The inclusion criteria in the set-up of two groups of 8 to 15 participants, included: Body Mass Index (BMI: kg/m²) between 30 and 39.99: kg/m²; age between 30 and 60 years, both genders; availability to attend meetings. The initial sample consisted of 28 participants, of which one was excluded because he had previously participated in clinical studies; one was also excluded because he had already undergone bariatric surgery and three were excluded because the BMI did not correspond to the research inclusion criteria. Twenty-three adults were considered eligible and all interviews and assessments took place face-to-face. In the initial interview, the weight and height of the participants were measured to confirm the inclusion criteria. Each participant was interviewed individually based on a semi-structured script. Participants considered eligible were divided, for convenience, into two groups according to their time availability to participate in the intervention, and had no prior knowledge of the allocation.

Both groups participated in the Cognitive-Behavioral Therapy in an interdisciplinary group, with the participation of a nutritionist (session 3) and a physical education professional (session 5). In the first and last sessions, an anthropometric assessment and reapplication of the instruments were performed. The BMI was calculated by dividing weight by height squared and neck, waist and hip circumferences were measured using a measuring tape (Moraes, Pisani et al., 2013). The R Software was used to perform the statistical analysis (R Core Team, 2020). In assessing the data normality, the Shapiro-Wilk test was used. To verify whether there was a group effect and the assessment of anthropometric and instrumental measurements, the ANOVA model with repeated measures and the Bonferroni POST HOC method of multiple comparisons were used. To assess the Effect Size (ES), in relation to the baseline and final assessments of both groups, the Hedges’ g estimate was calculated, which provides a bias correction for Cohen’s d for a small sample (Cohen, 1988).

The analysis of verbal and written reports was developed based on the content analysis proposed by Minayo (2012). Understanding constitutes the central element in the qualitative analysis, which seeks to consider the uniqueness, experiences and life story of the individual that occur within the scope of collective history and that are contextualized and involved by the culture of the group in which they are inserted (Minayo, 2012).

The study was approved by the Ethics and Research Committee of UNIFESP (CAAE: 08314219.0.0000.5505, under appraisal nº 3.316.383). Participation in the study was formalized by the signing of the Free and Informed Consent Form by all volunteers. The study is registered in the Brazilian Registry of Clinical Trials RBR-554pws and the universal trial number of this study is U1111-1254-3992.

As shown in Table 2, the statistical analysis showed that CBGT produced a reduction in body mass (ΔCBGT = -4.73 ± 4.22 and ΔCBGT+Deck = -1.45 ± 2.76, p = 0.003), BMI (ΔCBGT = -1.77 ± 1.57 and ΔCBGT+Deck = -0.83 ± 1.39, p = 0.002), anthropometric measures of neck circumference (ΔCBGT = -1.56 ± 1.88 and ΔCBGT+Deck = - 0.63 ± 0.83, p = 0.006), the result of the Binge Eating Scale (BES) (ΔCBGT = -9.88 ± 7.43 and ΔCBGT+Deck = -7.50 ± 4.57, p < 0.001); improvement of quality of life indicators in the physical domains (ΔCBGT = 0.27 ± 0.62 and ΔCBGT+Deck = 0.39 ± 0.47, p = 0.02), social relationships (ΔCBGT = 0.25 ± 0.43 and ΔCBGT+Deck = 0.42 ± 0.59, p = 0.013), environment (ΔCBGT = 0.27 ± 0.56 and ΔCBGT+Deck = 0.37 ± 0.27, p < 0.001) and Scale of Self-efficacy to regulate Eating Habits (ΔCBGT = 10.50 ± 16.30 and ΔCBGT+Deck = 15.97 ± 18.48, p = 0.04) regardless of the group. There was a reduction in the measurement of hip circumference only for the CBT group (ΔCBGT = -4.63 ± 4.02, p = 0.050) and an increase in the quality of life indicator in the Psychological Domain only for the CBGT+Deck group (ΔCBGT+Deck of Cards = 0.62 ± 0.29, p = 0.019 Effect size 1.91 large) (Neter et al., 1996).

After skimming the text, followed by the systematic review of verbal and written reports, the units of analysis were inferred. Subsequently, the data were grouped and categorized (Minayo, 2012). Three categories emerged: reflections on changing behaviors; difficulties to change behaviors; behavior changes.

