such as social network and socioeconomic status.

Trends in the prevalence, awareness, treatment, and control of cardiovascular risk factors across educational level in the 1995-2005 period

PURPOSE

To determine the differences and trends in the prevalence, awareness, treatment and control of cardiovascular risk factors and lifestyle variables across educational level in the 1995-2005 period in a country with a universal free health care system.

METHODS

Data from three consecutive independent population-based surveys were used. Cardiovascular risk factors, lifestyle variables, and self-reported educational level were collected in 9646 individuals ages 35-74 years throughout the decade.

RESULTS

The prevalence of hypertension and diabetes was inversely associated with education. An increase in the proportion of hypertension and dyslipidemia awareness, treatment, and control in all educational level groups was observed. This increase was greater among the lowest education group, reducing the disparities between groups. The prevalence of lifestyle-related risk factors decreased in the greatest but increased in the lowest education group, widening the disparities between groups.

CONCLUSIONS

A universal free health care system is effective in avoiding inequalities in the diagnosis, treatment, and control of cardiovascular risk factors. However, other social determinants seem to explain the social inequalities in the prevalence of these risk factors and in the adoption of healthy lifestyles.

Diet cost, diet quality and socio-economic position: how are they related and what contributes to differences in diet costs?

OBJECTIVE

To examine diet costs in relation to dietary quality and socio-economic position, and to investigate underlying reasons for differences in diet costs.

DESIGN

Dietary intake was assessed by a 4 d food diary and evaluated using the 2005 Healthy Eating Index (HEI). National consumer food prices collected by Statistics Sweden and from two online stores/supermarkets were used to estimate diet costs.

SETTING

Sweden.

SUBJECTS

A nationally representative sample of 2160 children aged 4, 8 or 11 years.

RESULTS

Higher scores on the HEI resulted in higher diet costs and, conversely, higher diet costs were linked to increased total HEI scores. Children who consumed the most healthy and/or expensive diets ate a more energy-dilute and varied diet compared with those who ate the least healthy and/or least expensive diets. They also consumed more fish, ready meals and fruit. Regression analysis also linked increased food costs to these food groups. There was a positive, but weak, relationship between HEI score and diet cost, parental education and parental occupation respectively.

CONCLUSIONS

Healthy eating is associated with higher diet cost in Swedish children, in part because of price differences between healthy and less-healthy foods. The cheapest and most unhealthy diets were found among those children whose parents were the least educated and had manual, low-skill occupations. Our results pose several challenges for public health policy makers, as well as for nutrition professionals, when forming dietary strategies and providing advice for macro- and microlevels in society.

Are socio-economic disparities in diet quality explained by diet cost?

BACKGROUND

Socio-economic disparities in nutrition are well documented. This study tested the hypothesis that socio-economic differences in nutrient intakes can be accounted for, in part, by diet cost.

METHODS

A representative sample of 1295 adults in King County (WA) was surveyed in 2008-2009, and usual dietary intakes were assessed based on a food-frequency questionnaire. The monetary value of individual diets was estimated using local retail supermarket prices for 384 foods. Nutrients of concern as identified by the 2005 Dietary Guidelines Advisory Committee were fibre, vitamins A, C and E, calcium, magnesium and potassium. A nutrient density score based on all seven nutrients was another dependent measure. General linear models and linear regressions were used to examine associations among education and income, nutrient density measure and diet cost. Analyses were conducted in 2009-2010.

RESULTS

Controlling for energy and other covariates, higher-cost diets were significantly higher in all seven nutrients and in overall nutrient density. Higher education and income were positively and significantly associated with the nutrient density measure, but these effects were greatly attenuated with the inclusion of the cost variable in the model.

CONCLUSIONS

Socio-economic differences in nutrient intake can be substantially explained by the monetary cost of the diet. The higher cost of more nutritious diets may contribute to socio-economic disparities in health and should be taken into account in the formulation of nutrition and public health policy.

Relation of food cost to healthfulness of diet among US women

BACKGROUND

Few studies have evaluated the cost of a diet that may prevent cardiovascular disease. High scores on the Alternative Healthy Eating Index (AHEI) have been associated with lower rates of cardiovascular disease.

