Introducing excess body weight in childhood and adolescence and comparison with body mass index and waist-to-height ratio

Effects of a novel mobile health intervention compared to a multi-component behaviour changing program on body mass index, physical capacities and stress parameters in adolescents with obesity: a randomized controlled trial

Background

Less than 2% of overweight children and adolescents in Switzerland can participate in multi-component behaviour changing interventions (BCI), due to costs and lack of time. Stress often hinders positive health outcomes in youth with obesity. Digital health interventions, with fewer on-site visits, promise health care access in remote regions; however, evidence for their effectiveness is scarce.

Methods

This randomized controlled not blinded trial (1:1) was conducted in a childhood obesity center in Switzerland. Forty-one youth aged 10–18 years with body mass index (BMI) > P.90 with risk factors or co-morbidities or BMI > P.97 were recruited. During 5.5 months, the PathMate2 group (PM) received daily conversational agent counselling via mobile app, combined with standardized counselling (4 on-site visits). Controls (CON) participated in a BCI (7 on-site visits). We compared the outcomes of both groups after 5.5 (T1) and 12 (T2) months. Primary outcome was reduction in BMI-SDS (BMI standard deviation score: BMI adjusted for age and sex). Secondary outcomes were changes in body fat and muscle mass (bioelectrical impedance analysis), waist-to-height ratio, physical capacities (modified Dordel-Koch-Test), blood pressure and pulse. Additionally, we hypothesized that less stressed children would lose more weight. Thus, children performed biofeedback relaxation exercises while stress parameters (plasma cortisol, stress questionnaires) were evaluated.

Results

At intervention start median BMI-SDS of all patients (18 PM, 13 CON) was 2.61 (obesity > + 2SD). BMI-SDS decreased significantly in CON at T1, but not at T2, and did not decrease in PM during the study. Muscle mass, strength and agility improved significantly in both groups at T2; only PM reduced significantly their body fat at T1 and T2. Average daily PM app usage rate was 71.5%. Cortisol serum levels decreased significantly after biofeedback but with no association between stress parameters and BMI-SDS. No side effects were observed.

Conclusions

Equally to BCI, PathMate2 intervention resulted in significant and lasting improvements of physical capacities and body composition, but not in sustained BMI-SDS decrease. This youth-appealing mobile health intervention provides an interesting approach for youth with obesity who have limited access to health care. Biofeedback reduces acute stress and could be an innovative adjunct to usual care.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02781-2.

Association between junk food consumption and cardiometabolic risk factors in a national sample of Iranian children and adolescents population: the CASPIAN-V study

AIMS

Only a few studies have attempted to assess the relationship between junk food consumption and cardiometabolic risk factors in Iranian children and adolescents; therefore, the aim of our study was to determine the association between junk food intake and cardiometabolic risk factors in this population.

STUDY DESIGN

This is a cross-sectional study.

METHODS

A total of 14,400 students were selected from 30 provinces of Iran using multistage, stratified cluster sampling method. Information about student's lifestyle, health behaviors and health status was obtained through a validated questionnaire. Blood pressure was measured and anthropometric indices were calculated. Blood samples were drawn from 3,303 students for biochemical tests. In our study, sugar-sweetened beverages, salty snacks, sweets and fast foods were considered as junk foods.

RESULTS

The mean age of participants was 12.42 ± 2.97 years. Those with metabolic syndrome were more likely to live in urban areas (P = 0.004) and have higher BMI (P < 0.0001). Junk food intake was not related to metabolic syndrome; however, it was associated with increased odds of high BP (OR 1.23, 95% CI 1.09, 1.39), high SBP (OR 1.38, 95% CI 1.09, 1.75), and high DBP (OR 1.18, 95% CI 1.04, 1.35), overweight (OR 1.22, 95% CI 1.08, 1.39) and excess weight (OR 1.14, 95% CI 1.04, 1.25).

CONCLUSIONS

Junk food consumption plays an important role in childhood overweight and is related to high blood pressure in this population.

LEVEL OF EVIDENCE

Level III, case-control analytic studies.

Waist-to-height ratio as a screening tool for obesity and cardiometabolic risk

The waist-to-height ratio (WHtR), calculated by dividing the waist circumference (WC) by height, has recently gained attention as an anthropometric index for central adiposity. It is an easy-to-use and less age-dependent index to identify individuals with increased cardiometabolic risk. A WHtR cutoff of 0.5 can be used in different sex and ethnic groups and is generally accepted as a universal cutoff for central obesity in children (aged ≥6 years) and adults. However, the WHtR has not been validated in preschool children, and the routine use of WHtR in children under age 6 is not recommended. Prospective studies and meta-analysis in adults revealed that the WHtR is equivalent to or slightly better than WC and superior to body mass index (BMI) in predicting higher cardiometabolic risk. In children and adolescents, studies have shown that the WHtR is similar to both BMI and WC in identifying those at an increased cardiometabolic risk. Additional use of WHtR with BMI or WC may be helpful because WHtR considers both height and central obesity. WHtR may be preferred because of its simplicity and because it does not require sex- and age-dependent cutoffs; additionally, the simple message 'keep your WC to less than half your height' may be particularly useful. This review article summarizes recent publications on the usefulness of using WHtR especially when compared to BMI and WC as a screening tool for obesity and related cardiometabolic risks, and recommends the use of WHtR in clinical practice for obesity screening in children and adolescents.