Parents and Professionals for Healthy Eating–Pedro Ernesto University Hospital (PAPPAS HUPE) is a nonblind randomized clinical trial for the treatment of obesity in children referred by the National Regulatory System to the pediatric nutrition clinic of a university hospital located in the metropolitan region of the city of Rio de Janeiro, Brazil. Obese children aged 7 to 12 years are eligible to participate in the study. The exclusion criteria will be children diagnosed with genetic disorders associated with obesity (congenital leptin deficiency, Down syndrome, Prader-Willi syndrome) or endocrine disorder (hypothyroidism, Cushing syndrome) and patients already under nutritional monitoring or using weight loss medications. These data will be obtained through medical records and/or a questionnaire completed by parents.

The study will employ a parallel design with 2 comparison groups (Figure 1):

The protocol will follow the guidelines of the Consolidated Standards of Reporting Trials [22] and was registered prospectively with the Brazilian Registry of Clinical Trials [RBR-3st5sn].

The project was approved by the Research Ethics Committee of the Pedro Ernesto University Hospital (CAAE: 87593118000005259). The parent or legal guardian of the child will be informed of the need to sign a consent form and assent according to Brazilian Resolution number 466/2012 on research involving human beings from the Health Council of the Ministry of Health to authorize the information provided by the population in a study, emphasizing privacy regarding identification of the content as well as the freedom to withdraw from the research at any time.

The sample size of 48 individuals per group was calculated based on a standard deviation of body mass index (BMI) equal to 3.0 and an expected difference of 1.72 BMI [23] units between the groups, considering a statistical power of 80% and significance level of 5%. We estimate that 5% of participants are likely to drop out of the study during the study follow-up period. To account for this, we have enrolled 101 participants in total.

After the recruitment phase, eligible participants will be randomly assigned to the control or intervention groups. The randomization, which is performed by the dietitian responsible for the trial, will be performed in a block of 10 subjects using a computer-generated sequence of random numbers. The allocation implementation mechanism will be numbered sequentially. Participants will be allocated to each group, and interventions will be promoted by trained nutritionists.

Both groups will participate in 6 monthly standardized educational activities based on the 10 steps of the Food Guide for the Brazilian Population, which will be carried out in the Hospital Toy Library. Recreational materials, audiovisual resources, and pedagogical support necessary to carry out the proposed educational practice, already available, are based on the Activity Notebook–Promotion of Adequate and Healthy Food–Infant Education, developed by the Ministry of Health in partnership with the University of the State of Rio de Janeiro for teachers and health professionals (Table 1) [24]. Activities will be conducted in groups of 10 children. To avoid contamination, activities for the control and intervention groups will be conducted on alternate days.

Educational activities will also be held with parents addressing the same topics as those covered in the children’s workshops. Advice will include changes in family behavior related to food choices and purchases.

After the group activities, individual family consultations for the control and intervention groups will be held. In the control group, the counseling will reinforce lessons learned in educational activities, focusing on food quality. In the intervention group, a food plan will be prescribed for each participant based on nutritional recommendations of the Federal Council of Nutritionists and Brazilian Society of Pediatrics [25,26]. The plan will be reviewed monthly to match energy recommendations and weight change observed in the previous month.

In order to reduce follow-up losses and increase adherence to the study protocol, a telephone call in the week after the appointment will be made with those responsible for the children to evaluate potential difficulties in adhering to the guidelines provided. Those reporting difficulties in participating will be contacted weekly. This intervention description follows the template for the intervention description and replication checklist and guide [27].

Those responsible for data collection will be trained to ensure a high quality of assessment. This training will be conducted with the objective of standardizing the measurement of data and ensuring reliability.

The primary outcome of the study will be variations in BMI. The following secondary outcomes will be investigated: waist-to-height ratio (WHR), waist circumference (WC), neck circumference (NC), blood pressure, body fat percentage (BF%), and biochemical analysis of serum total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, glucose, and insulin resistance. Insulin resistance will be determined at the baseline and endpoint while the other biochemical analyses will be conducted at the baseline, midpoint, and endpoint. The remaining variables will be assessed at every consultation.

Body weight and BF% will be measured using a portable electronic scale (Tanita BC-558). Height will be checked in duplicate using an AlturaExata portable anthropometer (Belo Horizonte). Both measures will be collected with the children barefoot, wearing light clothes, with the arms extended from the side of the body, positioned by the Frankfurt horizontal plane [28,29]. To reduce potential BF% measurement errors, parents and children will be provided with guidelines regarding the intake of liquids, coffee, alcoholic beverages, laxatives, and diuretics prior to the anthropometric evaluation.

To measure WC and NC, a flexible and inelastic metric tape measuring 150 cm and a variation of 0.1 mm will be used. The WC will be measured with the tape placed horizontally at the midpoint between the lower edge of the last rib and the iliac crest [30]. The measurements will be performed with the tape firmly on the skin, without compression of the tissues. The evaluation will be made while standing with the abdomen relaxed and the arms extended out from the body. The WHR will be obtained by the quotient between WC and height, both in centimeters. The NC will be measured at the average neck height.