In the category reflections on changing behaviors, the reports showed the participants’ awareness and motivation about the need to change attitudes in connection with food choices and physical activity practice:

I love to find an excuse for my slips. (… ). When I did all the exaggeration of the weekend, my criticism was: “wow, aren’t you on a promise? Why did you abuse? Why did you lick the “brigadeiro” pan? ( … ). (P.4, session 4- CBGT)

By reading those cards I was able to review how I am leading my life. I realized that I need to radically change my lifestyle. (P.18, blue card – CBGT+Deck)

The cards are helping me a lot, especially when I randomly pick some cards from the deck. They were my company during that week. (P.18, green and purple card – CBGT+Deck)

I’m already questioning myself before I eat. It is a great help, because before I did not question myself about it. (P.21, green-purple card – CBGT+Deck)

In the category ‘difficulties to change behaviors’, obstacles to change were perceived in everyday life, involving issues related to health, daily stresses and family and cultural characteristics, as can be seen in the following reports:

My mother doesn’t like to make salad, ( ... ). I had to summon myself, the food is for you to eat and you will have to arrive ten minutes earlier and prepare your own salad. (P.5, session 7- CBGT)

When I was eating the fittest cake, I was paying attention to what I was eating. On those days I was so spaced out that I wasn’t paying attention to what I was doing, when I realized I had already finished eating. (P.17, session 4- CBGT+Deck).

In the ‘behavior changes’ category, the participants demonstrated more assertiveness in relationships, in the ability to refuse food offered and facing the possibility of displeasing other people from the negative:

But that’s where our thoughts are worth. Resisting is our psychology. If it was a while ago I would have already taken a fork, try it. I didn’t do that because I stopped to think that I wasn’t hungry (P.2, session 6- CBGT).

This week I stopped to eat because of one of the cards (Avoid distractions when eating) and I put it in my fridge (P.21, session 4- CBGT+Deck).

There’s a card that I try to keep always visible, which is: ‘your body doesn’t know what a weekend is’, because then you take Friday, Saturday and Sunday. ( ... ) I’m learning to keep the balance! (P.17, session 9- CBGT+Deck).

Obesity is a chronic disease, involving multiple determinants (psychological, social, environmental, genetic), which has an economic impact and an impact on the public health system. From this perspective, the literature has pointed out interventions of an interdisciplinary nature as the most effective ways to manage obesity (Bevilaqua et al., 2016; Evangelista et al., 2019; Fernández-Ruiz et al., 2020; Leite et al., 2017; Moraes, Padovani et al., 2021). The non-drug interdisciplinary intervention constitutes important evidence for the treatment and prevention of overweight, obesity and their comorbidities, improving the quality of life and reducing the risk of mortality in this population.

The positive outcomes of multi- or interdisciplinary treatments are related to patient adherence and engagement in lifestyle changes that involve physical activity and a balanced diet (Mendes et al., 2016). It is recognized that the high costs of interdisciplinary treatments require more accessible alternatives for the treatment of the disease. From this perspective, this study seeks to fill that gap as it presents a proposal for a brief intervention using a support tool that is easy to access and manage. Publications suggest carrying out quanti-quali studies in patients with obesity from the perspective of integrating variables and thus improving understanding of the complexity of their disease (Evangelista et al., 2019). However, few studies were published addressing a mixed methodology, which makes it difficult to discuss their findings (Ulian et al., 2018).

After the statistical analyses of the present study, it was observed that the perception of quality of life in the psychological domain improved significantly for the CBGT+Deck group at the end of the intervention. Questions related to this domain address negative and positive feelings, body image, self-esteem and satisfaction with appearance. The impact of obesity on body image, sense of well-being, sexuality, experience of isolation and prejudice, as well as physical impairment caused by the disease are discussed (Leite et al., 2017; Phelan et al., 2020; Ulian et al., 2018). In this connection, improvement in the participants’ perception of quality of life in the psychological domain who used the Healthy Lifestyle Deck of cards was considered a relevant finding of this study.

As a tool management strategy, participants in the CBGT+Deck group were instructed to place the Lifestyle Deck of cards in visible places so that their attention would be directed to its content, as well as the use of coping cards in clinical practice. Although no publications were found that reported clinical studies using decks of cards as a tool, recent studies have shown that modifying the attentional bias is a strategy used in cognitive training of overweight and obese patients (Dalle Grave et al., 2020; Moraes, Padovani et al., 2021).

