This is a community project performed in the neighborhood of Santa Fe, Mexico City. It was conducted from January 2022 to June 2022. The sample was selected using a convenience sampling method. The targeted population belonged to a low socioeconomic status, who live close to the Community Center “Centro Ibero Meneses” (Fig. 1), which is situated in an underserved area. This approach was chosen for its practicality and ease of access to participants. By focusing on families near the community center, the study aimed to ensure a representative sample from the local population in Santa Fe. Upon arrival at the Community Center, participants received a complete explanation of the program, and the head of the family was asked to provide informed consent to participate in this study. Subsequently, participants were asked to complete three distinct questionnaires, each serving a specific purpose and gathering diverse information related to sodium intake and family habits.

Fig. 1

Neighborhoods of the families with regards to the distance to Meneses Center and Iberoamericana University

General questionnaire

The general questionnaire was administered to one member from each of the 35 families in order to gather information about their sociodemographic and socioeconomic characteristics. The questionnaire included inquiries about who cooks the meals, what ingredients are used, the size and composition of their family, the age of each family member, the number of individuals who eat at home, and details about who is responsible for purchasing ingredients and foods, where the foods are bought (such as supermarkets, local markets, wet markets, small neighborhood stores), and how often they go shopping for food. Additionally, the questionnaire included questions about the participants’ knowledge of the relationship of sodium and health and whether anyone in their family lives with a non-communicable disease such as hypertension, type 2 diabetes, or overweight/obesity.

24-hour dietary recall

To collect 24-hour multi-step recall data, the ASA24 tool developed by the National Cancer Institute (NCI) was utilized. This automated website allows for the detailed capture of food and beverage consumption within the last 24 h, from midnight of the application day to midnight of the previous day. The project started by registering all participant folios in the ASA24 web system. Subsequently, the ASA24 tool was applied to participants via telephone, following a series of steps. This questionnaire allows participants to understand and describe their dietary habits and nutrient intake.

After collecting the participants’ diet data through the 24-hour recall, foods and food products were classified using the NOVA classification system, which groups them based on the extent and purpose of processing and consists of four groups [13]. Group 1 includes unprocessed or minimally processed foods, which are natural foods altered only through processes like drying or cooking. Group 2 comprises processed culinary ingredients obtained from foods or nature like salt and sugar. Group 3 consists of processed foods made by adding substances like sugar or salt to Group 1 foods. Finally, Group 4 includes ultra-processed products, which are industrial formulations with numerous ingredients added to processed substances, including additives [13].

Sodium excretion in 24-hour urine

After administering the questionnaires, participants were shown a detailed video explaining how the 24-hour urine samples needed to be collected. They were then provided with sterilized containers to collect their urine samples. To determine the levels of sodium (Na) and potassium (K) in the urine, the samples were analyzed with the method of reflectance spectrophotometry. This technique is based on studying the behavior of electromagnetic waves emitted, absorbed, and reflected by a solid, liquid, or gas. It is commonly used for the identification of certain compounds and minerals such as Na and K [14].

Family garden with aromatic herbs

Traditional Mexican cuisine is known for its use of various spices, condiments, and herbs to enhance the flavors of dishes [15]. As a result, a selection of herbs that can be used as alternatives to salt or seasoning powder were identified. Eight herbs, including parsley, oregano, chives, rosemary, cilantro, thyme, fennel, and basil, have been recommended as salt replacements [16]. These herbs not only add flavor but also stimulate the senses and digestive glands, contributing to better assimilation. They are used to enhance aromas, add spiciness and color to dishes, and some may even have antioxidant properties. With the experience of researchers working at “Huerto Ibero” a family garden with six herbs was designed based on adaptable plants for the microclimates of Mexico City, including cilantro, oregano, thyme, epazote, chives, and basil, in containers using a specific substrate mixture (Fig. 2). This family garden was given to each participant which helped them to harvest fresh herbs that can enhance the flavors and taste of Mexican dishes. Each garden had a cost of $300 Mexican pesos (around $15 US dollars).

