The authors have the following interests: this study was partly funded by Procter & Gamble, Novo Nordisk and Eli Lilly. There are no patents, products in development or marketed products to declare. This does not alter the authors’ adherence to all the PLOS ONE policies on sharing data and materials.
Conceived and designed the experiments: PB MT TT. Performed the experiments: MT PB. Analyzed the data: MT EW TT. Contributed reagents/materials/analysis tools: EW JE TT. Wrote the paper: MT EM TT. Read preliminary manuscript and provided intellectual content: PB MN EW JE.
Family-based behavioural intervention programs (FBIPs) against childhood obesity have shown promising results, but the mediating mechanisms have not been identified. The aim of this study was to examine changes in obese childreńs lifestyle habits during a 2-year FBIP according to their own and parents’ reports, the concordance between these reports and the correlations to change in post-intervention z-BMI.
An observational study of 26 children (8.3–12.0 years) and their parents participating in a 2-year FBIP was performed. Weight and height were measured from baseline to 12 months after the end of the program. Eating habits and physical- and sedentary activity were reported separately by children and parents. Data were analysed with regard to concordance between parents’ and children’s reports and association between the lifestyle reports and change in z-BMI at the study endpoint using descriptive statistics and parametric and non-parametric tests.
According to both children’s and parents’ reports, the level of physical activity among the children had increased after the intervention as well as the agreement between the informants’ reports. According to the children, eating habits had improved, while the parents’ reports showed an improvement only with regard to binge eating. The concordance between children and parents regarding eating habits was slight to fair also after the intervention. No statistically significant associations between changes in lifestyle reports and changes in z-BMI were observed.
Child and parent reports of physical activity were found to converge and display an improvement in a 2-year FBIP, while the reports on eating habits showed a more refractory pattern. Changes in concordance and agreement between children and parents reports did not correlate with weight reduction. Further methods development and studies of the processes during family-based interventions against childhood obesity are warranted.
Obesity among children is a global health problem
An observational single-group design was used for a process evaluation study. The study was planned and reported according to the STROBE guidelines
Sixty-one children and their parents from two municipalities in southeast Sweden were assessed as obese by school nurses and referred to an FBIP in paediatric outpatient care. The inclusion criteria for the FBIP were age between 8– <12 years with obesity and absence of medical diseases
The FBIP was based on a manual for a series of tutor-supervised group sessions for children with obesity and their parents
Eating habits, physical activity and sedentary activity were assessed by structured interviews adapted for children and for parents
Weight and height were measured at baseline, and 3, 12, and 24 months after the start of the intervention, and 12 months after the end of the program (36 months)
For the descriptive computation of data from the child and parental reports, the reports on lifestyle habits were coded using binary variables (yes/no). The question ‘How many minutes/hours do you exercise per day?’ was dichotomized to ‘Physical activity ≥1 hour per day’ (yes/no). The question ‘How many minutes/hours per day do you sit in front of the television, video, or computer?’ was dichotomized to ‘Television, video, computer ≥1 hour per day’ (yes/no).
The Cochrane test was used to analyse if there were any changes between the children’s and the parent’s responses at baseline, and after 3 and 24 months; the McNemar test was used for post hoc analysis. The strength of agreement between the child and parental reports of the child’s habits about eating, physical activity and sedentary activity were analysed as concordance using Cohen’s kappa coefficient (κ). Cohen’s kappa represents the proportion of agreement corrected for chance; perfect agreement if κ = 1
Spearman’s rank correlation analysis was used in the analytic computation of data on changes between the child and parental reports and changes in the primary outcome measure z-BMI at 36 months. For these computations, the original coding of the lifestyle variables was used (yes/no for eating habits, four levels for physical activity and five levels for sedentary activity). In addition, changes in agreement regarding these lifestyle variables during treatment were analysed to see if they were mediators of weight reduction at 36 months compared with baseline. The new change variables for lifestyle and agreement were recorded in three ascending levels of change: worse, unchanged and improved. A positive rho value indicates that a change in level for the worse gives more reduction in z-BMI and level improvement gives less reduction. Negative rho value indicate the opposite, i.e. a level change for the worse indicates less reduction in z-BMI and level improvement indicates more reduction.