OBJECTIVE

We sought to evaluate the cost of a dietary pattern that may prevent cardiovascular disease among women residing in the United States.

DESIGN

By using food-cost data from the US Department of Agriculture, we explored relations between spending on food and AHEI scores among 78,191 participants in the Nurses' Health Study. By using linear regression, we estimated the change in AHEI score (range: 2.5-87.5) for a $1 increase in spending on various food groups.

RESULTS

Study participants in the highest energy-adjusted spending quintile spent 124% as much money each day as those in the lowest quintile. The difference in AHEI scores (10th-90th percentile) between all study participants was 30 index points (Spearman's correlation coefficient between total spending and AHEI = 0.44). The difference in AHEI scores (10th-90th percentile) within each quintile of spending ranged from 25 to 29 index points. Greater spending on nuts, soy and beans, and whole grains was associated with a higher AHEI score. Greater spending on red and processed meats and high-fat dairy was associated with a lower AHEI score.

CONCLUSIONS

Although spending more money was associated with a healthier diet, large improvements in diet may be achieved without increased spending. The purchase of plant-based foods may offer the best investment for dietary health.

A healthy diet consistent with Australian health recommendations is too expensive for welfare-dependent families

OBJECTIVE

Examine the cost of healthy food habits for welfare-dependent families in Australia.

METHOD

A seven-day meal plan was developed, based on Australian public health recommendations, for two typical welfare-dependent families: a couple-family (two adults, two children) and a one-parent family (one adult, two children). The cost of the meal plan was calculated using market brand and generic brand grocery items, and total cost compared to income.

RESULTS

In Australia, the cost of healthy food habits uses about 40% of the disposable income of welfare-dependent families. Families earning an average income would spend only 20% of their disposable income to buy the same healthy food. Substituting generic brands for market brands reduced the weekly food cost by about 13%. This is one of few economic models to include generic brands.

CONCLUSION

Compared with average-income Australian families, healthy food habits are a fiscal challenge to welfare-dependent families.

IMPLICATIONS

These results provide a benchmark for economic and social policy analysis, and the influence disposable income has on prioritising healthy food habits.

Diet quality and obesity in women: the Framingham Nutrition Studies

Obesity affects one in three American adult women and is associated with overall mortality and major morbidities. A composite diet index to evaluate total diet quality may better assess the complex relationship between diet and obesity, providing insights for nutrition interventions. The purpose of the present investigation was to determine whether diet quality, defined according to the previously validated Framingham nutritional risk score (FNRS), was associated with the development of overweight or obesity in women. Over 16 years, we followed 590 normal-weight women (BMI < 25 kg/m2), aged 25 to 71 years, of the Framingham Offspring and Spouse Study who presented without CVD, cancer or diabetes at baseline. The nineteen-nutrient FNRS derived from mean ranks of nutrient intakes from 3 d dietary records was used to assess nutritional risk. The outcome was development of overweight or obesity (BMI > or = 25 kg/m2) during follow-up. In a stepwise multiple logistic regression model adjusted for age, physical activity and smoking status, the FNRS was directly related to overweight or obesity (P for trend = 0.009). Women with lower diet quality (i.e. higher nutritional risk scores) were significantly more likely to become overweight or obese (OR 1.76; 95 % CI 1.16, 2.69) compared with those with higher diet quality. Diet quality, assessed using a comprehensive composite nutritional risk score, predicted development of overweight or obesity. This finding suggests that overall diet quality be considered a key component in planning and implementing programmes for obesity risk reduction and treatment recommendations.

Are the lowest-cost healthful food plans culturally and socially acceptable?

OBJECTIVE

Nutritious yet inexpensive foods do exist. However, many such foods are rejected by the low-income consumer. Is it because their use violates unspoken social norms? The present study was designed to assess the variety and cost of the lowest-cost market basket of foods that simultaneously met required dietary standards and progressively stricter consumption constraints.

DESIGN

A mathematical optimisation model was used to develop the lowest-cost food plans to meet three levels of nutritional requirements and seven levels of consumption constraints.

SUBJECTS

The nationally representative INCA (National Individual Survey of Food Consumption) dietary survey study of 1332 adults provided population estimates of food consumption patterns in France. Food plan costs were based on retail food prices.