Fig. 2

Family Garden illustration

Workshops

Participants were given 7 cooking workshops via Zoom Video Communications Inc. (Zoom), each focused on preparing a dish using one of the herbs from the garden. The first workshop focused on the general introduction to the project and the cooking sessions, where a video was played explaining the importance of sodium, its sources, and the consequences of excessive consumption (Video 1). The subsequent workshops featured specific recipes, starting with a bean salad with basil vinaigrette and a pamphlet highlighting the nutritional properties of beans and basil, as well as a presentation on the new labeling regulations introduced in NOM-051 [10]. The second recipe was cilantro chicken, followed by esquites (a Mexican corn dish) with epazote, including information on the benefits of corn and epazote. The fifth workshop focused on making Chinese-style rice with chives, along with a session on proper food disinfection and the properties of eggs and chives. The second to last workshop featured celery soup with oregano, highlighting the properties of oregano and celery. Finally, the last recipe was a thyme-infused chicken, along with a pamphlet with information about the properties of thyme.

Lastly, they received 3 workshops also via Zoom on garden care, including topics such as selecting the appropriate soil for planting, understanding the different parts of a plant, where to find seeds, determining the spacing requirements for each plant, transplanting plants as they grow, watering and pruning frequency, knowing when the herbs are ready to be used, and addressing pest issues that may arise, among other subjects.

Cooking recipe book

At the end of the workshops, participants were given a cookbook containing over 300 recipes created by four independent nutritionists specifically for the project. These recipes featured reduced sodium content of typical Mexican dishes, with sodium being replaced by various herbs from the family garden. The cookbook included a wide range of recipes, including beverages, appetizers, main courses, sauces and dressings, desserts, basic culinary techniques, and information about cooking methods, properties of herbs and spices, as well as infographics providing tips on reducing sodium consumption and understanding the sources of salt in our diets. The recipes used during the cooking workshops were sourced from this cookbook. The cost of printing each recipe book was $250 Mexican pesos (around $12.50 US dollars).

Involvement with the families

There was constant communication with the families to answer any questions or concerns related to the intervention, providing information to them by an expert on garden care, three nutritionists, and the main researcher of the project. They were encouraged to ask any questions they had and were given the freedom to share recipes using aromatic herbs, as well as photos, videos or media of the dishes they prepared in the workshops and the growth and care of their own family garden.

Direct measurement

Direct measurement involved quantifying the amount of salt and/or seasoning powder added to cooking in the households [4]. Each family household was visited and the person responsible for food preparation was asked to show the amount of salt and/or seasoning powder added to the meal on daily basis. The amount used was weighed using the Ohaus Scout Pro electronic scale and divided among the family members to determine individual sodium consumption.

For the further households from the Community Center, an online questionnaire was sent to request the quantity and frequency of salt and/or seasoning powder purchased. The amount purchased was then divided by the number of days between purchases and further divided by the number of family members. For example, if they purchased 1 kg of salt every 6 months, it would be divided as follows: 1000 g / 180 days by family = 5.5 g / 4 family members = 1.38 g of salt per person per day [4].

Home food inventory

A validated instrument from the United States for Spanish-speaking families was used, which includes a list of common foods, beverages, and products found in the Mexican population’s pantry, refrigerator, and freezer. This instrument has shown that food availability in the household is significantly associated with dietary practices, intake, and eating patterns [17].

The qualitative data of the project was gathered through the storytelling method. It is an inherent element of human culture, and it has emerged as a valuable tool for gathering research data and developing multidisciplinary interventions [18].

It is important to highlight that due to the COVID-19 pandemic, some activities were adapted to an online format, utilizing platforms such as Zoom for conducting the workshops. Additionally, certain questionnaires, such as the 24-hour dietary recall, were administered via telephone to ensure the safety of the participants and collaborators.

In this study, for the purpose of translation and ensuring grammatical accuracy, the ChatGPT language model was utilized. ChatGPT was employed to aid in translating and refining specific paragraphs of the paper. Its advanced language capabilities were harnessed to enhance the clarity and coherence of the content, ensuring that the ideas and concepts presented maintain their integrity across languages.