The population has more and more information about the importance of eating habits for a healthy life(Reference Herforth, Arimond and Álvarez-Sánchez1). However, the current high prevalence of overweight and obesity in childhood(Reference Di Cesare, Sori and Bovet2) and other chronic conditions such as metabolic syndrome(Reference Weiss, Dziura and Burgert3) suggests that, among other factors, there is a gap between the information available and the dietary habits, especially the consumption of plant-based foods(Reference Lynch, Kristjansdottir and Velde4,Reference De Craemer, Van Stappen and Brondeel5) . One of the factors that has been identified as a barrier to maintaining a healthy diet is limited knowledge, skills and abilities related to home cooking(Reference Mills, White and Brown6). In addition, the home environment has a strong influence on the development and maintenance of children’s eating habits(Reference Mahmood, Flores-barrantes and Moreno7). Indeed, parental attitudes, beliefs, behaviours and decisions can influence children’s dietary choices(Reference Larsen, Hermans and Sleddens8,Reference Jilani, Pohlabeln and Buchecker9) , as well as the development of childhood overweight(Reference Sokol, Qin and Poti10,Reference Shloim, Edelson and Martin11) .
Family-focused public health is based on the idea that health begins at home, and the family environment has a relevant role in the healthy development of children at primary, secondary and tertiary prevention levels(Reference Hanson, Crandall and Barnes12). In fact, previous studies have demonstrated that family-based nutrition interventions can improve health and dietary habits(Reference Black, D’Onise and McDermott13). Dietary interventions aiming to improve the consumption of plant-based foods among children have reported a positive effect on increasing vegetables and fruits(Reference Matthan, Wylie-Rosett and Xue14,Reference Calvo-Malvar, Benítez-Estévez and Leis15) while others did not(Reference Arenaza, Oses and Amasene16). In this context, promoting home cooking can be an effective strategy for chronic disease prevention and health promotion(Reference Quelly17–Reference Muzaffar, Metcalfe and Fiese19) by improving children’s dietary habits(Reference Overcash, Ritter and Mann20–Reference Varagiannis, Magriplis and Risvas23). However, most of these studies have been conducted in the USA(Reference Overcash, Ritter and Mann20–Reference Razavi, Sapin and Monlezun22,Reference Robson, Stough and Stark24–Reference Saxe-Custack, Lachance and Hanna-Attisha26) , with short follow-up (<3 months)(Reference Overcash, Ritter and Mann20,Reference Razavi, Sapin and Monlezun22,Reference Robson, Stough and Stark24,Reference Saxe-Custack, Lachance and Hanna-Attisha26–Reference Lavelle, Mooney and Coffey28) and a limited information about the dietary changes among parents and children(Reference Saxe-Custack, Lachance and Hanna-Attisha26–Reference Ng, Kaur and Koo29). In person and online cooking courses (both free or subscription-based) are available for families(30,31) , although to the best of our knowledge there is no information on the effectiveness of these courses. Online resources may also be beneficial for promoting home cooking, but further studies are needed to evaluate the long-term utility of these tools with families(Reference Clarke, Neffa-Creech and Evans32).
Home cooking interventions could offer additional benefits to families with children beyond interventions that provide only nutritional recommendations. This assumption is based on the fact that it reinforces their ability to make nutritional changes through healthy home-cooked meals, reinforces the knowledge they have acquired and could allow for more lasting behavioural changes. However, previous studies have not provided adequate information about the culinary interventions and/or the professionals involved(Reference Razavi, Sapin and Monlezun22,Reference Robson, Stough and Stark24,Reference Utter and Denny27,Reference Lavelle, Mooney and Coffey28) . In addition, the provision of theoretical background that may support the behavioural change of the participants is missing(Reference Lavelle33). All this information is needed to assess the feasibility of these interventions which usually are more complex in terms of the resources needed and the time and availability of the participants.