RESULTS

The lowest-cost food plans that provided 9204 kJ/d (2200 kcal/d) for men and 7531 kJ/d (1800 kcal/d) for women and met specified dietary standards could be obtained for <1.50 euro/d. The progressive imposition of consumption constraints designed to create more mainstream French diets sharply increased food plan costs, without improving nutritional value.

CONCLUSIONS

Minimising diet costs, while meeting nutrition standards only, led to food plans that provided little variety and deviated substantially from social norms. Aligning the food plan with mainstream consumption led to higher costs. Food plans designed for low-income groups need to be socially acceptable as well as affordable and nutritious.

Monetary cost of self-reported diet in relation to biomarker-based estimates of nutrient intake in young Japanese women

Objective

All previous studies on monetary diet cost have examined the relationship of monetary cost of self-reported diet to self-reported, rather than biomarker-based, estimates of dietary intake. The present cross-sectional study examined the association between monetary costs of self-reported diet and biomarker-based estimates of nutrient intake.

Design

Monetary diet cost (Japanese yen/1000 kJ) was calculated based on dietary intake information from a self-administered, comprehensive diet history questionnaire using retail food prices. Biomarker-based estimates of nutrient intake (percentage of energy for protein and mg/1000 kJ for K and Na) were estimated based on 24 h urinary excretion and estimated energy expenditure.

Setting

A total of fifteen universities and colleges in Japan.

Subjects

A total of 1046 female Japanese dietetic students aged 18–22 years.

Results

Total monetary diet cost showed a significant positive association with biomarker-based estimates of protein, K and Na. Vegetables and fish were not only the main contributors to total monetary diet cost (16·4 % and 15·5 %, respectively) but also were relatively strongly correlated with total monetary diet cost (Pearson’s correlation coefficient: 0·70 and 0·68, respectively). Monetary cost of vegetables was significantly positively associated with all three nutrients, while that of fish showed a significant and positive association only with protein.

Conclusions

Total monetary cost of self-reported diet was positively associated with biomarker-based estimates of protein, K and Na intake in young Japanese women, and appeared mainly to be explained by the monetary costs of vegetables and fish.

Monetary Diet Cost is Associated with not only Favorable but also Unfavorable Aspects of Diet in Pregnant Japanese Women: The Osaka Maternal and Child Health Study

While several observational studies in European countries have shown that higher monetary diet cost is associated with healthier diets, information on the relationship of cost to diet quality in other countries is sparse, including Japan. This cross-sectional study examined the association between monetary diet cost and dietary intake in a group of pregnant Japanese women. Subjects were 596 pregnant Japanese housewives. Dietary intake was estimated using a validated, self-administered, comprehensive diet history questionnaire. Monetary diet cost was calculated using retail food prices. Values of monetary diet cost and nutrient and food intake were energy-adjusted using the density method. Monetary diet cost was associated positively with the intake of protein, total fat, saturated fatty acids, dietary fiber, cholesterol, sodium, potassium, calcium, magnesium, iron, vitamins A, D, E, C, and folate, and inversely with that of carbohydrate. For foods, cost was associated positively with the intake of potatoes, pulses and nuts, fish and shellfish, meat, dairy products, vegetables, and fruits, and inversely with that of rice and bread. No association was seen for noodles, confectioneries and sugars, fats and oils, or eggs. Cost was also associated inversely with dietary energy density. In conclusion, monetary diet cost was associated with not only favorable aspects of diet, including a higher intake of dietary fiber, key vitamins and minerals, fruits, and vegetables and lower dietary energy density, but also unfavorable aspects, including a higher intake of fat and sodium and lower intake of carbohydrate and rice, in a group of pregnant Japanese women.

Lower-energy-density diets are associated with higher monetary costs per kilocalorie and are consumed by women of higher socioeconomic status

OBJECTIVE

Diets of lower energy density are associated with higher diet quality, lower body weights, and better health outcomes. This study examined associations among dietary energy density, energy-adjusted diet costs, and socioeconomic indicators of study participants.