SPSS Statistics Version 19 was used for the analysis. Tests were interpreted as statistically significant if
The research protocol for the study was approved by the Regional Ethics Committee for research with human subjects at Faculty of Health Sciences, Linköping University, Sweden (dnr. 03–600) according to the World Medical Association Declaration of Helsinki 2002
All children and parents participating in the intervention provided data at baseline and after 3 and 24 months except for the parents of one child who declined to participate after 24 months. Also, the family that withdrew after 3 months provided data after 24 months.
According to the children’s reports, all three eating habits had improved after 3 months of FBIP and the improvements were maintained after 24 months (
Child response | |||||||||
Baseline | 3 months | 24 months | |||||||
Yes | No | Total | Yes | No | Total | Yes | No | Total | |
Parental response | |||||||||
Yes | 5 | 4 | 9 | 0 | 2 | 2* | 2 | 4 | 6 |
No | 7 | 10 | 17 | 3 | 20 | 23 | 1 | 18 | 19 |
Total | 12 | 14 | 26 | 3* | 22 | 25 | 3* | 22 | 25 |
Kappa | 0.13 | –0.11 | 0.34 | ||||||
Agreement (%) | 58 | 80 | 80 | ||||||
Positive agreement (%) | 48 | 0 | 44 | ||||||
Negative agreement (%) | 65 | 89 | 89 | ||||||
Parental response | |||||||||
Yes | 14 | 2 | 16 | 5 | 1 | 6* | 4 | 8 | 12 |
No | 3 | 7 | 10 | 4 | 16 | 20 | 0 | 13 | 13 |
Total | 17 | 9 | 26 | 9* | 17 | 26 | 4* | 21 | 25 |
Kappa | 0.59 | 0.54 | 0.34 | ||||||
Agreement (%) | 81 | 81 | 68 | ||||||
Positive agreement (%) | 85 | 67 | 50 | ||||||
Negative agreement (%) | 74 | 86 | 79 | ||||||
Parental response | |||||||||
Yes | 8 | 7 | 15 | 0 | 4 | 4* | 1 | 3 | 4* |
No | 5 | 6 | 11 | 2 | 20 | 22 | 2 | 19 | 21 |
Total | 13 | 13 | 26 | 2* | 24 | 26 | 3* | 22 | 25 |
Kappa | 0.08 | –0.11 | 0.17 | ||||||
Agreement (%) | 54 | 77 | 80 | ||||||
Positive agreement (%) | 57 | 0 | 29 | ||||||
Negative agreement (%) | 50 | 87 | 88 |
Statistically significant differences (
The children’s reports indicated that the time they spent on general physical activity (e.g. playing, walking and cycling) had increased after both 3 and 24 months compared with baseline (
Child response | |||||||||
Baseline | 3 months | 24 months | |||||||
Yes | No | Total | Yes | No | Total | Yes | No | Total | |
Parental response | |||||||||
Yes | 5 | 8 | 13 | 22 | 2 | 24* | 22 | 0 | 22 |
No | 6 | 7 | 13 | 1 | 0 | 1 | 1 | 2 | 3 |
Total | 11 | 15 | 26 | 23 |
2 | 25 | 23 |
2 | 25 |
Kappa | –0.08 | –0.06 | 0.78 | ||||||
Agreement (%) | 46 | 88 | 96 | ||||||
Positive agreement (%) | 42 | 94 | 98 | ||||||
Negative agreement (%) | 50 | 0 | 80 |
Statistically significant differences (
At baseline, most of the children and the parents reported that the children spent at least 1 hour per day on sedentary activity, such as watching television and playing video games (
Child response | |||||||||
Baseline | 3 months | 24 months | |||||||
Yes | No | Total | Yes | No | Total | Yes | No | Total | |
Parental response | |||||||||
Yes | 16 | 6 | 22 | 14 | 3 | 17 | 21 | 1 | 22 |
No | 3 | 1 | 4 | 3 | 5 | 8 | 1 | 2 | 3 |
Total | 19 | 7 | 26 | 17 | 8 | 25 | 22 | 3 | 25 |
Kappa | −0.02 | 0.45 | 0.62 | ||||||
Agreement (%) | 65 | 76 | 92 | ||||||
Positive agreement (%) | 78 | 71 | 95 | ||||||
Negative agreement (%) | 18 | 62 | 67 |
Statistically significant differences (
Analysis of the association between changes in the reports of behaviour and change in z-BMI at 36 months showed no statistically significant correlations for children or parents (
Reporting area | Correlation with z-BMI change from 0 to 36 months | |||
Child report | Parent report | |||
Rho ( |
Rho ( |
|||
Feeling hungry most of the time | 0.28 (0.20) | 23 | −0.08 (0.72) | 23 |
Frequent eating | 0.07 (0.76) | 23 | −0.33 (0.14) | 22 |
Binge eating | 0.14 (0.52) | 23 | 0.11 (0.63) | 22 |
