Introduction

Childhood obesity is one of the most important problems in public health. In developed countries, it is considered the most prevalent noncontagious disease and nutritional and metabolic disorder [1]. Treatment and prevention of overweight and obesity in children is of fundamental importance because of the negative physical and psychological impact of these health conditions. Excess body fat in childhood overburdens the musculoskeletal and cardiorespiratory systems, causes psychosocial problems, and has been related to a large number of comorbidities [2–6]. In addition, this excess weight in childhood tends to persist into adulthood [7].

In recent years, interventions have been designed to address this epidemic, as evidenced in numerous meta-analyses and review articles [3,5,8–13]. These studies have shown that the interventions with the greatest impact are multidisciplinary, apply strategies to improve physical activity and dietary habits and in some cases also introduce behavioural or motivational strategies, and include family members, usually the children’s parents [5,10]. Nonetheless, very few interventions are successful and adherence is very low [8,11]. In a review of studies analysing interventions based on treating childhood obesity, Ariza et.al. [8] observed that only 35.1% of interventions were effective in reducing body mass index (BMI) or adiposity. In health care settings, despite being where the problem is diagnosed and where many families are generally predisposed to cooperate in addressing this problem [14–16], the percentages of post-intervention improvement drop to 28.8% with respect to BMI or adiposity, 23.5% for changes in physical activity, and 22% in nutrition habits [8]. Therefore, it is of primary important to create efficient interventions for the treatment of childhood obesity. The primary aim of the present study was to evaluate the effectiveness in the primary health care setting of an intensive, family-based, multi-component, behavioural intervention (Nereu Program) compared to the usual counselling intervention, in terms of anthropometric parameters, physical activity and sedentary behaviours, and dietary intake.

Materials and Methods

Randomization

Sixteen healthcare paediatrics units (HPU) agreed to participate in this study. Each HPU was responsible for the recruitment and selection of eligible participants. Randomization was centralized at the Primary Care Research Institute (IDIAP) Jordi Gol site in Lleida. Each cooperating healthcare paediatric unit was provided a sort list (using a computer-generated random number) of their eligible patients who met the inclusion criteria (age and BMIsd), according to the data contained in clinical records. These eligible children had been randomly assigned to one of the study arms, stratified by age group in each HPU (Fig 1).

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Fig 1. Flow Chart of Study Participants.

https://doi.org/10.1371/journal.pone.0144502.g001

Data analysis

Intent-to-treat (ITT) analysis was performed for all recruited participants who completed the basal evaluation (n = 113), independently of whether or not they completed the entire protocol and could be included in further analysis (n = 89). The intent-to-treat analysis was carried out as follows: missing values were replaced by the scale scores of the previous assessment (the last observation carried forward [LOCF]) to assure no increase. The initial analysis evaluated the homogeneity of basal characteristics between the study groups using the two-tailed Student t test for independent samples for quantitative variables and chi-square for nominal variables (Table 1); quantitative parameters were expressed using the number of valid values (n), the mean and standard deviation (sd) and qualitative parameters using relative frequency (n) and percentages (%).

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Table 1. Baseline Measurements of the Nereu Program (NP) and Counselling Group (CG).

https://doi.org/10.1371/journal.pone.0144502.t001

To evaluate the impact on quantitative parameters after 8 months of intervention in both groups, the change from basal values was calculated and significant differences between groups were determined using the Student t test (Analogous test from interaction of two repeated measures: ANOVA) for independent samples (Tables 2 and 3). Absolute effect was estimated using the difference in means between groups for the observed changes and the 95% confidence interval (95%CI) for normal approximation. Standardized effect size (SES) was computed as the mean difference between the intervention and control group divided by the standard deviation of the control measurement. Interpretation effect sizes: Values 0.2–0.5 represent small changes, 0.5–0.8 moderate changes, and >0.8 large changes. Furthermore, percentage increase over baseline was calculated (Δ%).

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Table 2. Pre-post Intervention Differences in Main Outcomes between Nereu Program (NP) and Counselling Group (CG).

https://doi.org/10.1371/journal.pone.0144502.t002

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Table 3. Differences in Outcomes Between Nereu Program (NP) and Counselling Group (CG) by Sex and Age.

https://doi.org/10.1371/journal.pone.0144502.t003

Linear correlation between the number of sessions attended (program adherence) and changes produced in the NP group compared to CG participants was assessed for statistical significance using the Pearson correlation coefficient. Analysis of subgroups by sex and age was used to determine sensitivity and evaluate possible interactions between the effects analysed.

All analyses were carried out using the SPSS statistical packages v. 18 (SPSS Corp). The level of significance was set at p=.05.

