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Is it possible to improve the food supply of people having to face financial difficulties, while taking into account both nutritional quality and food price? According to a new study from the French Institute of Agronomic Research, the answer is yes, based on more than five years of research in poor neighborhoods of Marseille in southern France.

The least expensive foods are often the highest in calories and lowest in essential nutrients, which makes achieving nutritional balance more difficult for people with strong budgetary constraints. A strict minimum of 3.50 euros per person, per day is estimated as being necessary for covering nutritional needs. Scientists have shown that by selecting groups of foods and foods of good nutritional quality for their price, it is theoretically possible to improve the relationship between nutritional quality and price of foods for people with budgetary constraints.

Researchers conducted an interventional and participatory study. In the first phase of research, a sample of 96 people participated with the researchers and local actors (care centers, welfare centers, etc.) on building intervention and evaluation tools for a preventive program based on real purchases of the people involved. Then, in a second phase, research was done with 93 residents, and its impact evaluated.


The prevention program Opticourses consists of five two-hour long workshops, spaced 15 days apart. The workshops are based on fun activities and concrete tools around the practices of food purchases on nutritional quality and the price of food. They are supported in particular by receipts the participants are asked to record for one month, in a booklet presenting foods of high nutritional quality and their price, on blind taste tests of foods from discount brands, supermarket brands and nationally distributed brands.

The impact of participating in these workshops on the purchasing behavior of participants was evaluated with the help of game (conducted at the end of the workshops, and by a control group that hadn’t participated in the workshops) in which participants were asked to make a two-day shopping list using a catalogue presenting photos of 300 products and their prices. The participants are informed that they can receive a 10-euro gift card if they actually make their purchases in a real store, submitting their receipts as proof. This encourages the participants to indicate their real preferences.

The results of this analysis showed that the participation in the workshops leads to a substantial decrease, of statistical significance, of calories purchases (around 3,000 versus more than 5,000 calories for the control group per day and per person) in the simulated shopping carts of the participants. The study demonstrates an increase of a factor of 1.4 in the percentage of fruits and vegetables purchases, and a decrease by a factor of two of products of high fat, salt and sugar content. And these purchases were not associated with an increase in the amount of money spent. Three other changes in behaviors were also noted: on the types of foods purchased, purchasing strategies and cooking practices.

In total, these results demonstrate well that these participative workshops favorably changed the food purchasing behavior of low-income participants without significantly increasing their food expenses. The long-term effects of these workshops will be studied in later research.