Can Toxic Stress from Childhood Lead to Adult Obesity?

Jonathan Vellinga, MD

Our experiences in childhood shape our decisions, our personalities, our relationships, and… our bodies? While the first three aspects of our past seem clearly to influence our present, the correlation between childhood experiences and adulthood weight gain might not be as obvious. Nonetheless, these experiences in early life can affect factors such as psychological health, cortisol regulation, gut microbiome, sleep quality, and inflammation, all of which may lead to weight gain years later.

Can Toxic Stress from Childhood Lead to Adult Obesity?

Toxic Stress from Adverse Childhood Experiences

The most negative adverse childhood experiences (ACEs) include all forms of abuse, neglect, parental mental illness and substance use, death, divorce, incarceration, and violence, according to the CDC (1). These eight factors all lead to toxic stress, though less extreme experiences such as moving frequently, living in an under-resourced community, or food insecurity can also be sources. In fact, any prolonged period of adversity without adequate adult support can be harmful (2). This harm (in the form of toxic stress) affects both mind and body, leading to increased risk of chronic illness, all of the leading causes of death, and the focus of this article: obesity.

Toxic Stress Leads to Obesity

Toxic stress strongly affects the hypothalamus-pituitary-adrenal (HPA) axis. The HPA-axis is a critical player in the body’s ability to maintain basal homeostasis and to respond to stress (3). It regulates levels of cortisol in the body, which plays a role in memory, emotion, learning, inflammatory response, and the storage and utilization of glucose as easy energy to fuel the fight-or-flight response (4,17). After short periods of very high stress (traumatic events), or longer periods of moderate to high stress (chronic stress), the body begins to adapt to the continually increased levels of cortisol in a few key ways that are all precursors to obesity (4).

Stress-Induced Cortisol Dysregulation

Disrupted levels of cortisol lead to the accumulation of fat in adipose tissue, especially in central (abdominal) adipose tissue (5). Further, cortisol affects mood and emotion, which can increase appetite, including increasing cravings for foods high in sugar and fat. This craving occurs in part to fuel glucose metabolism that creates quick energy for the fight-or-flight response (5). This can lead to unhealthy behaviors to deal with chronic stress, such as patterns of eating high-caloric (sugary and fatty) foods, lack of control, and binge eating (5, 16). Some studies have even found that episodes of stress in these individuals can cause dissociation and lower levels of cognition and self-awareness, which can lead to overeating without actually being aware of it (5,16). So, not only is the dysregulated level of cortisol increasing fat accumulation, but the easily adapted behaviors of binge or overeating compound the potential for weight gain.

The Vicious Cycle of Disrupted Sleep

Another aspect of childhood experiences influencing adult weight gain is disrupted sleep. The correlation between the HPA-axis, lowered sleep quality and duration, and obesity has been well documented (3). Because sleep moderates both the neuroendocrine system (of which the HPA-axis is a part) and glucose metabolism, inadequate sleep has been associated with a higher BMI (6). Further, chronic lack of sleep leads to higher levels of cortisol in the evening, as well as increased appetite late at night, both of which affect sleep quality (6). This leads to a vicious cycle of weight gain, chronic stress, and decreased sleep, all of which feed into each other.

Effects of Inflammation, Gut Health, and Mental Health on Obesity

Experiencing adverse childhood experiences also correlates with increased inflammation overall, as well as an exaggerated inflammatory response to life’s stressors experienced as an adult (7). Obesity is also associated with chronic low-grade inflammation; pro-inflammatory molecules become overabundant in areas of increased adipose tissue (8). This over-abundance can lead to dysregulation of glucose metabolism, which, as discussed above, may already be impaired.