Stress has been known to lead to many different negative health effects. One such effect is obesity. Stress leads to the storage of fat by releasing the stress hormone, cortisol. Cortisol triggers the release of triglycerides from the liver and relocates them to fat cells in the abdomen. Fat stored in the abdomen is considered to be bad for health as it is strongly linked to heart disease. Cortisol also increases appetite.

The message to many families is that they need to fight the child obesity epidemic by getting their kids to eat right and exercise more. But what if stress is playing a role in the epidemic? Koch et al wanted to see if stress in the family household could be correlated to obesity in children.

Koch et al (2008) studied a sample of over 7000 Swedish families to see if family stress was correlated with obesity in 5-year-olds.  The families were all taking part in another study, the All Babies in Southeast Sweden project (ABIS), which was a prospective study of childhood diabetes.

The families were asked to fill out structured questionnaires to measure their level of stress related to four domains: serious life events, parenting stress, lack of social support and general anxiety/worry. A composite stress score was obtained, as well as individual scores for each of the domains.

In the sample, 4.2% of the children were obese. The composite measure of psychological stress, measuring the additive effect of stress across all four domains at age 5 showed that high stress in the family was related to childhood obesity at age 5. This cross-sectional finding was supported by the longitudinal finding of a relationship between high stress in the family at age 2 and childhood obesity at age 5.

When looking at the individual domains, parenting stress and lack of social support were not significantly correlated to childhood obesity in this study. On the other hand, stress caused by serious life events and parental worries/anxiety were significantly correlated to childhood obesity.  One factor that may have influenced the findings was the high attrition rate among parents not born in Sweden, mothers with no university education and single parents. As these groups tend to struggle financially, it is acknowledged that the lower socioeconomic classes and those with less social support were under-represented in the study.

The study indicates that psychological stress in the family may be a contributing factor for childhood obesity. This is an important finding because it means that simply changing eating behaviours is not enough; instead, families need to be given psychological and social support to help manage stress.

• The study made use of a very large sample.
• The structured questionnaire allowed for relatively easy analysis and could be easily replicated.
• The results were credible. There were similar findings in both a cross-sectional and a longitudinal approach to the data.
• The sample was not representative of the lower classes due to a high attrition rate.
• There could be a cultural bias in the research as Sweden is a highly individualistic culture with low power-distance.
• Actual cortisol levels were not measured, so stress was self-reported. Data triangulation with regard to the level of stress would have made the study stronger.
• Since the findings are correlational, the research is not able to establish a cause and effect relationship between family stress and childhood obesity. However, psychologists do know that there is a link between stress and the retention of fat, so the findings reflect grounded theory.

Koch, FS, A Sepa and J Ludvigsson. Psychological stress and obesity. J Pediatr. 2008 Dec;153(6):839-44. doi: 10.1016/j.jpeds.2008.06.016. Epub 2008 Jul 26.