Parental weight linked to child obesity

19 September 2017 | Research
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A combination of risk factors, such as parents’ weight, in the early life of children could increase their risk of becoming obese

NUS researchers were part of a team who found that a combination of early-life risk factors — including parental weight — in the first 1,000 days of children’s lives could increase their risk of obesity.

Childhood obesity is on the rise in Singapore, with the prevalence of obesity in school-going children having increased from 1.4 per cent in 1976 to 11 per cent in 2013. A number of studies have ascertained the early-life risk factors for childhood obesity, but this is the first study to examine how they combine to influence the risk of childhood obesity in an Asian cohort.

Led by Associate Professor Lee Yung Seng from NUS Yong Loo Lin School of Medicine (NUS Medicine) and Dr Izzuddin Mohd Aris, Senior Tutor with NUS Medicine and currently on an NUS postdoctoral research fellow scholarship at Harvard Medical School, the research team focused on six risk factors — maternal pre-pregnancy body mass index (BMI), gestational weight gain, blood sugar level during pregnancy, breastfeeding duration, paternal BMI at 24 months post-delivery and when solid food was introduced to the child. Explaining the rationale for this, Assoc Prof Lee said, “We chose these six factors because they are potentially modifiable and therefore amenable to intervention. Many of the factors selected in this study are interlinked; for example, both maternal and paternal BMI tend to be correlated, and overweight women are more likely to have increased risk of high blood sugar during pregnancy. In turn, these women are more likely to be referred for planned caesarean delivery, which may reduce the maintenance of breastfeeding duration. Evaluating these risk factors in combination allows us to study the potential public impact on future outcomes.”

Both paternal and maternal obesity play a role in childhood obesity. Furthermore, the probability of child obesity was amplified if both parents were obese. Children who had overweight mothers prior to pregnancy as well as overweight fathers had a 25 per cent combined probability of becoming obese.

As part of the Growing Up in Singapore Towards healthy Outcomes (GUSTO) study, 1,247 pregnant Asian women in their first trimester were recruited from two public hospitals — KK Women’s and Children’s Hospital and National University Hospital — between June 2009 and September 2010. Following up with 858 single-birth babies at 48 months, the researchers found a significant link between the number of risk factors and the risk of childhood obesity, with children exhibiting four or more risk factors facing an 11-fold increase in risk of obesity compared to those exhibiting none.

Additionally, children whose mothers were overweight prior to pregnancy and children who had overweight fathers faced the highest probability of child obesity — 11.8 per cent and 10.6 per cent respectively.

“Both paternal and maternal obesity play a role in childhood obesity. Furthermore, the probability of child obesity was amplified if both parents were obese. Children who had overweight mothers prior to pregnancy as well as overweight fathers had a 25 per cent combined probability of becoming obese,” shared Assoc Prof Lee.

These findings suggest that novel behavioural change interventions which aim to address these early-life risk factors concurrently, such as limiting gestational weight gain; promoting breastfeeding duration; educating mothers regarding timing of solid food introduction, as well as diet or exercise that improve glucose metabolism; and preventing maternal and paternal obesity before conception may be more effective in preventing subsequent risk of childhood overweight or obesity, if they are conducted before pregnancy or during the child’s early life.

The team included NUS Medicine researchers Research Fellow Dr Mya Thway Tint, Associate Professor Lynette Shek, Associate Professor Chong Yap Seng, and Visiting Professor Michael S Kramer; Professor Saw Seang Mei from NUS Saw Swee Hock School of Public Health; Duke-NUS Medical School Adjunct Associate Professor Fabian Yap Kok Peng; Dr Chen Ling Wei, formerly from NUS Medicine; as well as researchers from Agency for Science, Technology and Research; University of Southampton; and University Hospital Southampton NHS Foundation Trust, UK.