In this context, we present the results of the Nutritional and Culinary Habits to Empower Families (n-CHEF) feasibility study. In this study, we evaluated the effect of a hands-on culinary and nutritional intervention involving at least one parent and one child in a kitchen with a dietitian-nutritionist and a chef after over a 9-month period. The main objective was to assess the feasibility, acceptability and efficacy of the culinary and nutritional intervention aimed at increasing the consumption of plant-based foods in the context of the Mediterranean diet and the use of healthy cooking techniques. In addition, we provide a detailed description of the culinary-nutritional intervention conducted in the n-CHEF feasibility study.
Methods
Study design and participants
The n-CHEF feasibility study was carried out at the Department of Preventive Medicine and Public Health of the University of Navarra. The total follow-up was 9 months, and it was divided into two periods: the intervention period (April–June 2021, 3 months) during which parent–child dyads participated in four culinary nutritional workshops (two face-to-face and two online) and the follow-up period (July–December 2021, 6 months).
A total of fifteen dyads of a parent and a child were recruited through an advertisement published in March 2021 in the weekly online newsletter for the employees of the University of Navarra. As the n-CHEF is a feasibility study, sample size calculation was not applied, but we estimated that fifteen parent–child dyads would allow us to find some significant intra-subject differences between baseline and follow-up(Reference Arain, Campbell and Cooper34). The main inclusion criteria were families with an available progenitor and a healthy child aged 10–14 years, living in the same household. The narrow age range for children was chosen in order to design a culinary and nutritional intervention that was as age appropriate as possible in terms of theoretical and practical content. Exclusion criteria were having attended previous cooking courses, food allergies or intolerances incompatible with the culinary nutritional intervention, following a specific dietary pattern, or having a chronic disease including eating disorders.
The trial was registered on ClinicalTrials.gov NCT04986449.
Culinary nutritional intervention
The primary aim of the culinary and nutritional intervention was to promote the consumption of plant-based foods in the context of the Mediterranean diet. The Mediterranean diet is characterised by the exclusive consumption of extra virgin olive oil for all culinary purposes and high consumption of vegetables, fruits, legumes, nuts and whole grains; moderate consumption of fish and very low consumption of red and processed meat, refined grains, sweet desserts, whole-fat dairy products (only consumed in moderation fermented dairy products such as yogurt and cheese) and ultraprocessed foods. The intervention was designed by a multidisciplinary group, including a chef, dietitian-nutritionists and an epidemiologist following the ten experiential drivers of behaviour change in culinary nutrition education identified by Fredericks and cols.(Reference Fredericks, Koch and Liu35). The ten experiential drivers are challenge (trying new foods/flavors and skills), celebration (creating fun, enjoyable and special atmosphere; creating deliciousness from healthy food), collaboration (generating positive group dynamic, a feeling of being part of something bigger), home environment (addressing home dynamics, facilities and access to healthy food; creating solutions and strategies), palate development (tasting a wide range of flavors, create new combinations), peer support (creating an atmosphere of playing level field where new behaviour becomes acceptable), recipe concept (recipe-driven cooking, recipe concepts and ingredients swap), skill building (developing new culinary skills and vocabulary, motivating to share new food strategies with others), skill reinforcement (measuring participants advancing skills) and success (achieving goals, increase participant confidence, competency and sense of accomplishment). The content and activities proposed in the workshops followed at least one of the experiential drivers identified by Fredericks and cols.(Reference Fredericks, Koch and Liu35) to motivate participants towards positive changes in food behaviours. Table 1 lists the experiential drivers applied in each workshop with an example of the content or activity. Figure 1 shows the proposed logic model explaining how behaviour change is expected to occur as a result of the n-CHEF intervention.
Workshops’ description of the n-CHEF intervention
n-CHEF, Nutritional and Culinary Habits to Empower Families.
