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Research findings

Gene variant found that may explain toddler weight gain


Illustrasjonsfoto: Colourbox.com
Illustrasjonsfoto: Colourbox.com

Genes are involved in controlling weight gain early in life, according to a study based on data from the Norwegian Mother, Father and Child Cohort Study (MoBa).

  • The researchers found a gene variant in 1 in 4 Norwegian children that seems to affect appetite and energy intake during the first two years of life.
  • The gene variant does not influence adult weight.

Children's body mass index (BMI) changes rapidly during the first years of life. BMI rapidly increases up to around nine months, then decreases until the age of 4–6, before increasing again and stabilising in adolescence. What really drives these changes?

Fact: BMI, is defined as the body weight divided by the square of the height given in metres (kg / m2).

A research group based at the University of Bergen and the Norwegian Institute of Public Health (NIPH) has recently found that a genetic variant in the leptin receptor, the gene that controls appetite regulation, helps control this development.

One in four toddlers have gene variant in the leptin receptor

The researchers found variants in five key genes, all of which were associated with growth and development in children at different time points. The most interesting of these was the previously unknown gene variant in the leptin receptor. This variant, which they found in about one in four children, was strongly associated with BMI from 3 months up to 2 years, before the effect diminished again.

“We had a hypothesis that there could be genetic variants affecting child growth that are not possible to detect in studies done on adults. This has proven to be true as this variant is not associated with BMI in adults”, says first author of the study Øyvind Helgeland, based at the University of Bergen and the NIPH.

Contributes to understanding how children grow

The finding can help us better understand how infants grow since malnutrition and preterm birth are global societal challenges.

About the study

Genes from 14 474 children in MoBa were analysed. Their BMI was measured at 12 timepoints from birth to eight years of age. The researchers then searched for gene variants that could explain differences in BMI.

The study was a collaboration with researchers from the following institutions; Centre for Diabetes Research, University of Bergen, Haukeland University Hospital, the Norwegian Institute of Public Health (Department of Genetics and Bioinformatics, Centre for Fertility and Health, and MoBa), University of Oslo, HUNT Research Centre , Norwegian University of Science and Technology (NTNU), University of Gothenburg , Sahlgrenska University Hospital  and University of Tromsø.

The study is the first large-scale genetics study to investigate age-dependent effects in continuous BMI measurements from birth to 8 years. In addition, the study is the first large-scale genetics study conducted in MoBa, a study that includes 114,000 children and their parents in Norway.


Helgeland, Ø. et al. Genome-wide association study reveals dynamic role of genetic variation in infant and early childhood growth. Nat. Commun. 10, 4448 (2019).