Physical activity | 0.29 (0.17) | 23 | −0.35 (0.11) | 22 |
Sedentary activity | –0.06 (0.79) | 23 | 0.01 (0.97) | 22 |
Correlation with z-BMI change from 0 to 36 months | ||
Reporting area | Rho ( |
|
Feeling hungry most of the time | 0.01 (0.98) | 22 |
Frequent eating | –0.15 (0.51) | 22 |
Binge eating | –0.28 (0.21) | 22 |
Physical activity | –0.34 (0.12) | 22 |
Sedentary activity | –0.30 (0.17) | 22 |
We set out to examine the lifestyle habits of obese children during a 2-year FBIP according to their own and parents’ reports, the agreement between these reports, and the correlations to change in z-BMI from baseline to 12 months after the intervention program. The level of physical activity among the children had increased according to the children and the parents, but no decrease in sedentary activity had been accomplished according to both groups of informants. Post-program concordance regarding physical and sedentary activities had improved to perfect. According to the children, their eating habits had improved after the intervention program; the parents’ reports only indicated an improvement with regard to binge eating. Concordance between children and parents regarding eating habits remained between slight to fair after the intervention. We found no statistically significant associations between changes in the lifestyle variables or concordance and changes in z-BMI.
After the intervention, 92% of the children and 88% of the parents reported that the children participated in physical activities ≥1 hour per day. This activity level is in accordance with both the World Health Organization
These observations lead to the more general issue of assessing children’s lifestyle behaviour during FBIPs. In this study, the data on lifestyle behaviors were primarily collected from children and parents for use in the intervention process. The only consistently observed positive change of behaviour associated to the program was regarding physical activity, both according to the informants’ reports and their concordance. One explanation of these findings is the relative overtness of physical activity assessments, where also pedometers and other technical devices rather straight-forwardly can be used for passive surveillance
Previous studies have indicated that cohesion and agreement within families during family therapy is beneficial with regard to achieving treatment goals
This non-randomized study has strengths, but also several evident limitations. The main strengths are the long-term follow-up period and the low non-participation rate. The foremost limitation is the single-group design, having as consequence that it is not possible to distinguish between FBIP effects and normal cognitive and behavioural maturation and development in childhood. The items used for life-style assessments during the treatment process were derived from the manual for tutor-supervised group sessions used for the FBIP
We conclude that the association between child and parental reports of lifestyle habits and factual behaviour and weight outcomes during FBIPs against childhood obesity is complex. Although child and parental reports of physical activity during the intervention were found to converge and display an improvement, the reports on eating habits showed a more divergent pattern. No association between any of these patterns and weight reduction was observed. These findings are also concordant with that conducting conjoint family therapy is not simply a matter of treating young people in the presence of their parents, but that a systemic perspective is essential for understanding how family members are reacting to what goes on
Thanks to Lisa Ring Jacobsson who performed the follow-up interviews with the parents. We also thank statistician Olle Eriksson, PhD for assistance with the kappa analyses.