Logic model of behaviour change of the n-CHEF intervention. N-CHEF, Nutritional and Culinary Habits to Empower Families
During the intervention period, each parent–child dyad attended four workshops and the final n-CHEF meeting (Table 1). The dyads attended the workshops every 4 weeks. Workshops 1 and 2 were conducted face to face for each dyad, and the duration of each was set at 3 h. Workshops 3 and 4 were held online via Zoom in groups of five parent–child dyads and the duration was set at 2 h. We decided to include both face-to-face and online workshops in order to assess the feasibility of both types of intervention. The research team provided multiple option dates to follow-up the workshops to overcome barriers related to unreliable work schedules and children’s schedules. For the final n-CHEF meeting, parent–child dyads were gathered face-to-face on the same day. A chef and a dietitian-nutritionist conducted all the workshops and the final meeting. The research team designed an Excel sheet with the content and the timeline of each workshop (Fig. 2). Before the first workshop, a training session was organised with a dyad (parent–children) not included in the study. In this training session, the chef and the dietitian-nutritionist were able to implement the training plan (nutritional and cooking concepts, recipes, experiments and other activities) devised for the workshop.
Screenshot of the Excel sheet prepared by the researchers with the content and the timeline of each workshop
All workshops were conducted in a kitchen, and they included culinary and nutritional information, both from a theoretical and practical perspective. Parent–child dyads cooked different meals and participated in different activities described in Table 1. In the first workshop, the main objective was to show the nutritional and health properties of plant-based foods in general, and vegetables in particular. After the families experimented with the smells, tastes and colours of different vegetables, they cooked them. The aim of the second workshop was to introduce the families to the concept of sustainable diet where seasonal and local foods should be the foods of choice(Reference Springmann, Wiebe and Mason-D’Croz37). In this workshop, the families cooked vegetables with other less common culinary techniques and learned how to use different spices and aromatic herbs to make their dishes different, avoiding the idea that choosing seasonal and local foods is monotonous. In the third workshop, the aim was to replace the use of refined grains with whole grains(Reference Sievenpiper38), taking into account that whole grains are less accepted by children, and that they are differently cooked than refined grains. Finally, the fourth workshop aimed to introduce the concept of weekly menu planning including the shopping list, the idea of batch cooking and the use of kitchen pantry foods (canned legumes, nuts, seeds) and other frozen home preparations (sofrito, fish broth).
Regarding the economic cost of the culinary nutritional intervention, each family paid for the shopping list provided to them before each workshop except for basic ingredients (salt, whole flour, extra-virgin olive oil and aromatic herbs and spices) and cooking utensils which were provided by the researchers.
Clinical visits
During the study parent–child dyads attended three clinical visits: at baseline (0 months), at the end of the intervention period (3 months) and at the end of the follow-up period (9 months in total) in the facilities of the University of Navarra.
Baseline measurements
At the baseline visit, sociodemographic information and family and medical history were collected from the children. Anthropometric measurements were obtained from both the progenitor and the child, at baseline and at the end of the follow-up period, in light clothing and without shoes. Body weight was measured using the Tanita RD-545 (Tanita Corp), and height was measured to the nearest 1 mm using a portable stadiometer. BMI was calculated as body weight (kg)/height (m)2. For children, the BMI-for-age (BMI/A) z-score was also calculated according to the 2007 WHO growth charts (38). Waist and hip circumference were measured with a flexible tape at the midpoint between the last rib and the edge of the iliac crest and around the maximum circumference of the buttocks, respectively. Finally, children were asked about their physical activity using a previously validated questionnaire for adults(Reference Martínez-González, López-Fontana and Varo39).
Dietary measurements
The children’s dietary habits were analysed at baseline and at the end of the follow-up period using a 147-item semi quantitative FFQ validated for the Spanish pediatric population(Reference Zazpe, Santiago and de la40). Energy and nutrient intakes were derived from Spanish food composition tables(Reference Moreiras, Carbajal and Cabrera41–43).
Adherence to the Mediterranean diet was assessed from children and adults using the validated seventeen-item Mediterranean diet adherence score(Reference Schröder, Zomeño and Martínez-González44). For children, this score was derived from the FFQ but without the question on wine consumption. Mediterranean diet adherence was measured in children, at baseline and after the follow-up period, whereas in adults, it was measured at baseline, after the intervention period and after the follow-up period.