DESIGN

In this cross-sectional study, energy and nutrient intakes for 164 men and women aged 25 to 65 years were obtained using a food frequency instrument between June 2005 and September 2006. Dietary energy density (kcal/g) was calculated with and without beverages. Energy-adjusted diet costs ($/2,000 kcal) were calculated using food prices in Seattle, WA. Tertile splits of energy density and energy cost were analyzed using tests for linear trend. Linear regression models tested the association between education, income, and dietary variables, adjusting for age and sex.

RESULTS

Diets of lower energy density were associated with higher absolute nutrient intakes. Diets of lower energy density were also associated with higher energy-adjusted diet costs. Conversely, highest energy density diets were associated with lower intakes of micronutrients and fiber and lower costs. Education and household income showed a negative association with dietary energy density in regression models. Education and household incomes showed a positive association with the energy-adjusted cost of the diet. Education was a stronger predictor of both energy density and energy cost than was household income.

CONCLUSIONS

Higher-quality diets were not only more costly per kilocalorie but were also consumed by persons of higher educational level. The influence of diet quality on health, observed in some epidemiologic studies, might be modulated by unobserved indexes of socioeconomic status.

Cost of compliance with daily recommended values of micronutrients among a cohort of Spanish university graduates: the SUN (Seguimiento Universidad de Navarra) Study

OBJECTIVE

Previous studies have shown that highly nutritious diets are more costly, but to date there has been no evaluation of the costs associated with failing to meet micronutrient recommendations in a Spanish population.

DESIGN, SETTING AND SUBJECTS

We examined whether daily food consumption costs (classified in quintiles) were associated with failing to meet at least three daily nutritional recommendations out of twenty (including fibre and nineteen micronutrients) in a cross-sectional analysis of baseline data of a cohort of 17,197 Spanish university graduates. Micronutrients and fibre intake were assessed with a validated 136-item FFQ. Average cost of food was calculated from official Spanish government data.

RESULTS AND CONCLUSIONS

As participants presented higher dietary energy cost from their diet, their intake of micronutrients increased significantly. Low dietary energy cost was associated with a higher likelihood of failing to meet three or more recommendations (P for trend <0.001 across quintiles of dietary cost), the association being stronger among female than male participants (P for interaction between sex and quintile of dietary energy cost <0.001).

Monetary cost of dietary energy is negatively associated with BMI and waist circumference, but not with other metabolic risk factors, in young Japanese women

OBJECTIVE

Little is known about the relationship of dietary cost to health status. The present cross-sectional study examined the association between the monetary cost of dietary energy (Japanese yen/4184 kJ) and several metabolic risk factors.

DESIGN

Monetary cost of dietary energy was estimated based on dietary intake assessed by a self-administered diet history questionnaire and retail food prices. Body height and weight, from which BMI was derived, waist circumference and blood pressure were measured and fasting blood samples were collected for biochemical measurements.

SETTING

A total of fifteen universities and colleges in Japan.

SUBJECTS

A total of 1136 female Japanese dietetic students aged 18-22 years.

RESULTS

After adjustment for potential confounding factors, monetary cost of dietary energy was significantly and negatively associated with BMI (P for trend = 0.0024). Monetary cost of dietary energy also showed a significant and negative association with waist circumference independently of potential confounding factors, including BMI (P for trend = 0.0003). No significant associations were observed for other metabolic risk factors examined (P for trend = 0.10-0.88).

CONCLUSIONS

The monetary cost of dietary energy was independently and negatively associated with both BMI and waist circumference, but not other metabolic risk factors, in a group of young Japanese women.

Comparability of weighed dietary records and a self-administered diet history questionnaire for estimating monetary cost of dietary energy