Results

The present study included 113 boys and girls and their respective families (Fig 1), randomized into two study groups, 54 in the NP group and 59 in the CG. No significant basal differences were observed between the two groups in age (mean 10.1±1.98 vs. 9.73±1.97years), pubertal stage (Tanner 1 83.3% vs. 82.1%), or sex (50% boys vs. 44.1% girls), respectively (Table 1). Longitudinal analysis of the mean changes observed in the major parameters after completing the intervention is shown in Table 2. Post-intervention change in BMIsd was -0.12 in the NP group and -0.09 in the CG, with no significant difference between the two groups.

At the end of the intervention, the NP group reduced both SED and LPA (-2.52% and -3.76%, respectively) and increased the time dedicated to MVPA (+6.27%), significant differences (p<0.001) compared to the CG, which increased SED and decreased both LPA and MVPA time (+0.97%, -0.37%, and -0.61%, respectively). Notably, the 7.78% increase in MVPA observed in the NP participants represents more than 1 hour/day, bringing the total to 2.85 hours/day of MVPA (Table 2).

With respect to eating habits, after the 8-month intervention the NP participants increased their fruit consumption compared to the CG (+0.62 vs. +0.13 piece/day, p = 0.026), and decreased their intake of processed meats (-0.79 vs. -0.53 servings/day, p = 0.118) and sugar-sweetened juices and soft drinks (-0.26 vs. -0.02 servings/day, p = 0.047), respectively. Both groups reduced their intake of superfluous foods (-0.92 vs. -1.00 servings/day, respectively).

At the beginning of the study, an analysis stratified by sex and age found no differences between any subgroups (Table 3). At the end of the interventions, the differences observed between NP and CG participants in changes in the time dedicated to MVPA and SED were also reflected in all sub-groups except the pre-pubertal age group, where there was no difference between study arms in SED habits (p = 0.183). The post-intervention increase in MVPA was 7.7% for the subgroup of NP boys, and 4.8% for NP girls. Stratified by age, MVPA increased 6.9% for the pre-pubertal NP participants and 6% for the pubertal NP subgroup.

Adherence to the intervention program was similar in both groups, with mean attendance of 51% (46 of 90 sessions) for the NP group and 47.8% for CG participants (n = 4 of 8 sessions). In the NP group, there was a direct correlation between adherence (number of sessions attended) and reduction in anthropometric parameters (BMIsd, r = 0.547, p<0.001; WHtR, r = 0.373, p = 0.014; and WC, r = 0.359, p = 0.018). In all subgroups by sex and age, adherence to program attendance was similar in both study groups.

Discussion

The aim of this study was to evaluate the effectiveness of the Nereu Program as an intensive, family-based, multi-component behavioural intervention in achieving recommended anthropometric parameters and physical activity, sedentary behaviour and dietary intake goals, compared to a standard counselling intervention. After the 8-month intervention, the NP group had improved activity habits (SED, LPA, and MVPA), especially notable in their increase in MVPA to more than 2.5 hours daily. Improvements were also achieved in eating habits, with more than half an additional serving of fruit per day and a one-third decrease in daily servings of sugar-sweetened juices and soft drinks. In both groups, improved anthropometric parameters were observed; however, participants in the NP group who attended the most sessions achieved the greatest reduction in BMIsd, WC, and WHtR.

In the present study, there was high adherence to attending intervention sessions in both groups. This is a very encouraging result, given that the NP intervention consisted of 90 sessions and both interventions covered an 8-month period. Low adherence is typically one of the major limitations of health care interventions [8,34]. In addition, greater adherence in terms of number of sessions attended was correlated with greater anthropometric improvement in the NP group.

In a meta-analysis by Waters et al. of 37 interventions [5], the mean change in BMIsd after the intervention was -0.15 (p = 0.01). The Oslo Adiposity Intervention Study showed a decline of 0.13 in BMIsd [35], similar to that observed in both the NP and CG participants in the present study. These are encouraging results because this represents a beneficial change in paediatric health. Small reductions in BMIsd have been related with metabolic improvements and lower insulin resistance [35,36].

The increase in time spent daily in MVPA and the decrease in SED time after participation in the NP intervention are very encouraging results. These improvements represent an increase in MVPA to more than 2.5 hours daily, surpassing the recommended minimum of 1 hour/day [24]. After the intervention, NP participants spent 3.7 hours/day in SED behaviours, close to the 3.61 hours/day observed in children aged 9–10 years participating in the European Youth Heart Study (EYHS) and less than the 5.59 hours/day recorded by adolescents (14–15 years old) [37], reflecting observation made by other researchers that as children grow up, they become more sedentary and spend less time in MVPA [37–39].

Physical activity is a crucial component of treatment for childhood obesity, due both to the benefits of regular exercise for weight reduction and to the general health improvements that have been reported [40,41]. Comparing the present results with previous studies, 45% of interventions designed to prevent childhood obesity obtain increases in physical activity; in contrast, the rate of effectiveness decreases to 23.5% for treatment interventions [8]. Improvements in active and sedentary habits in the NP group occurred homogeneously across subgroups of sex and age. This is an important outcome because it is known that sports participation decreases with age and that boys tend to be more physically active than girls [38,39]. These findings suggest that the NP intervention was a beneficial program for both boys and girls of all ages (6 to 12 years).