Culinary measurements
Confidence and attitudes about home cooking from progenitors were evaluated at the three in person visits using a self-administered questionnaire adapted from Condrasky and cols.(Reference Condrasky, Williams and Catalano45) and Vrhnovnik(Reference Vrhovnik46). In addition, the Home Cooking Frequency Questionnaire previously validated in adults was administered to progenitors at baseline and at the end of the study(Reference Goni, Gil and de la47).
Feasibility evaluation
Inclusion and retention
We evaluated the recruitment process to identify the potential barriers to family engagement in the project. We also measured the retention rate ((number of participants who completed the trial/total number of participants) × 100) and recorded the reasons for dropout and attrition to identify potential barriers to retention during the 3-month intervention period and the additional 6-month follow-up.
Quality evaluation of the intervention
The research team monitored parent–child dyad attendance, timing and economic costs of each workshop. In addition, after each workshop, a satisfaction questionnaire, developed ad hoc for this study, was sent to parent–child dyads to assess the acceptability of the intervention in terms of quality, durability, content and development of each workshop. This questionnaire included questions using a five-point Likert scale, such as ‘The duration is adequate’, ‘We enjoyed it’, ‘The methodology used has facilitated the active participation of all the family’…; and open-ended questions such as ‘What did you like the best/least?’ and ‘What would you change?’.
In addition, at the end of the intervention, both parents and children self-administered an ad hoc questionnaire aimed to measure the changes in perceptions and attitudes in relation to home cooking. This questionnaire, using a three-point Likert scale, included questions for children such as ‘Now I like vegetables, fruits, whole grains, legumes more than when I started the workshops’, ‘After the study, I help my parents, more cook than before’…; and for parents such as ‘The n-CHEF study helped me to increase the amount of vegetables we cook at home’, ‘The n-CHEF study helped me to increase my awareness of the need to buy local, seasonal products, and to limit waste’…
Outcomes of the intervention
In the feasibility study, we aimed to evaluate changes in dietary and culinary habits in both parents and children. The primary outcome was to measure changes in the adherence to the Mediterranean diet after the intervention in children and parents (seventeen-item Mediterranean diet adherence score(Reference Schröder, Zomeño and Martínez-González44)). The secondary outcomes were perceived benefits of the intervention by children and parents, changes in dietary habits in children after the total 9-month follow-up and changes in culinary habits and cooking confidence and attitudes in parents after the 3 month-intervention period and the additional 6-month maintenance period.
Statistical analysis
Categorical variables were described as absolute numbers and percentages and quantitative variables as mean and sd. The Shapiro–Wilk test was used to test the normal distribution of the quantitative variables. Within-subject changes in dietary and culinary habits were analysed using the Student’s t-test for paired data or the Wilcoxon matched-pairs signed-rank test, depending on the distribution of each variable. Changes in quantitative variables were as mean and 95 % CI. Statistical analyses were performed with STATA software (STATA version 16·0, StataCorp). All P values <0·05 were considered statistically significant.
Results
Enrollment and retention
A total of thirty-two parent–child dyads were interested in participating on the same day that information about the study was disseminated at the University of Navarra (Fig. 3). The first fifteen parent-child dyads that met the inclusion criteria were included in the feasibility study. Three parent–child dyads did not meet the inclusion criteria and the remaining fourteen parent–child dyads were placed on a waiting list. One parent–child dyad refused to participate because the intervention did not fit into with their daily activities prior to the start of the intervention. Therefore, one parent–child dyad from the waiting list was invited to participate in the study. Finally, a total of fifteen parent–child dyads started the intervention. During the study two parent–child dyad were drop-out (1 at clinical visit 2 and 1 at clinical visit 3). Thus, results during the follow-up (including the 3-month intervention period and the additional 6-months) were available only for thirteen parent–child dyads, being the retention rate 86·7 %.
