Routine Clinic Care Yields Only Modest Weight Gains in Children With Obesity

Childhood obesity has become one of the most pressing chronic health challenges of the century, and a new real-world study from Brazil offers a sobering look at what routine clinical care can—and cannot—achieve against it. If current trends continue, researchers project that by 2035 more than four billion people, roughly half of the global population, will be living with overweight or obesity, and prevalence among children and adolescents is expected to more than double to approximately 383 million worldwide. Against that backdrop, a team at a tertiary public hospital in Campinas set out to answer a deceptively simple question: when children with obesity and their caregivers pass through the standard machinery of a public multidisciplinary outpatient clinic, what actually changes over six months?

The study, conducted within the Brazilian Unified Health System and reported according to STROBE guidelines, followed 111 caregiver–child dyads recruited through consecutive sampling between 2021 and 2023. Children and adolescents aged 8 to 16 years were eligible if they had a prior diagnosis of obesity, defined as a BMI z-score of 2 or higher under World Health Organization criteria, and medical clearance for regular physical activity. Caregivers, the vast majority of whom were mothers—83.8 percent of the sample—had to live in the same household and attend the child’s follow-up visits. Crucially, the researchers implemented no experimental intervention. Every appointment, assessment, and educational encounter followed the clinic’s existing protocol, making this a portrait of obesity care as it is actually delivered in a resource-constrained public system rather than as it might be delivered in an idealized research setting.

The clinical routine began with a mandatory 90-minute educational session delivered by the multidisciplinary team, introducing families to healthy eating, physical activity, hydration, adequate sleep, and screen-time limits based on Brazilian national guidelines. Families then returned within a month for multidisciplinary evaluations involving pediatricians, physical educators, and nutritionists, with follow-up frequency varying from one to three months according to clinical need. At baseline, the children presented with severe obesity: a median BMI z-score of 3.13, a median BMI of about 30.1 kg/m², and a mean age of 12.1 years. Nearly 61 percent were boys. The comorbidity burden was already substantial—21.6 percent of the children had hypertension, alongside notable rates of asthma, hepatic steatosis, anxiety, and insulin resistance—and their caregivers were hardly healthier, with 40.5 percent reporting hypertension and 23.4 percent diabetes, and a median caregiver BMI of 32.0 kg/m².

Using quantile mixed-effects regression adjusted for sex and age, the team tracked anthropometric and behavioral changes at three and six months. The results were modest but statistically meaningful in the short term. Children’s BMI z-score fell by 0.1 at three months, a significant reduction, and body fat percentage declined by 0.4 percentage points over the same period. By six months, however, the momentum faded: the BMI z-score change shrank to a non-significant 0.04, and the improvement in body fat was no longer sustained. In a cohort this severely affected, the researchers caution against dismissing even small shifts, since stabilization or slight decreases in BMI trajectories have been linked to improvements in cardiometabolic risk profiles in other studies. Still, the trajectory of the data itself—an early dip that flattens—tells a story about the limits of low-contact care.

The behavioral picture was even more static. Across the entire follow-up, light physical activity, moderate-to-vigorous physical activity, screen time, and sleep duration showed no significant variation. At baseline, the median child reported four hours of daily screen time and a median of zero minutes of moderate-to-vigorous physical activity per week—figures that barely budged. In the dietary domain, one variable did move: water intake increased modestly and significantly at both assessments, rising by roughly 0.2 liters per day at three months and 0.1 liters at six months. Total caloric intake and sugary beverage consumption remained flat. The researchers interpret this pattern as evidence that standardized guidance at program entry, plus individualized counseling during follow-up, may raise awareness but is rarely sufficient on its own to disrupt well-established behavioral patterns, particularly among socially vulnerable families facing structural and environmental barriers to change.

