Here is the design of a clinical trial:

Official Title: Efficacy of a Mindful Eating Program to Reduce Emotional Eating in Patients Suffering From Overweight or Obesity in Primary Care Settings: a Cluster Randomized Controlled Clinical Trial Protocol

Included conditions:
- Overweight and Obesity

Study Armgroups:
- {'label': 'Experimental', 'type': 'EXPERIMENTAL', 'description': 'Mindful Eating program is apply face to face 7 sessions of 120 minutes/session. ME is apply in groups of 10-12 people in traditional format. Written material and sound recordings will be offered as support elements. The estimated duration of the face to face program is two months.', 'interventionNames': ['Behavioral: Mindful Eating']}
- {'label': 'Control', 'type': 'NO_INTERVENTION', 'description': 'Treatment As Usual (TAU) in Primary Care (PC) is any kind of treatment administered by the GP to the patient with overweight and obesity. According to nutritional status, overweight or obesity, as well as the presence of co-morbidity, different actions can comprise the treatment offered at a PC level. For individuals presenting with overweight (BMI 25-29.9 kg/m2) but with no co-morbidities, PC teams organise care plans to enable them to achieve a normal BMI range (BMI 18.5-24.9 kg/m2). In case of suicide risk, severe social dysfunction or worsening of symptoms, it is recommended that patients are referred to mental health facilities.'}

Interventions:
- {'type': 'BEHAVIORAL', 'name': 'Mindful Eating', 'description': 'The ME group will be composed by 7 weekly group sessions with a minimum duration of two hours, mixing theoretical contents with practices. Sessions will always be the same day of the week, except for bank holidays or eventualities, and will be conducted by a psychologist specially trained and certified in ME with experience in leading mindfulness groups. Group sizes will range between 10 and 12 participants. At the end of each session, participants will receive theoretical contents and homework activities to be practiced along the week.', 'armGroupLabels': ['Experimental']}

Primary Outcomes:
- {'measure': 'The Dutch Eating Behavior Questionnaire', 'description': 'It was designed to measure eating styles that may attenuate or contribute to the development of overweight. It comprises three scales that measure emotional, external and restrained eating. The Spanish version of the DEBQ has 33 items, 13 of them referred to the emotional eating scale (e.g., "Desire to eat when irritated"), and 10 items referring to the external (e.g., "Eating when you feel lonely") and restrictive (e.g., "Difficult to resist delicious food") scales, respectively. The items can be rated on a five-point likert scale with 1 indicating "never" and 5 indicating "very often".', 'timeFrame': 'Baseline in experimental and control groups.'}
- {'measure': 'The Dutch Eating Behavior Questionnaire', 'description': 'It was designed to measure eating styles that may attenuate or contribute to the development of overweight. It comprises three scales that measure emotional, external and restrained eating. The Spanish version of the DEBQ has 33 items, 13 of them referred to the emotional eating scale (e.g., "Desire to eat when irritated"), and 10 items referring to the external (e.g., "Eating when you feel lonely") and restrictive (e.g., "Difficult to resist delicious food") scales, respectively. The items can be rated on a five-point likert scale with 1 indicating "never" and 5 indicating "very often".', 'timeFrame': 'Post-treatment 8 weeks from baseline in experimental and control groups'}
- {'measure': 'The Dutch Eating Behavior Questionnaire', 'description': 'It was designed to measure eating styles that may attenuate or contribute to the development of overweight. It comprises three scales that measure emotional, external and restrained eating. The Spanish version of the DEBQ has 33 items, 13 of them referred to the emotional eating scale (e.g., "Desire to eat when irritated"), and 10 items referring to the external (e.g., "Eating when you feel lonely") and restrictive (e.g., "Difficult to resist delicious food") scales, respectively. The items can be rated on a five-point likert scale with 1 indicating "never" and 5 indicating "very often".', 'timeFrame': 'twelve-months follow-up in experimental and control groups'}

Please estimate the sample size based on the assumption: 
The assumptions include a 5% significance level, 80% power, and a 20% dropout rate at 1-year follow-up. The intracluster correlation coefficient (ICC) is assumed to be 0.03.
Sample size
        The sample size estimation has been based on the main comparison, which contemplates the possible differences between the âME +TAUâ and âTAU aloneâ groups of patients. Based on previous research,72 we assume that âME +TAUâ would be able to present high effects compared with âTAU aloneâ on EE at post test. To operationalise this, we consider a standardised difference between arms on the referred main outcome of 0.80.72 To detect this difference between the groups, assuming a common SD, a 5% significance level and a statistical power of 80% using a 1:1 ratio, we need 25 subjects in each group. However, these numbers correspond to the sample size needed under individual randomisation, which is the absolute upper bound for cluster sizeâclusters are randomised and thus we need to allow for the correlation between the EE outcomes of participants from the same cluster.73 To determine the minimum number of clusters needed, we used the formula ân * ICCâ, where n is the sample size for each arm under individual randomisation and ICC is the intracluster correlation coefficient that quantifies the amount of within-cluster correlation for the outcome of interest, assuming a typical fairly value in CRTs of ICC=0.03,74 with a result of approximately one cluster in each arm. Because the number of clusters in the trial is limited by the number of PC settings available to implement the ME programme, we increased the number of clusters to one more than the minimum, supposing that the cluster size would be at most ân/1â. Thus, we fixed the number of clusters per arm to 2 in order to determine the required cluster size.75 In order to maintain the same absolute difference and significance level described above to achieve 80% power with 2 clusters in each arm, we needed a cluster size of 16 participants. In addition, by fixing the cluster size at 16 participants in the same conditions, we obtained the need of 2 clusters per arm, equating to a total sample size of 64 subjects under the condition of equal cluster sizes. Finally, we inflated the numbers to reach a total sample size of 76 patients (38 per arm), considering a drop-out rate of approximately 20% at 1-year follow-up.76 This can be considered an efficient design based on the rule that cluster size should not exceed the number estimated in each arm under individual randomisation.73 This number also enlarges the sample size under individual randomisation in a measure that includes the design effect âDEFF=1 + (m â 1) * ICCââwhere m is the average number of patients per clusterâwith a value of DEFF=1.45, and thus demanding an increase with regard to individual randomisation of around 45%.57