Flow chart of the n-CHEF feasibility study participants (parent–child dyads). N-CHEF, Nutritional and Culinary Habits to Empower Families
Baseline characteristics
Baseline characteristics of the parent–child dyads participating in the feasibility study are shown in Table 2. Eighty percent of the children and 53·3 % of the adults were female. The mean (sd) age was 12·6 (1·3) and 46·5 (5·2) years for children and parents, respectively. A high proportion of the parents in the study had college education (93·3 %), and 66·7 % of the families had three or more children. The mean BMI/A (sd) for children was 0·5 (0·7) z-score, and the BMI mean (sd) for parents was 24·9 (3·7) kg/m2.
Baseline characteristics of the parent–child dyads recruited in the n-CHEF feasibility study
BMI/A, BMI-for-age; MET, metabolic equivalents; NA, not applicable; n-CHEF, Nutritional and Culinary Habits to Empower Families.
* Data are n (%).
Acceptability of the intervention
The fifteen parent–child dyads attended all of the workshops except for one parent–child dyad who did not attend the fourth workshop and two parent–child dyads who did not attend the final meeting. Initially, the duration of each workshop was set at 3 h for the face-to-face workshops (1 and 2) and 2 h for the online workshops (3 and 4). Workshops 1, 2 and 4 lasted the specified time. However, workshop 3 lasted 45 min longer than the established time of two hours. The average cost of the shopping list per workshop was 17€ (five recipes for four people each), whereas the total cost of the materials used in the intervention for the research team was 823€.
Data from the ad hoc satisfaction questionnaire after each workshop were analysed to determine the acceptability of the intervention by the parent–child dyads (Table 3). In general, all workshops were rated highly by most of the dyads in terms of meeting expectations, level of depth of the topics covered, duration, methodology and usefulness of workshops content for everyday life. The workshop that was rated the lowest was the third workshop (on line) in terms of duration, methodology and usefulness of the content. Most parent–child dyads rated workshops 1, 2 and 4 as very good or excellent. However, workshop 3 was rated as good by 44·4 % of the parent–child dyads.
Acceptance of the culinary and nutritional intervention by families
* Thirteen responded of fifteen attended.
† Nine responded of fifteen attended.
‡ Six responded of fourteen attended.
Perceived impact of the intervention
The results of the perceived benefits of the intervention by children and parents are shown in Table 4. After the intervention, most of the children agreed that they had improved their knowledge about cooking (84·6 %) and nutrition (92·3 %). However, 61·5 % of children perceived that their taste for plant foods (vegetables, fruits, legumes and nuts) had not improved as a result of the workshops. In addition, 69·2 % of the children agreed that they do not help their parents cook more often after the intervention. As for the parents, more than 80 % agreed that the intervention helped them to increase the variety of foods (84·6 %), involve their children more in cooking at home (92·3 %), become more aware of nutrition’s impact on health status (92·3 %), become more interested in cooking and gastronomy (92·3 %) and be more conscious on buying local and seasonal products and reducing food waste (84·6 %). However, a substantial proportion of parents were neutral or disagreed that the intervention helped them to cook more at home (38·4 %), reduce the consumption of convenience foods (23·0 %), increase the variety of vegetables cooked at home (30·8 %) and increase the consumption of whole grains (30·8 %).
Perceived impact of the intervention on the children’s and parents’ attitudes towards cooking and nutrition*
* Data from the thirteen families that participated in the four workshops during the 3-month intervention period.
Adherence to the mediterranean diet and changes in dietary and culinary habits
At baseline, the adherence to the Mediterranean dietary pattern, mean (sd), was 5·2 (2·2) for children and 8·1 (1·6) for parents. The Mediterranean diet adherence did no significant changed in children during the total 9-month follow-up (increase, 0·6 (–0·7, 1·9), P = 0·321). On the contrary, parents significantly increased their adherence to the Mediterranean diet between baseline and at the end of the 3-month intervention period (increase, 2·1 (0·7, 3·5), P = 0·005) and between baseline and at the end of total 6-month maintenance period (increase, 2·9 (1·7, 4·2), P < 0·001).
