New clues in childhood obesity puzzle

New evidence from New Zealand’s contemporary longitudinal study Growing Up in New Zealand shows how genes and the environment may interact to promote obesity.

Results in brief

The research investigated the occurrence of a genetic variant in the CREBRF gene in approximately 5,000 children participating in the Growing Up in New Zealand study.

The findings extend previously reported international research which showed that this genetic variant is associated with increased body mass index but decreased the risk of diabetes in Samoan adults, by demonstrating that the genetic variant is:

  • associated with weight and height at four years of age, but not at birth or at two years of age, and that the effect was more pronounced in boys than girls
  • present in Māori and all Pacific populations represented within the Growing Up in New Zealand study

Saliva samples were collected as a source of DNA for analysis from the children (with informed parental consent) during the four-year data collection wave of the Growing Up in New Zealand study.

The discovery suggests that gene-environment interactions may contribute to the development of obesity.

The findings present a new opportunity for early lifestyle interventions to establish healthy growth in all New Zealand children.

The research published online today in the International Journal of Obesity investigated the occurrence of a genetic variant in the CREBRF gene in more than 5,000 children participating in the Growing Up in New Zealand study. Investigators at the University of Auckland Centre for Longitudinal Research – He Ara ki Mua found that this genetic variant was associated with increases in children’s weight, height and waist circumference at four years of age, particularly in boys. They also found this variant was more common in Māori and Pacific children.

Previous international research has connected this genetic variant to increased body mass index in Samoan adults, but this investigation provides new understanding of genetic variation in the New Zealand child population, including across diverse Pacific ethnic groups.

The University of Auckland researchers also discovered that while this DNA variation was related to weight at four years of age, children with the CREBRF variant had no difference in birth weight or weight and height at two years of age. This finding raises the possibility that the environment that people live in is able to modify the effect that the genetic variant has on body size.

Lead investigator Dr Sarah Berry says that this new knowledge offers the potential for evidence-based interventions aimed at establishing healthy growth trajectories from the earliest possible age.

“Our research represents an important step toward understanding the interactions between our diet, lifestyle, and genetic make-up.

“Being able to look at anonymous, population-level data from Growing Up in New Zealand provides us with the unique opportunity to figure out why people are the way they are, and to create new opportunities for improving health outcomes,” says Dr Berry.

The findings contribute important information to national and international strategies to tackle childhood obesity. These include the New Zealand Ministry of Health Childhood Obesity plan, which focuses on food choices and the impact of the environment in the earliest stages of life.

The discovery demonstrates the power and diversity of the internationally recognised Growing Up in New Zealand study, which has collected detailed information about the cohort children and their families over the course of the children’s lives.

The Growing Up in New Zealand cohort reflects the national diversity of the New Zealand child population, including Māori (25 percent), Pacific (21 percent). European (68 percent) and Asian (18 percent) children.

The publication

Berry SD, Walker CG, Ly K, Snell RG, Atatoa Carr PE, Bandara D, Mohal J, Castro T, Marks E, Morton SMB, Grant CC. (2017) Widespread prevalence of a CREBRF variant amongst Māori and Pacific children is associated with weight and height in early childhood. International Journal of Obesity online (20.09.2017)