How Mom’s vs. Dad’s BMI May Affect Their Children

The Bill & Melinda Gates Foundation recently funded an analysis that concluded that about 75% of all Americans are currently overweight or obese. In 2021, over 15 million children and young adolescents and 172 million adults were overweight or obese. This represents a growing intergenerational challenge in public health. Parental obesity is one of the strongest predictors of childhood obesity. Numerous epidemiological studies have investigated intergenerational effects and have discovered that the children of obese or overweight parents have a much greater risk of becoming obese themselves. Recent studies have investigated potential reasons, such as genetic or environmental factors, for the generational transmission of obesity.

The brain plays an important role. Many obesity-related genes are expressed there and influence how the brain responds to food cues. A recent study used MRI scanning to monitor which brain regions are recruited during food cue tasks. The study examined how neural responses to food cues differ between children with overweight/obese parents as compared to children with normal weight parents. The role of both maternal and paternal BMI on how the child’s brain responds to food cues has never been investigated

The current study examined the relationship between paternal and maternal BMI, both prior to becoming pregnant as well as their current BMI, and the reactivity of their child’s brain to food cues. The children were all healthy and aged 7 to 11 years old at the time of testing. The parents had a broad range of BMI. The study discovered that the children of obese mothers, but not obese fathers, were more likely to be unable to self-regulate how much food they consume.

The biggest changes in the brains of the children with obese mothers occurred in two regions: the dorsolateral prefrontal cortex and anterior cingulate cortex. The activity within these two regions was significantly lower following ingestion of tasty sweets in children with mothers with higher current BMI. These changes are important because the dorsolateral prefrontal cortex and anterior cingulate cortex have key roles in dietary self-regulation. These brain regions are responsible for dietary self-control. They provide the ability to control eating when presented with tasty, appealing foods. When these brain regions are not working properly, it is very difficult to suppress food cravings. Impaired functioning of these brain regions likely underlies why the children of obese mothers become obese themselves.

How do we know this?

When the dorsolateral prefrontal cortex was functionally disrupted by continuous electrical noise stimulation, healthy lean participants reported increased cravings and consumption of snack foods. Apparently, the normal activation of dorsolateral prefrontal cortex is necessary for us to inhibit our craving for tasty unhealthy food.

Overall, these results suggest that deficits in self-control brain circuitry could be one of potential mechanisms explaining the intergenerational effect of obesity. Genetics and the intrauterine environment also play a strong role in familial transmission of obesity. However, even when the child grows up in a different household, they show the same tendency to obesity.

These results have important clinical implications and suggest that intervention programs targeting the mother’s current BMI and the child’s inhibition control may be fruitful for childhood obesity prevention and intervention.