Regarding dietary habits, children significantly increased the consumption of vegetables (P = 0·001), legumes (P < 0·001) and water (P = 0·031) and significantly decreased the consumption of convenience foods (P = 0·007) and snacks (P = 0·042) over the total 9-month study period (Table 5). In addition, a trend towards significance was observed for an increase in the consumption of fruits (P = 0·065) and fish (P = 0·061) and a decrease in the consumption of fats other than olive oil (P = 0·089). No significant differences were observed in the change of consumption of other food groups (dairy products, nuts, cereals and potatoes, meat and processed meat, eggs, sweets, olive oil and sweet and/or carbohydrate beverages).
Changes in children’s dietary habits between baseline and the total 9-month follow-up (n 13)
* Wilcoxon matched-pairs signed-rank test.
Changes in parent’s culinary habits after the 6-month maintenance period are shown in Table 6. In terms of cooking techniques, parents significantly reduced the use of frying (P = 0·036) and stewing (P = 0·047). In terms of food groups, parents decreased the cooking of white meat (P = 0·018), red meat (P = 0·002), vegetables (P = 0·045) and potatoes and tubers (P = 0·024). Parental confidence and attitudes towards cooking at home are shown in Fig. 4 and in online supplementary material, Supplementary Table 1, respectively. After the intervention period, parents significantly increased their confidence in the items ‘knowing when your food is cooked’ (P = 0·014), ‘planning meals for the week’ (P = 0·046) and ‘changing recipes to make them healthier’ (P = 0·015) (Fig. 4(a)). In fact, parents reported significantly higher global confidence scores after the follow-up period (P < 0·001) (Fig. 4(b)). In addition to ‘handling, storing and preparing food safely’ (P = 0·002), ‘cooking grains’ (P = 0·002), ‘cooking vegetables’ (P =< 0·001), ‘cooking meat, fish or poultry’ (P = 0·011), ‘comparing prices’ (P = 0·003) and ‘reading food labels’ (P = 0·026) significant increases in confidence were observed in those aspects that improved in the first period.
Changes in parents’ culinary habits between baseline and the total 9-month follow-up (n 13)
* Wilcoxon matched-pairs signed-rank test.
Changes between baseline and (a) after the intervention (3 months) or (b) the total follow-up period (9 months) in parents’ confidence in cooking at home (n 13)
In terms of attitudes, parents increased their overall attitude towards cooking at home after the intervention period (P = 0·005), although this change did not remain statistically significant after the follow-up period (P = 0·103) (see online supplementary material, Supplementary Table 1). Item by item, parents showed a positive change after the intervention on the items ‘It is not important that I know how to cook’ (P = 0·026) and ‘It is easy to prepare meals’ (P = 0·013) and after the follow-up period on the item ‘It is important to eat the recommended 3 fruits/day’ (P = 0·046).
Discussion
The aim of the present study was to analyse the feasibility, acceptability and preliminary efficacy of a culinary nutritional intervention for parent–child dyads to promote the consumption of plant-based foods in the context of the Mediterranean diet. Overall, the current feasibility study was successful in terms of the acceptability of the culinary nutritional intervention. Significant improvements were also observed in the consumption of some plant-based foods and increased confidence in cooking at home, both in the parents and in the children, during the 3-month intervention period and the additional 6-month follow-up. However, we also found non-significant changes in cooking frequency and use of culinary techniques, suggesting that changes to the intervention are needed before designing a full-scale randomised controlled trial.
In our study, three parent–child dyads dropped out during the follow-up period. This is consistent with previous intervention studies where the dropout rate was around 20–30 %(Reference Manios, Androutsos and Lambrinou48). The reason for dropping out before the start of the intervention or before the end of the clinical visits was lack of time due to other children’s activities or the parents’ work. All the parent–child dyads attended all the workshops, except for one family who was unable to attend one of the online workshops. The high rate of workshop attendance could be partly explained by the fact that the face-to-face workshops were individualised for each family and the research group tried to adapt to the family’s schedule. However, it should be noted that workshops 3 and 4 (online workshops) were conducted in groups of five parent–child dyads, and the quality and satisfaction were rated lower by parents and children. These findings support the idea that in future studies with large samples, where individual family workshops are not possible due to lack of time and funding, face-to-face workshops should be limited to a reduced number of parent–child dyads to allow for personalised intervention. In addition, the organisation of the workshops could be improved to fit around family’s schedules.