Cognitive training can be administered via computer or portable device, considered more practical than traditional behavior change treatment. However, it is important to highlight that it is essential that the intervention is intermediated by a health professional (Jones et al., 2018). As well as the use of deck of cards, studies show that in the treatment of overweight or obese individuals techniques are employed that use specific stimuli to draw attention, such as visual tasks exhibited in places associated with food. Jones et al. (2018) point out that training with specific inhibitory control cues is also used, such as associating images of food with the word “stop” or with the red light of a traffic signal. Improving the capacity of reflexive processes is considered fundamental in the treatment of obesity because it involves the development of inhibitory control strategies, which corresponds to the ability to stop, modify or delay the response that is not appropriate, which is considered the key in the self-control process. Strategies are also indicated to maintain the weight loss goal, especially when the individual is faced with a food of great enhancing value for him (Jones et al., 2018).

Another randomized clinical study showed that performing cognitive training improved brain executive functions such as attention, cognitive flexibility, decision-making and task planning, aspects that favor weight loss and better control of impulsivity (Muñoz Galindo et al., 2019).

Because it is an easy-to-handle physical resource, the present study demonstrated that the Healthy Lifestyle Deck of cards can be applied both in group and in individual interventions. Another aspect worth mentioning is that the material can continue to be used by the individual after the end of the intervention, helping rescuing the work aspects of the sessions. As can be seen, the proposed deck is presented as a therapeutic resource in the process of self-monitoring and maintenance of the new cognitive and behavioral pattern.

Despite presenting limitations regarding the statistical analysis because a sample calculation was not performed, a decrease in body mass and BMI was observed, with a larger effect size in the CBGT. This data can be explained due to the fact that the CBT group had a greater reduction in body mass compared to the CBGT+Deck group (ΔCBGT = -4.73 ± 4.22 and ΔCBGT+Deck= -1.45 ± 2.76, p = 0.003). This enhances the importance of educational health actions in changing behavior among overweight and obese individuals.

Data referring to binge eating, perception of physical domains, social relationships and environment of quality of life and self-efficacy to regulate eating habits showed that the effect size was greater in the CBGT+Deck group. The reduction in hip measurement was significant only for the CBGT.

Regarding the classification of the severity of binge eating, it is noteworthy that in the CBT group in the initial assessment, one participant had severe compulsion symptoms, four had moderate compulsion and three had no compulsion symptoms. At the end of the intervention, one had moderate compulsion and seven had no compulsion symptoms, demonstrating a significant reduction. In the CBGT+Deck of cards group, in the initial assessment, one participant had severe compulsion, three moderate compulsion, and four did not show compulsion. At the end of the intervention, the eight participants did not show symptoms of compulsion.

It is known that CBT is traditionally recognized as the best treatment for binge eating and the most used intervention in the treatment of obesity (Castelnuovo et al., 2017; Dalle Grave et al., 2020; Moraes, Padovani et al., 2021). It is considered as the first line of psychological approaches in the treatment of overweight and obesity, especially in the long term perspective. Maintaining therapeutic gains is one of the main challenges for health professionals and researchers who study obesity (Castelnuovo et al., 2017; Moraes, Padovani et al., 2021).

The literature in the area demonstrates a clear relationship between lifestyle and obesity (Fernandez-Ruiz et al., 2020). Interventions focused on changing lifestyle that use specific weight control strategies were associated with improved quality of life, especially in individuals who practiced physical activity and used more psychological coping strategies (Phelan et al., 2020). Recent studies have shown that personal strengths are required in coping with chronic diseases, such as a sense of self-efficacy and persistence, as well as having support from family, friends, peers and health care, and among self-management strategies, being active, knowing how to plan and prioritize, reduce stress, have goals, seek knowledge and help (Kristjansdottir et al., 2018). Thus, the improvement in self-efficacy to regulate the eating habits of both groups can also be pointed out as another relevant finding of this study.

With regard to mental health, the literature also demonstrates that obesity and depression have a two-way association. Individuals with depression are more likely to gain weight due to food choices high in fat, sugar, and sodium and reduced physical activity. Anxiety also plays an important role in eating behavior, as it can cause relief and avoidance of negative emotions. According to a recent study by Moraes, Padovani, et al. (2021), symptoms of depression and anxiety are the result of cognitive distortions. It is believed that interdisciplinary therapy can favor flexibility and adaptation of cognitive patterns, mitigating psychological suffering and producing effective behavioral changes (Moraes, Cipullo et al., 2019).

