Researchers have suggested that body mass index (BMI) may have a genetic explanation, after discovering a 77% chance of children developing obesity at age 17 if their parents were obese at the same age.
A team, including researchers from Tel Aviv University, analysed data from over 1.3 million individuals recorded between 1986 and 2018 during pre-military service screenings in Israel.
BMIs of children aged 17 were compared with those of both their parents when they were the same age. Data was available for 24 per cent of over 4.45 lakh trios included in the analysis.
“Among trios in which both parents had a healthy BMI, the prevalence of (being) overweight or obesity in the offspring was 15.4 per cent, this proportion increased to 76.6 per cent when both parents had obesity,” the authors wrote in the study published in The Journal of the American Medical Association (JAMA) Network Open.
The researchers also found a correlation between the average BMI of parents and that of their child, estimating BMI to be 39% heritable. Specifically, the correlation between father-son BMI was 0.273, suggesting a son’s BMI could be influenced by his father’s by up to 27%.
Additionally, the study revealed a stronger correlation between the BMIs of mothers and daughters compared to mothers and sons. Previous findings indicated that mothers with obesity have a higher likelihood of passing the condition to their daughters than fathers do.
The results highlight gender-specific influences on the heritability of BMI, along with genetic and environmental factors, according to the authors.