In terms of quality, time, content and development, the culinary nutritional intervention was generally acceptable to the dyads, according to the ad hoc satisfaction questionnaire completed after each workshop. However, parents and children found the online workshop three less interesting, and they emphasised that the combination of recipes and activities was more complicated than in other workshops. In this sense, the parent–child dyads reported that this online workshop was difficult to interact with the chef and the dietitian-nutritionist. Although assessing how to deliver the workshops with only two sessions may be limited, according to our results this problem highlights two important methodological considerations. First, workshops should preferably be face-to-face rather than online. Second, in the case of online workshops, the number of parent–child dyads per group should be limited to three or four families per workshop. However, other studies have found that online cooking workshops are well accepted by children(Reference Park, Hwang and Baek49) and adults(Reference Wilson, Bernhart and Carswel50). Future research is therefore needed to clarify whether, when and how face-to-face culinary workshops compare favourably with online workshops for child–parent dyads.
Interestingly, both children and parents reported benefits for themselves and their own families in terms of nutrition and cooking aspects. In this sense, children reported an improvement in their taste for plant-based foods. Involving children in home cooking has been suggested as a strategy to improve vegetable liking(Reference Overcash, Ritter and Mann20,Reference Allirot, da Quinta and Chokupermal51) . For example, the study by Allirot and cols.(Reference Allirot, da Quinta and Chokupermal51) found that involving children in cooking activities could increase their willingness to try new foods, including vegetables. In addition, most adult participants agreed that they increased their consumption of vegetables and whole grains and decreased their consumption of convenience foods. These findings are consistent with previous family intervention studies, which found that cooking interventions were associated with improved dietary habits, including increased consumption of plant-based foods and decreased consumption of processed foods(Reference Razavi, Sapin and Monlezun22,Reference Varagiannis, Magriplis and Risvas23) .
Our study also measured changes in the dietary and culinary habits in children and their parents. Children did not significantly change their adherence to the Mediterranean diet, but they increased their consumption of vegetables and legumes. This result is consistent with previous studies in families analysing the association between home cooking and changes in dietary habits(Reference Razavi, Sapin and Monlezun22,Reference Varagiannis, Magriplis and Risvas23) . Interestingly, in our study, the children reported a reduction in their consumption of convenience foods. This reduction may be due to the increased confidence and attitude towards home cooking reported by parents after the intervention. Indeed, a previous study found a negative association between parents’ cooking skills and their children’s consumption of ultra-processed foods(Reference Martins, Machado and da Louzada52). In contrast to the results for children, parents’ adherence to the Mediterranean diet increased after the intervention. In the same way, Razavi and cols.(Reference Razavi, Sapin and Monlezun22) showed a higher adherence to the Mediterranean diet in families after a 12-h nutrition and cooking course(Reference Trichopoulou, Costacou and Bamia53). As a result, encouraging parents and children to cook at home can be a good family-focused public health approach to promoting long-term healthy eating and cooking habits.
Limited cooking attitudes and cooking confidence have been proposed as barriers to home cooking(Reference Mills, White and Brown6). In this regard, parents reported higher cooking attitudes and cooking confidence after the intervention and the follow-up period, respectively. These findings are consistent with previous evaluations of family cooking programmes(Reference Overcash, Ritter and Mann20,Reference Robson, Stough and Stark24,Reference Fulkerson, Friend and Horning25) . To our knowledge, the current study is the first to assess changes in the frequency of use of an extensive list of culinary techniques and the frequency of cooking by food group. Parents reduced frying, probably one of the most commonly used culinary techniques among families because of its palatability and short cooking time, and they reduced the frequency of cooking white and red meats and potatoes and other tubers. However, contrary to our expectations, we found that parents reduced the number of times per week they cooked vegetables. A previous family cooking intervention to increase vegetable consumption has found increased confidence in vegetable preparation when comparing pre- and post-intervention data(Reference Overcash, Ritter and Mann20). However, this study did not measure the frequency with which families prepared vegetables. Therefore, more research is needed to confirm that cooking interventions increase the frequency with which participants cook vegetables and other food groups.
