Lifestyle patterns during the first two years of life and association with overweight at age 5
Overweight (including obesity) affects more than 390 million children and adolescents worldwide, including 35 million children under the age of 5. Its occurrence as early as the preschool years suggests that some risk factors may operate very early in life. The “first 1,000 days”, from conception to the child’s second birthday, thus represent both a period of vulnerability for future health and a key window of opportunity to prevent overweight and promote health.
Although obesity has a complex etiology, up to 50% of childhood cases may be related to potentially modifiable risk factors within the family environment. These include parental feeding practices (such as not breastfeeding or early complementary feeding) and children’s energy balance-related behaviours, including consumption of energy-dense foods, low physical activity, high screen time, and insufficient sleep.
These practices and behaviours are most often studied in isolation, although they co-occur within “lifestyle patterns” which may have synergistic effects on health. Yet, such patterns have rarely been investigated during the first two years of life, and no study has simultaneously considered parental feeding practices, energy balance-related behaviours, non-screen leisure activities, and sleep quality.
Our study aimed to identify such patterns and assess their associations with overweight at age 5 and the timing of adiposity rebound, as a rebound occurring before age 5 is an established risk factor for overweight later in life.
Within the ELFE (Etude Longitudinale Française depuis l’Enfance) birth cohort, parental feeding practices and energy balance-related behaviours were collected between 2 months and 2 years of age via a parental questionnaire, while anthropometric data were extracted from the child health booklet. Lifestyle patterns were derived using principal component analysis of 18 variables (n = 13,121), and their associations with overweight at age 5 (n = 8,388) and the timing of adiposity rebound (n = 7,845) were assessed using multivariate regression analyses.
Three patterns were identified:
- «Early complementary feeding, discretionary consumption, high screen time»
- «Balanced diet, non-screen leisure activities»
- « Healthy feeding practices, low dairy consumption, suboptimal sleep ».
The first pattern was associated with overweight at age 5 and an earlier adiposity rebound. Associations between the third pattern and anthropometric outcomes were of similar magnitude but did not reach statistical significance. No association was observed for the second pattern.
Considering these practices and behaviours jointly as patterns provides a more comprehensive view, better reflecting real-life situations. Our study shows that these take shape as distinct patterns within the first two years of life, some of which are associated with overweight a few years later, making them relevant targets for prevention and health promotion.
These findings highlight the value of developing early, integrated and multi-behavioural interventions. However, as these practices and behaviours are strongly socially patterned, such interventions cannot be limited to providing information to parents. They must also mobilise structural levers to empower families experiencing social disadvantage and help reduce social inequalities in health from the very beginning of life.
By Mélissa Baietto PhD Student, Sandrine Lioret DR Inserm