An increasing number of studies have estimated monetary diet cost using various dietary assessment methods, based on databases on retail food prices, for investigating its association with dietary intake and health outcomes. However, information regarding the comparability of monetary diet cost across dietary assessment methods is absolutely lacking. This study compared monetary cost of dietary energy estimated from weighed dietary records (DRs) with that estimated from a self-administered diet history questionnaire (DHQ). The subjects were 92 Japanese women aged 31-69 years and 92 Japanese men aged 32-76 years. The DHQ (assessing diet during the preceding month) and 4-day DRs (one weekend day and three weekdays) were completed in each season over a 1-year period (DHQs1-4 and DRs1-4, respectively). An additional DHQ was completed at one year after completing DHQ1 (DHQ5). Monetary cost of dietary energy (Japanese yen/4184 kJ) was calculated using food intake information derived from each dietary assessment method, based on retail food prices. Pearson correlation between the mean of DRs1-4 and mean of DHQs1-4 was 0.64 for women and 0.69 for men. Pearson correlation between the mean of DRs1-4 and DHQ1 was 0.60 for women and 0.52 for men, while intraclass correlation between DHQ1 and DHQ5 was 0.64 for women and 0.51 for men. These data indicate reasonable comparability of monetary cost of dietary energy across DR and a DHQ as well as usefulness of a single administration of the DHQ for estimating monetary cost of dietary energy.

Nutrient profiling can help identify foods of good nutritional quality for their price: a validation study with linear programming

Nutrient profiling ranks foods based on their nutrient content. They may help identify foods with a good nutritional quality for their price. This hypothesis was tested using diet modeling with linear programming. Analyses were undertaken using food intake data from the nationally representative French INCA (enquête Individuelle et Nationale sur les Consommations Alimentaires) survey and its associated food composition and price database. For each food, a nutrient profile score was defined as the ratio between the previously published nutrient density score (NDS) and the limited nutrient score (LIM); a nutritional quality for price indicator was developed and calculated from the relationship between its NDS:LIM and energy cost (in euro/100 kcal). We developed linear programming models to design diets that fulfilled increasing levels of nutritional constraints at a minimal cost. The median NDS:LIM values of foods selected in modeled diets increased as the levels of nutritional constraints increased (P = 0.005). In addition, the proportion of foods with a good nutritional quality for price indicator was higher (P < 0.0001) among foods selected (81%) than among foods not selected (39%) in modeled diets. This agreement between the linear programming and the nutrient profiling approaches indicates that nutrient profiling can help identify foods of good nutritional quality for their price. Linear programming is a useful tool for testing nutrient profiling systems and validating the concept of nutrient profiling.

Does social class predict diet quality?

A large body of epidemiologic data show that diet quality follows a socioeconomic gradient. Whereas higher-quality diets are associated with greater affluence, energy-dense diets that are nutrient-poor are preferentially consumed by persons of lower socioeconomic status (SES) and of more limited economic means. As this review demonstrates, whole grains, lean meats, fish, low-fat dairy products, and fresh vegetables and fruit are more likely to be consumed by groups of higher SES. In contrast, the consumption of refined grains and added fats has been associated with lower SES. Although micronutrient intake and, hence, diet quality are affected by SES, little evidence indicates that SES affects either total energy intakes or the macronutrient composition of the diet. The observed associations between SES variables and diet-quality measures can be explained by a variety of potentially causal mechanisms. The disparity in energy costs ($/MJ) between energy-dense and nutrient-dense foods is one such mechanism; easy physical access to low-cost energy-dense foods is another. If higher SES is a causal determinant of diet quality, then the reported associations between diet quality and better health, found in so many epidemiologic studies, may have been confounded by unobserved indexes of social class. Conversely, if limited economic resources are causally linked to low-quality diets, some current strategies for health promotion, based on recommending high-cost foods to low-income people, may prove to be wholly ineffective. Exploring the possible causal relations between SES and diet quality is the purpose of this review.

The association of fast food, fruit and vegetable prices with dietary intakes among US adults: is there modification by family income?

