# Health-behavior intervention increases sedentary breaks in children aged 0–5 years: evidence from the Melbourne Infant Feeding, Activity and Nutrition Trial

## TL;DR

A health intervention for young children unintentionally increased their sedentary breaks, suggesting that how physical activity and sedentary time are accumulated matters for long-term health.

## Contribution

The study introduces a novel focus on how physical activity and sedentary behaviors are accumulated, not just total time, in early childhood obesity prevention.

## Key findings

- The intervention significantly increased the total number of sedentary breaks at 3.5 and 5 years of age.
- No significant effects were observed for other physical activity or sedentary behavior patterns.
- The study highlights the importance of examining accumulation patterns rather than total time alone.

## Abstract

Early childhood physical activity and sedentary behavior influence long-term health, yet evidence on interventions targeting how these behaviors are accumulated – rather than just total time – is limited. This study examined the impact of a parent-focused early childhood obesity prevention intervention on preschoolers’ physical activity and sedentary behavior patterns.

This study is a secondary analysis of data from the Melbourne Infant Feeding, Activity and Nutrition Trial [InFANT] clustered randomized control trial (2008–2013). Physical activity and sedentary behavior data were gathered using ActiGraph™ GT1M accelerometers. To capture insights beyond total time and examine accumulation patterns, the duration and frequency of sedentary bouts [≤100 counts per minute (cpm)], light-intensity physical activity (101–1,680 cpm) bouts, and moderate- to vigorous-intensity physical activity (≥1,681 cpm) bouts, each lasting ≥1 min, as well as the total number of sedentary breaks, were calculated at each time point. The ≥1 min cut-offs for bout durations were defined based on the medians observed in this sample (0.50 min for sedentary, 0.47 min for light-, 0.25 min for moderate- to vigorous-intensity physical activity). Multilevel regression analyses were fitted to examine intervention effects at 19 months (T3), and 3.5 (T4) and 5 (T5) years of age.

In total, 296, 144 and 140 participants had valid accelerometry data and were included in the analytical sample at T3, T4 and T5, respectively. The intervention had a significant and beneficial effect on the total amount of sedentary breaks at 3.5 (β[95%CI] = 10.9[2.98,18.91) and 5 years (β[95%CI] = 7.94[0.03,15.86). The intervention effects on all other outcomes were small and not significant.

Whilst only effects on sedentary breaks were observed, this study suggests that interventions may impact accumulation patterns in children under five.

The Melbourne Infant Feeding, Activity and Nutrition Trial was registered with the International Standard Randomized Controlled Trial Number Register (ISRCTN81847050; 7/11/2007).