To develop an index to assess the nutritional quality of household food purchases based on food expenditures only.

A database of monthly food purchases of a convenience sample of low-income households was used to develop the Healthy Purchase Index (HPI). The HPI is the sum of two sub-scores based on expenditure shares of food categories in total household food expenditure: the purchase diversity sub-score and the purchase quality sub-score. The first was adapted from an existing diversity score. The second integrated those food categories identified as the best predictors of the nutritional quality of purchases based on associations between expenditure shares of food categories and two nutritional quality indicators: the mean adequacy ratio (MAR) and the mean excess ratio (MER). Correlation between the HPI and a score assessing adherence to French dietary guidelines (PNNS-GSmod) was performed as a first validation.

Food purchases of 112 households from deprived neighbourhoods of Marseille (France), participating in the Opticourses and Jassur projects (2012–2015).

The purchase diversity sub-score reflects the presence in food purchases of five food categories: fruits, vegetables, starches, dairy products, and meat, fish & eggs. The purchase quality sub-score is based on expenditure shares for fruit & vegetables, added fats & seasonings, sweet snacks, cheese, sugary drinks, refined grains and fish, as these were identified as predictors of the nutritional quality of purchases. The HPI was positively associated with the PNNS-GSmod (rs=0·378; P<0·001).

The HPI helps assess the healthiness of household food purchases.

To identify optimal food choices that meet nutritional recommendations to reduce prevalence of inadequate nutrient intakes.

Linear programming was used to obtain an optimized diet with sixty-eight foods with the least difference from the observed population mean dietary intake while meeting a set of nutritional goals that included reduction in the prevalence of inadequate nutrient intakes to ≤20 %.

Brazil.

Participants (men and women, n 25 324) aged 20 years or more from the first National Dietary Survey (NDS) 2008–2009.

Feasible solution to the model was not found when all constraints were imposed; infeasible nutrients were Ca, vitamins D and E, Mg, Zn, fibre, linolenic acid, monounsaturated fat and Na. Feasible solution was obtained after relaxing the nutritional constraints for these limiting nutrients by including a deviation variable in the model. Estimated prevalence of nutrient inadequacy was reduced by 60–70 % for most nutrients, and mean saturated and trans-fat decreased in the optimized diet meeting the model constraints. Optimized diet was characterized by increases especially in fruits (+92 g), beans (+64 g), vegetables (+43 g), milk (+12 g), fish and seafood (+15 g) and whole cereals (+14 g), and reductions of sugar-sweetened beverages (−90 g), rice (−63 g), snacks (−14 g), red meat (−13 g) and processed meat (−9·7 g).

Linear programming is a unique tool to identify which changes in the current diet can increase nutrient intake and place the population at lower risk of nutrient inadequacy. Reaching nutritional adequacy for all nutrients would require major dietary changes in the Brazilian diet.

To assess the compatibility between reduction of diet-related greenhouse gas emissions (GHGE) and nutritional adequacy, acceptability and affordability dimensions of diet sustainability.

Dietary intake, nutritional composition, GHGE and prices were combined for 402 foods selected among those most consumed by participants of the Individual National Study on Food Consumption. Linear programming was used to model diets with stepwise GHGE reductions, minimized departure from observed diet and three scenarios of nutritional constraints: none (FREE), on macronutrients (MACRO) and for all nutrient recommendations (ADEQ). Nutritional quality was assessed using the mean adequacy ratio (MAR) and solid energy density (SED).

France.

Adults (n 1899).

In FREE and MACRO scenarios, imposing up to 30 % GHGE reduction did not affect the MAR, SED and food group pattern of the observed diet, but required substitutions within food groups; higher GHGE reductions decreased diet cost, but also nutritional quality, even with constraints on macronutrients. Imposing all nutritional recommendations (ADEQ) increased the fruits and vegetables quantity, reduced SED and slightly increased diet cost without additional modifications induced by the GHGE constraint up to 30 % reduction; higher GHGE reductions decreased diet cost but required non-trivial dietary shifts from the observed diet. Not all the nutritional recommendations could be met for GHGE reductions ≥70 %.

Moderate GHGE reductions (≤30 %) were compatible with nutritional adequacy and affordability without adding major food group shifts to those induced by nutritional recommendations. Higher GHGE reductions either impaired nutritional quality, even when macronutrient recommendations were imposed, or required non-trivial dietary shifts compromising acceptability to reach nutritional adequacy.

To examine the consumption of plain water among children in France and compare total water intakes with guidelines issued by the European Food Safety Authority (EFSA).

Nationally representative data were used to assess food, beverage and water consumption by sex, age group (4–8 years, 9–13 years), income-to-poverty ratio, eating occasion and location. Beverages were classified into nine groups: water (tap or bottled), milk, 100 % fruit juice, sodas, fruit drinks, hot beverages, sports drinks and flavoured waters. Total water volume in relation to energy intake (litres/kcal) was also examined.

INCA 2 study (Étude Individuelle Nationale des Consommations Alimentaires 2006–2007).

French children (n 835) aged 4–13 years.

Total water intakes were accounted for by plain water (34 %), beverages (26 %) and food moisture (40 %). Plain water could be tap (18 %) or bottled (16 %). Older children drank more plain water than did younger children and boys drank more plain water than did girls. No socio-economic gradient for plain water consumption was observed. About 90 % of children did not meet the EFSA water intake recommendations. The daily water shortfall ranged from 367 to 594 ml/d. Water-to-energy ratio was 0·75–0·77 litres/1000 kcal (4184 kJ). Children drank milk at breakfast and plain water during lunch and dinner. Caloric beverages provided 10 % of dietary energy; consumption patterns varied by eating location.

Total water intakes among young children in France were below EFSA-recommended levels. Analyses of beverage consumption patterns by eating occasion and location can help identify ways to increase water consumption among children.

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.

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.

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.

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 €/d. The progressive imposition of consumption constraints designed to create more mainstream French diets sharply increased food plan costs, without improving nutritional value.

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.

Consumers are increasingly relying on low-cost foods, although it is not clear if the nutritional quality of these foods is fully maintained. The aim of the present work was to analyse the relationship between cost and quality within a given food category.

The relationship was analysed between nutritional quality and cost for 220 food products belonging to seventeen different categories, controlling for package type and package size. Given that a summary of nutrient information was not available on the product label, a novel ingredient quality score was developed based on listed product ingredients.

Within a given category, the lowest-priced foods were not different from the equivalent branded products in terms of overall energy or total fat content. Nevertheless, a positive relationship, small but significant, was observed between the price and the ingredient quality score. On average, the branded products cost 2·5 times more than the low-cost products, for an equivalent energy and lipid content, and had a slightly higher (1·3 times) ingredient quality score.

More studies are necessary to evaluate the nutritional quality of low-cost foods. This evaluation would be facilitated if nutrition labelling was mandatory. Yet in view of the present results, it does not seem to be justified to divert consumers, especially the poorest, from low-cost foods because this may have an adverse effect on the nutritional quality of their diet, by reducing further the fraction of their food budget spent on fresh fruit and vegetables.