Perhaps the most striking finding concerned the caregivers. Despite the consistent evidence from intensive family-based intervention programs that child weight reduction often travels with parental weight change, caregiver body composition in this real-world cohort remained remarkably stable across all six months. Weight, waist circumference, BMI, and body fat percentage showed no significant longitudinal variation. Meanwhile, the cross-sectional correlation between caregiver and child BMI stayed moderate and consistent at every time point—0.293 at baseline, 0.274 at three months, and 0.304 at six months—confirming that families share weight profiles. Yet when the researchers examined whether changes moved together, the synchronization dissolved: changes in pediatric BMI z-score were not significantly correlated with changes in caregiver BMI over time, with a Spearman coefficient of just 0.134. In other words, caregivers and children started from similar places, but they did not travel together.

A responder analysis sharpened that insight. Among the 99 dyads with complete follow-up data, 49.5 percent were classified as responders, having achieved a reduction in BMI z-score of at least 0.1 at six months. The single factor distinguishing responders was age: responders were significantly younger, averaging 11.5 years versus 12.5 years for non-responders, a small-to-moderate effect. Baseline caregiver BMI did not differ between the groups. This points to an early window—before obesity becomes deeply entrenched—as the most favorable period for behavioral adaptation, and it suggests that by the time children reach tertiary care with severe, long-standing obesity, the condition is sustained by an interlocking web of behavioral, environmental, and biological mechanisms. Neuroendocrine adaptations and genetic predisposition can elevate the biological set point and blunt responsiveness to lifestyle-based approaches, while emotional eating—using food to cope with stress or distress—may further undermine behavioral guidance.

The authors are careful to frame these findings not as a failure of clinicians but as an expected output of a pragmatic care model. Compared with structured, high-contact family-based behavioral treatments, which have demonstrated stronger results in trials and primary-care implementations, the routine care evaluated here involved variable consultation frequency and few structured behavioral components. Knowledge-transfer strategies, the evidence suggests, rarely produce sustained lifestyle change without ongoing behavioral support, especially in populations contending with food insecurity, financial constraints, and limited access to safe spaces for physical activity. The stability of caregiver BMI throughout follow-up implies that the shared household routines and environmental constraints shaping the child’s behavior persisted largely untouched, potentially capping the effectiveness of recommendations aimed at the child alone.

The study’s limitations are those inherent to real-world observational designs: no comparison group, a short six-month window, a sample sized by clinic flow, losses to follow-up among 12 dyads, and no socioeconomic data. The findings also cannot isolate the effect of the initial educational session from the surrounding multidisciplinary care. Even so, the takeaway is clear and actionable. Routine multidisciplinary care in this public setting may help prevent further deterioration in children with severe obesity, but achieving substantial improvement will demand more: structured behavioral components, increased contact frequency, active engagement of caregivers as agents of change, stronger early detection and prevention in primary care, and consistent implementation of the public policies Brazil already has on paper. As childhood obesity continues to climb, the gap between what clinics can do alone and what families and health systems must do together has rarely been drawn in sharper relief.

Subject of Research: Longitudinal changes in pediatric obesity and caregiver-child BMI associations during routine multidisciplinary outpatient care

Article Title: Family Dynamics and Longitudinal Trends in Pediatric Obesity: A Real‐World Observational Study in a Public Outpatient Clinic

Article References: de Freitas, F., da Paz, M. M., Zago, M. R., Vitolo, M. R., Antônio, M. Â., & Brandão, M. Â. B. (2026). Family Dynamics and Longitudinal Trends in Pediatric Obesity: A Real‐World Observational Study in a Public Outpatient Clinic. Obesity Science & Practice, 12(5), Article e70192. https://doi.org/10.1002/osp4.70192

Image Credits: AI Generated

DOI: 10.1002/osp4.70192

Keywords: pediatric obesity, BMI z-score, family dynamics, caregiver-child dyads, multidisciplinary care, observational study, public health, lifestyle behaviors, adolescent health, Brazil, real-world evidence, weight management