The psychological effects of obesity involve body dissatisfaction, low self-esteem and the presence of symptoms associated with depression (Lores et al., 2020). Although in the CBT group one participant had a diagnosis of anxiety disorder and one of depression and in the CBGT+Deck group two participants had a diagnosis of anxiety disorder, the intervention did not provide significant changes in the indicators of depression, anxiety and stress of the participants of both groups. Considering that self-efficacy for practicing physical activity was the variable that suffered the least impact from the intervention in both groups, it can be inferred that interventions that provide the practice of supervised physical activity in a group can favor participants’ adherence and regularity (Moraes, Cipullo et al., 2019; Moraes, Padovani et al., 2021; Poli et al., 2017).

Regarding the strategies used during the intervention, the food diary was used as a task aimed at self-monitoring the food consumed throughout the week, corroborating the literature (Phelan et al., 2020). The study that used the immediate recording of the consumption of highly palatable foods in everyday situations found that people who habitually consume highly palatable foods are more likely to use this strategy to deal with stress (Ulian et al., 2018).

The participants’ verbal and written reports complemented and expanded the understanding of the quantitative results. Bonding between the participants and the professional team was considered essential for the development of a therapeutic environment favorable to change and overcoming the difficulties encountered. It was observed that the intervention created favorable conditions for participants’ cognitive and behavioral changes in both groups which demonstrated increased awareness and motivation to change their lifestyle necessary in the treatment of obesity.

The experience of sharing lived situations, difficulties and achievements contributed to the change in the participants’ way of thinking and acting in relation to food and physical activity. The difficulties reported by the participants and the perception of the risk of being overweight can cause to health were also associated with changes in behavior. Thus, cognitive and behavioral changes could be verified in verbal and written reports. Participants in both groups talked about aspects they would like to change in themselves (category reflections on changing behaviors), mentioned identifying problems and difficulties with changing lifestyle (category difficulties changing behaviors) and expressed about concrete changes in relation to eating habits and practice of physical activity (behavior change category).

Thus, it can be stated that the improvements in the quantitative parameters are explained by the qualitative analysis. Changes in eating behavior and sedentary behavior can be exemplified in the reports of participants who mentioned:

Just yesterday I walked, there are 5 floors, I walk up. If I can go up and down walking I will ( ... ). I think after the group I’m more concerned. When I go to the market I remember the nutritionist saying, this is not an ultra-processed food. (P.7, session 7- CBGT)

And on using the Deck as support for change:

This week I stopped to eat because of one of the cards (“Avoid distractions when eating”) and I posted it on my fridge. (P.21, session 4- CBGT+Deck)

The scientific literature demonstrates that the success of the long-term treatment of obesity is related to maintaining a healthier lifestyle, as well as engaging in physical activity programs that promote increased energy expenditure, eat better quality of food and use longer time dedicated to exercises. We highlight the choice of less processed foods, consuming more fruits and vegetables, maintaining energy homeostasis, seeking a negative energy balance. Phelan et al. (2020) reinforce that in those who practiced strategies to maintain body weight, an increase in the perception of quality of life was also observed, especially among those who developed the habit of exercising and who used cognitive and behavioral strategies learned during interventions for coping of everyday problem situations. The improvement in quality of life can also serve as a motivation for maintaining weight loss and maintaining it in the long term (Phelan et al., 2020).

This study demonstrated that supportive therapeutic resources such as the Healthy Lifestyle Deck of cards can stimulate self-monitoring, improve the perception of quality of life and serve as support for cognitive and behavioral changes in individuals with obesity. The results indicate that the cards can be used as homework during cognitive-behavioral therapy, helping to improve body composition and providing long-term therapeutic gains, since they serve as “reminders” of how to think and act functionally after the end of the intervention. Aiming to deepen the effects found, it is suggested to carry out interventions that use coping cards with a larger number of participants. Future interventions envisage the possibility of evaluating how the deck as a coping strategy can be a validated instrument in everyday life, identifying the time of use and effectiveness in changing the behavior of those who use it in adopting a healthy lifestyle.