We examined the effects of prices of fast foods and fruits and vegetables on dietary intake, body mass index (BMI) and obesity risks and whether the associations varied across groups according to their family income. Data from the US Department of Agriculture Continuing Survey of Food Intakes by Individuals (CSFII 1994-96) for 7331 individuals aged 20-65 years with complete data on two 24-h recalls were used. We computed two food price indices (FFPI and FVPI) which were linked to individuals through geocoded identifiers. Main outcomes included dietary intakes of energy, selected nutrients and food groups, fast food consumption, and diet quality measured using two indices (HEI and aMED), BMI and obesity. Interaction terms between key variables were tested in regression analyses and in further stratified analysis by family income. Higher fast food price indices (FFPIs) were associated with higher fiber intake, lower saturated fat, and better overall diet quality as measured by aMED. FVPI was positively associated with improved dietary quality as well as in terms of lower cholesterol and sodium intakes, improved HEI and lower BMI. Most of these associations showed homogeneous strengths across income groups as evidenced by a non-significant FFPIxPIR or FVPIxPIR interaction term (p>0.10). While increasing FFPI by 1 standard deviation was only borderline protective against fast food consumption, its association with other binary outcomes that were considered was non-significant. In contrast, FVPI was protective against obesity, particularly among the near poor. It was also associated with improved aMED score. Analyses of these national data suggest that changing fast food and fruit and vegetable prices may affect people's dietary quality and to some extent their adiposity, although the present study is limited by the available food price data.

The rising cost of low-energy-density foods

BACKGROUND

Consuming lower-energy-density foods is one recommended strategy for management of body weight. This cross-sectional study used retail food prices to test the hypothesis that low-energy-density foods are not only more costly per kilocalorie, but have increased disproportionately in price as compared to high-energy-density foods.

DESIGN

For a list of 372 foods and beverages belonging to a food frequency questionnaire database, retail prices were obtained from major supermarket chains in the Seattle, WA, metropolitan area in 2004 and 2006. Energy density of all items was calculated and prices were expressed as $/100 g edible portion and as $/1,000 kcal. Foods were stratified by quintiles of energy density and the differences in energy cost and in percent price change were tested using analyses of variance.

RESULTS

High-energy-density foods provided the most dietary energy at least cost. Energy cost of foods in the bottom quintile of energy density, beverages excluded, was $18.16/1,000 kcal as compared to only $1.76/1,000 kcal for foods in the top quintile. The 2-year price change for the least energy-dense foods was +19.5%, whereas the price change for the most energy-dense foods was -1.8%.

CONCLUSION

The finding that energy-dense foods are not only the least expensive, but also most resistant to inflation, may help explain why the highest rates of obesity continue to be observed among groups of limited economic means. The sharp price increase for the low-energy-density foods suggests that economic factors may pose a barrier to the adoption of more healthful diets and so limit the impact of dietary guidance.

A nutritional intervention promoting a Mediterranean food pattern does not affect total daily dietary cost in North American women in free-living conditions

The purpose of this study was to evaluate the impact of adopting a Mediterranean diet on dietary cost and energy density in free-living conditions. The 12-wk nutritional intervention consisted of 2 group courses and 7 individual sessions with a dietician in a sample of 73 healthy women. To evaluate the dietary response to the nutritional intervention, a registered dietician administered a FFQ at 0, 6, 12, and 24 wk. Total daily dietary cost was calculated using a price list including all items from the FFQ. Our findings indicated that daily energy cost evaluated at wk 12 vs. wk 0 [1046 +/- 217 vs. 967 +/- 192 kJ/Canadian dollars (CAN$), respectively, P = 0.18] and total daily dietary cost (8.61 +/- 2.13 vs. 8.75 +/- 2.50 CAN$/d per participant, respectively, P = 0.58) did not change. Total daily energy density at wk 12 decreased compared with wk 0 (2.56 +/- 0.76 vs. 2.20 +/- 0.67 kJ/g; P < 0.0001). Adherence to the Mediterranean diet led to increased cost related to vegetables, fruits, legumes, nuts and seeds, canola/olive oil, whole grains, poultry, and fish (P < or = 0.01) and to reduced dietary cost for red meat, refined grains, desserts and sweets, and fast food (P < or = 0.008). In conclusion, these data suggest that adherence to a nutritional intervention program promoting the Mediterranean food pattern is not associated with increased daily dietary cost or energy cost but led to a reduction in energy density. Consequently, increased cost should not be considered a barrier to the promotion and adoption of a Mediterranean diet.

Monetary costs of dietary energy reported by young Japanese women: association with food and nutrient intake and body mass index

Objective

Little is known about the relationship of monetary diet costs to dietary intake and obesity, particularly in non-Western populations. This study examined monetary cost of dietary energy in relation to diet quality and body mass index (BMI) among young Japanese women.