There are several limitations to this feasibility study. First, since there was no control group, we could not compare the effectiveness of the culinary nutritional intervention with a traditional nutritional intervention. Second, although preliminary analysis showed significant changes in dietary and culinary habits, the trend of results in such a small sample size study should be interpreted with caution. Third, due to resource constraints, we did not measure children’s cooking confidence and skills, and we did not collect an FFQ from parents. However, we measured the adherence to the Mediterranean diet. Fourth, we used self-reported data rather than the use of biomarkers. Nevertheless the questionnaires have been previously validated(Reference Martínez-González, López-Fontana and Varo39,Reference Vrhovnik46,54) . Fifth, the recruitment of families only among the employees of the University of Navarra limits the generalisability of the results to other populations. However, we observed similar proportions of children with low, moderate or high adherence to the Mediterranean diet at baseline to those reported previously in Spanish children(55,56) . Sixth, due to the large disparity in the number of girls and boys recruited (12 v. 3, respectively), it was not possible to present key findings on the feasibility, acceptability and effectiveness of the intervention by sex. Stratifying the randomisation by sex of the children will be important in future studies. Seventh, the n-CHEF intervention focuses on changing dietary behaviour at the individual and family level. However, we recognise that changing dietary habits is a multi-level approach and the impact of the intervention may be limited. Despite these limitations, the study has several strengths. First, the provision of multiple options to follow-up the workshops helped to overcome barriers related to unreliable work schedules and children’s schedules and was crucial to the high retention rate during the follow-up. Second, the culinary nutritional intervention was based on the ten experiential drivers of behaviour change in culinary nutritional interventions identified by Fredericks and cols.(Reference Fredericks, Koch and Liu35) Finally, the study included a post-intervention follow-up period, which allowed us to measure changes in dietary and culinary habits after a total of 9 months.
In conclusion, the n-CHEF feasibility study provides insight into feasibility and patient acceptability of the culinary nutritional intervention. In addition, the hands-on family cooking and nutrition workshops appear to have improved the dietary and culinary habits of the parent–child dyads. These findings will support future randomised control trials to test whether a family culinary and nutritional intervention can improve dietary habits and reduce the burden of childhood obesity and other chronic diseases. In this sense, we have conducted the n-CHEFS a randomised multicentre pilot study to analyse the effect on dietary habits of a culinary nutritional intervention for parent–child dyads compared with a culinary nutritional intervention only for parents or a nutritional intervention for parent–child dyads (ClinicalTrials.gov NCT05280652).
Acknowledgements
The authors thank all of the families involved in the study and the Department of Preventive Medicine and Public Health of the University of Navarra for financial support.
Financial support
This work has been carried out with the Department of Preventive Medicine and Public Health own funds. QvExtra! provided different types of olive oil for the workshops.
Conflict of interest
The authors declare there are no conflicts of interest.
Authorship
L.G. conceptualisation, methodology, investigation and writing – original draft. L.S. conceptualisation, methodology, investigation, writing – review and editing. A.R.-S. conceptualisation, methodology, investigation, writing – review and editing. I.K.-G. investigation, writing – review and editing. N.M.-C. investigation, writing – review and editing. M.R.-C., conceptualisation, methodology, project administration, writing – review and editing.
Ethics of human subject participation
This study was conducted according to the guidelines laid down in the Declaration of Helsinki, and all procedures involving research study participants were approved by the Research Ethics Committee of the University of Navarra (ref. 2021·036). Written informed consent was obtained from both progenitors and children.
Supplementary material
For supplementary material accompanying this paper visit https://doi.org/10.1017/S1368980024001538.
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