Women with obesity may share the risk of the disease with their daughters, but not their sons, according to a new University of Southampton study.
Researchers say that more help is needed to support families to lead healthier lifestyles before conception and in early pregnancy to reduce this risk.
The research, published in the Endocrine Society's Journal of Clinical Endocrinology and Metabolism, measured body fat and muscle in 240 children and their parents who took part in the Southampton Women's Survey, a long-running study that tracks the health of mothers and their children.
Children were measured at ages four, six to seven and eight to nine. The parents were measured when their children were eight to nine years of age.
The researchers used this data to determine whether the body mass index (BMI) and the amount of body fat and muscle in the child was related to that of their parents.
They found the girls had a similar BMI and fat mass to their mothers when they were six to seven and eight to nine years old. This suggests that girls born to mothers who have obesity or have high fat mass are at high risk of developing obesity or becoming overweight themselves.
However, the researchers did not find the same association between boys and their mothers, or with either girls or boys and their fathers.
Latest figures estimate that 25.9% of adults in England are obese and a further 37.9% are overweight, while 10.1% of reception age children (age 4-5) were obese in 2021/22, with a further 12.1% being overweight. At age 10-11 (year 6), 23.4% were obese and 14.3% overweight.
Children who are overweight or obese are at high risk of remaining so when they are adults, and people with obesity are at higher risk of developing diabetes, high blood pressure, heart issues, and many other conditions.
The researchers say that while genetics and other factors, such as diet and activity levels, could impact the correlations of body composition between parents and their children, the fact that there was little association between fathers and the children compared to the mothers suggest that the environment during pregnancy plays a role in risk of obesity in later life.
Dr Rebecca Moon, a Clinical Lecturer at the MRC Lifecourse Epidemiology Centre (MRC LEC), University of Southampton and NIHR Southampton Biomedical Research Centre, led the analysis.
She said: "These findings highlight that girls born to mothers who have obesity or have high amounts of body fat may be at higher risk of gaining excess body fat themselves.
"Further studies are needed to understand why this is happening, but our findings suggest that approaches to addressing body weight and composition should start very early in life, particularly in girls born to mothers with obesity and overweight. We need to help families lead healthier lifestyles before they become pregnant so the risk of their children developing obesity is reduced."
The study was funded by the Medical Research Council, the British Heart Foundation, the NIHR Southampton Biomedical Research Centre, the NIHR Oxford Biomedical Research Centre, the Seventh Framework Program, the Biotechnology and Biological Sciences Research Council, the Horizon 2020 Framework Program, and the National Institute on Aging.
