Gemini

Aims
Gemini is a large population-based study of twins designed to investigate the genetic and environmental influences on obesity risk, weight gain, and early growth. Gemini have followed twins and their families for over a decade, collecting detailed information about the twins’ growth, eating behaviours, appetite, and the home environment. A key aim of the Gemini study is to create a rich resource of data on early childhood exposures that can be used to assess the determinants of long-term health.

Institution
University College London

Geographic coverage - Nations
England, Wales

Geographic coverage - Regions
Nationwide

Start date
2008

Catalogue record last updated
11/10/2023

Sample type
Birth cohort (twin design)

Sample details
Families with twins born in England and Wales between March and December 2007 were approached on behalf of Gemini by the Office for National Statistics (N = 6,754) in January 2008. 3,435 families agreed to be contacted by the research team, with 2,402 families (36% of the target population) returning a completed baseline questionnaire. The sample comprises of 1,586 same-sex and 816 opposite-sex twin pairs.

Gemini families live across the whole of England and Wales, and the distribution mirrors the population density. The Gemini study includes twins that are comparable in sex, zygosity, gestational age, and birthweight to national averages of twins. However, mothers are somewhat older, and both parents are on average slightly healthier than the national population. As in many cohort studies, there is an over-representation of White–British families within the Gemini cohort.

Sample size at recruitment
2,402 families

Sample size at most recent sweep
987 twins, 492 parents (2020 - Time 9)

Sex
All

Age at recruitment
8 months

Cohort year of birth
2007