The highlight among the improvements in eating habits was the increased consumption of fruits in the NP group, reaching nearly 3 daily servings; this nutritional intake is considered ideal [42,43]. According to Lock et al. [44], 31% of cardiovascular disease cases are due to low consumption of fruits and vegetables; therefore, healthy eating habits have a significant long-term impact on cardiovascular health [44]. The improved fruit intake in the NP group exceeded the level recorded for Spain in the European Health Survey, in which about 38% of the total population reported eating two or more pieces of fruit daily [43] and 14% of children ate the recommended 3 daily [42,43]. We must also emphasize the large decline in superfluous foods consumed, such as cakes or industrially produced pastries. This is due in great part to the replacement of these products with fruit for dessert. The results also showed that NP participants reduced the consumption of processed meats with high lipid content. This is very encouraging and highly beneficial because eating these products increases cholesterol and changes the population lipid profile, causing a greater long-term risk of arteriosclerosis, angina pectoris, or cerebrovascular accidents [45]. These products are also laden with sodium, a cause of hypertension and increased blood pressure [46]. Another favourable outcome, considering current trends, was the decreased consumption of sugar-sweetened juices and soft drinks. Consumption of these beverages is increasingly prevalent in our setting, representing about 8% of daily calorie intake in the general population’s eating habits [47].In addition, the habit of drinking canned beverages such as colas has been associated with increased bone demineralization because of the high phosphorous content, which can lead to osteoporosis in the long term. Both soft drinks and industrially produced juices contain excessive amounts of simple sugars, which can lead to type II diabetes, overweight, obesity, and other cardiovascular diseases [48].

In the short-term results, the NP intervention proved useful in changing physical activity and sedentary behaviours and improving eating habits, but no significant differences in anthropometric parameters were observed between the study arms. Therefore, we must wait to see if these newly acquired habits are maintained and have long-term anthropometric effects. It will be important to evaluate the mid- and long-term status of these changes.

Limitations

The present study has several limitations that must be considered. Despite high program adherence, the rate of losses and missing values affected the effect size, depending on the parameter, which limited the statistical power to detect differences between groups in the changes observed. Nonetheless, the losses were balanced between the study arms, eliminating the threat of differential bias. The FFQ has certain limitations, even though it was completed jointly by parents and their children to improve accuracy. There are, of course, occasions when parents are unaware of what their children eat outside of the home, such as school lunches or meals eaten at a grandparent’s house. Even with the child’s participation, it is sometimes difficult to reflect food intake with precision. It is important to point out, however, that the FFQ was administered by expert interviewers using food models to improve the reliability of the results and also that this limitation would be equally present in both study arms.

Conclusions

After completing the NP intervention, an intensive, family-based, multi-component, behavioural intervention delivered within a universal primary health care program, significant improvements were observed in activity and eating habits of participating children, compared to the CG intervention. There was an increase in time dedicated to MVPA and a reduction in SED time. Fruit consumption increased more than half a piece per day and daily servings of sugar-sweetened juices and soft drinks decreased by nearly one third of a daily serving. Despite these encouraging short-term results, it remains to be seen if the observed improvements persist at mid-term and long-term follow-up.

Supporting Information

Acknowledgments

We thank the Lleida paediatrics team (Merce Giribet Folch, Julia Jove Naval, M^a Pilar Barranco Moreno, Silvia Ferraz Sopena, Julia Maria Berdascas Viruete, Olga Diez Zaera, Raquel Plasencia Atienza, Gemma Terrer Manrique, Agnes Huguet Feixa, Maria Elena Herrero Crespo, Carlos Gatius Tonda, Daniel Gros Esteban, Maria Luisa Moreno Gonzalez, Silvia Prado Muñoz and Anna Claramunt Cases) for their assistance with the recruitment and counselling group intervention. We also thank all the children and their families for their participation in this study and the 3 secondary schools in Lleida (Marius Torres, Josep Lladanosa and Maria Rubies) who allowed us to use their space to carry out the intervention. We thank the primary care centers (1° de Maig, Balafia, Bordeta, Cappont, Eixample, and Rambla Ferran) and Espai d’Entitats in Lleida for allowing us to use their facilities to carry out measurements, and Amy Rotger Swinbourne for her invaluable participation in data collection and data entry and in coordinating the intervention.

Finally, we want to acknowledge the community health policy of the Institut Català de la Salut (ICS) and the Department of Health of the Catalan government (the Generalitat de Catalunya) for their support and recognition the Nereu Program as a health tool in the prevention and treatment of childhood obesity, and the Nereu Association for directing and taking on the administration of the program.