Design

Dietary intake was assessed by a validated, self-administered, diet history questionnaire. Diet costs were estimated using retail food prices. Monetary cost of dietary energy (Japanese yen 1000 kcal−1) was then calculated. BMI was computed from self-reported body weight and height.

Subjects

A total of 3931 female Japanese dietetic students aged 18–20 years.

Results

Monetary cost of dietary energy was positively associated with intakes of fruits, vegetables, fish and shellfish, and pulses; however, higher monetary cost of dietary energy was also associated with higher consumption of fat and oil, meat and energy-containing beverages, and lower consumption of cereals (rice, bread and noodles) (all P for trend <0.01). At the nutrient level, monetary cost of dietary energy was positively associated with intakes of dietary fibre and key vitamins and minerals, but also associated positively with intakes of fat, saturated fatty acids, cholesterol and sodium, and negatively with carbohydrate intake (all P for trend <0.0001). After adjustment for possible confounders, monetary cost of dietary energy was quite weakly but significantly negatively associated with BMI (P for trend = 0.0197).

Conclusions

Increasing monetary cost of dietary energy was associated with both favourable and unfavourable dietary intake patterns and a quite small decrease in BMI in young Japanese women.

Low-energy-density diets are associated with higher diet quality and higher diet costs in French adults

Low-energy-density diets are often recommended for weight control. Such diets have a higher nutrient content than do high-energy-density diets. This study tested the hypothesis that energy-dense diets have a relatively low monetary cost, whereas less energy-dense diets are more expensive. In this cross-sectional study, dietary intakes of 1,474 French adults (672 men, 802 women), aged 15 to 92 years, were assessed using 7-day diet records. Dietary energy density (kcal/g) was calculated by dividing total dietary energy by the edible weight of foods and caloric beverages consumed. Diet cost ($/7 days or $/2,000 kcal) was estimated using mean national food prices for 895 foods. The relationship between dietary energy density and diet cost was examined in a linear regression model. Within each quintile of energy intakes, the more energy-dense diets were associated with lower diet quality and with lower diet costs (r(2)=0.38 to 0.44). In a regression model, the more energy-dense diets cost less, whereas low-energy-density diets cost substantially more, adjusting for energy intakes, sex, and age. The finding that energy-dense diets cost less per 2,000 kcal may help explain why the highest rates of obesity are observed among groups of limited economic means. The finding that low-energy-density diets are associated with higher diet costs suggests that lasting improvements in diet quality may require economic as well as behavioral interventions.

How do socio-economic status, perceived economic barriers and nutritional benefits affect quality of dietary intake among US adults?

BACKGROUND

Socio-economic factors may affect diet quality, perhaps differentially across gender and ethnicity. The mechanism of this association is still largely unknown.

OBJECTIVES

We examined the independent effects of socio-economic status (SES), perceived barrier of food price (PBFP) and perceived benefit of diet quality (PBDQ) on diet quality indicators and indices (DQI(j,k)), across gender and ethnicity. Additionally, we estimated the mediation proportion of the effect of SES on DQI(j,k) through PBFP and PBDQ.

METHODS

Data from two cross-sectional surveys, the Continuing Survey of Food Intakes by Individuals (CSFII) and Diet and Health Knowledge Survey (DHKS) 1994-96 were used. Our sample consisted of 4356 US adults aged 20-65 years. With principal components analysis, SES (an index) was measured using household income per capita and education, and PBDQ was measured using an 11-item scale. PBFP was defined as the ratio of importance of food price score relative to nutrition. DQI(j,k) were assessed by a set of indicators and two indices including the Healthy Eating Index.

RESULTS

The associations between SES, PBFP, PBDQ and DQI(j,k) varied significantly across gender and ethnic groups. PBFP acted as a mediator in the association between SES and selected DQI(j) indicators, namely energy, fat intake, sodium and simple sugar consumption (mediation proportion >10%), but not PBDQ.

CONCLUSIONS

SES, PBFP and PBDQ all affect dietary intake, and vary by ethnicity and gender. Positive effect of SES on DQI(j,k) may be mediated by PBFP but not PBDQ which is an independent protective factor. Nutrition education is important to promote healthy eating.