The association between early life stress and obesity

19 September 2017
Crying child

A new report outlines the evidence for the association between stress in early life and an increased risk of obesity or being overweight as an adult.

The Healthy Eating Research report, Stress in Early Life and Childhood Obesity Risk, details significant research into the impact chronic early stress can have both physiologically and behaviourally which result in a greater risk of obesity.

The report outlines a range of studies highlighting the impact stress can have on both pathways.  They say early life stress can:

  • Disrupt the function of the hypothalamic-pituitary-adrenal (HPA) axis which can potentially increase the risk of obesity.
  • Affect the sympathetic nervous system (SNS) leading to the release of stress hormones which could influence eating behaviours.
  • Disrupt hormones that regulate appetite, metabolism and fat storage.
  • Negatively impact on brain development, particularly the areas that govern executive function and reward systems.
  • Lead to disrupted eating, physical activity and sleep patterns.

The report details sources of early life stress including adverse childhood experiences such as physical, sexual or emotional abuse, domestic violence, mental illness in a household member; poverty; food insecurity; and an unpredictable parent-child relationship.   

It then goes on to detail the evidence for the links between early life stress and the changes in biological and behavioural pathways which can lead to an increased risk for obesity.

These include:

  • A longitudinal study which found that children exposed to early life stress had lower self-regulatory abilities and higher BMI gains.
  • Studies which show that better executive function skills are positively associated with fruit and vegetable intake and negatively associated with eating high-calorie snacks.
  • A review which found that obesity was consistently associated with lower executive function in children.
  • Studies which show that early life stress can lead to diminished reward-related brain activity which can lead an individual to seek out food to temporarily boost dopamine level and stimulate their reward system.
  • Studies which show that excess cortisol due to chronic stress can lead to obesity and an increase in appetite or over-eating.
  • Studies which show that if a mother is stressed during pregnancy, it can affect length of gestation, birth weight and the likelihood her child will be overweight,
  • Evidence which shows that living in a chaotic home environment increased children’s risk for obesogenic eating behaviours.
  • Experiments which show that children exposed to acute stress demonstrate lower levels of physical activity and increased levels of sedentary activity.
  • Studies which show that chaotic home environments impact on children’s sleep which can lead to a dysfunction in the hormones that control appetite and lead to obesity.

The authors conclude that early life stress is associated with childhood and later life obesity.

They say stressful early life events can set of a cascade that has “far-reaching negative neurobiological, cognitive and social-emotional, behavioural and physical health effects.”

They conclude: “Understanding the multiple sources of chronic stress that children can experience and how they can affect biological and behavioural pathways to weight and health is a critical first step toward developing effective prevention and intervention programs and policies that modify these pathways to eliminate risk for young children and change health trajectories for already overweight or obese pre-schoolers.”

You can read the full report Stress in Early Life and Childhood Obesity Risk here.