The classification of nutritional status will be based on BMI values for age, in z-scores, according to sex, based on the new curves proposed by WHO. BMI for age will be calculated using AnthroPlus 2007 software (WHO) [31], and the values obtained will be classified according to the recommended cutoff points for children aged 5 to 19 years: low weight (BMI for age <–2 z-scores), eutrophic (BMI for age ≥–2 and ≤+1 z-scores), overweight (BMI for age >+1 and ≤+2 z-scores), obese (BMI for age >+2 and <+3 z-scores), and severely obese (BMI for age >+3 z-scores). This classification will be performed at the baseline to confirm the inclusion criteria.

Blood pressure will be measured with the HEM-742 blood pressure monitor (Omron Healthcare Inc.), previously validated for use in adolescents [32]. Before taking the measure, it will be verified that the children do not have full bladders, have not taken medication and/or had coffee, and have not eaten up to 30 minutes before the procedure or engaged in physical exercise up to 1 hour before. The measurement will be performed on the right arm, at the level of the heart, supported on a table with a flat surface, with the palm facing up and the elbow slightly flexed. The individual should be seated with feet in contact with the floor or on a flat surface and remain at rest in that position for 5 minutes before the measurement [33]. Two measurements will be performed, with a minimum interval of 2 minutes, and the average of 2 measurements will be calculated. If the difference between the 2 measurements is equal to or greater than 5 mm Hg, a third measure will be taken.

Biochemical analysis of serum total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, and glucose will be determined at the baseline, midpoint, and endpoint. The biochemical analysis will be performed at the hospital’s central laboratory of clinical analyses. After 12 hours of fasting, 10 ml of blood from the left ventricle vein will be collected in vacutainer tubes. The samples will be divided into aliquots, placed in Eppendorf-type tubes, and stored at –80°C until use, when they will be processed and the serum analyzed in a biochemical analyzer (Cobas Integra 400 Plus/Cobas 6000, F Hoffman–La Roche Ltd) with a Roche cassette. Fasting glycemia will be determined by hexokinase, total cholesterol and triglycerides by the colorimetric method, and HDL cholesterol by the homogeneous method (F Hoffman–La Roche Ltd). LDL cholesterol will be calculated by the Friedewald et al [34] equation, recommended by the American Academy of Pediatrics: LDL cholesterol = total cholesterol – HDL cholesterol + triglyceride/5. Insulin will be measured in the hospital’s endocrinology laboratory with the Elecsys 2010 and Modular Analytics E170/Cobas (F Hoffman–La Roche Ltd) by means of a kit that uses the immunoassay method of electrochemiluminescence. The cutoff points used for the evaluation of the serum levels of total cholesterol and fractions will follow the recommendation of the Brazilian Guideline for Dyslipidemias and Prevention of Atherosclerosis [35], and for fasting glycemia the parameter will be that recommended by the American Diabetes Association [36]. Undesirable levels of total cholesterol and LDL cholesterol values equal to or above 170 mg/dL and 110 mg/dL, respectively, and glucose above 100 mg/dL will be considered.

Insulin resistance will be assessed by means of the homeostatic model assessment–insulin resistance (HOMA-IR) index (HOMA-IR = fasting glycemia [mmol/L] × fasting insulinemia [μU/L]/22.5). Values >2.5 will be indicative of insulin resistance.

Data regarding food consumption will be collected at each consultation by means of a 24-hour food recall using netbooks equipped with a multiple-pass method–based computer program for monitoring adolescent food consumption [37].

At baseline, during the individual consultations, a questionnaire covering issues related to socioeconomic, demographic, and behavioral factors will be administered to the adults responsible for the children. Children will be asked about pubertal stage through the Tanner scale [38,39], sedentary activities (video games, television, and computer time), and physical activity using a validated questionnaire including 6 questions about frequency and duration of physical activities [40].

Family socioeconomic status will be evaluated using the Brazilian Economic Classification Criterion [41]. The number of sleeping hours will be ascertained from 3 questions based on 2 large epidemiological studies [42,43]: How many hours on average do you sleep on a normal night? Do you sleep fewer hours per night than you would like? How many hours would you like to sleep to feel like you have recovered? Sleep deprivation will be estimated from the difference between the usual hours of sleep and the hours of sleep the participant feels would facilitate recovery.

The rate of change of primary and secondary outcomes over time will be tested by intention-to-treat analysis based on mixed-effects models, which allow for consideration of incomplete follow-up data and take into account the correlation of repeated measures. Adequacy of the models will be checked graphically through the diagnosis of the residues [44]. The models will be adjusted for sexual maturation. For the analyses, SAS software version 9.4 (SAS Institute Inc) will be used.