The influence of inter-generational, early life and environmental factors on the development of adiposity in young adulthood.
This thesis examines the influence of inter-generational, early life and behavioural factors
on adiposity in young adulthood. The work is based on 951 families who participated in
the Barry Caerphilly Growth Study between 1972-9. Children in the study were
followed-up at age 25-26 and invited to attend a clinic where anthropometric
measurements were taken and details collected of current lifestyle. Their middle aged
parents were followed-up for this research project; all parents were sent a health and
lifestyle questionnaire and a sub-sample measured clinically. Parent and offspring
variables were assessed in multivariable models to determine factors associated with
body mass index (BMI) and waist circumference in young adulthood. Offspring variables
included childhood adiposity from birth to age 5 and behaviours and social class at
follow-up; parental variables included maternal BMI during pregnancy and parental
adiposity in middle age.
BMI at age 5 predicted later BMI, though the strength of the association was reduced
after controlling for social class and parental BMI. An inverse relationship between age at
puberty and later adiposity was explained by BMI at age 5. Size at birth was not
significantly associated with later BMI, but children who were smaller at birth had a
higher waist circumference at age 25-26. The BMI of both parents predicted their
offspring's BMI in adulthood. Parental adiposity had little influence on offspring fat
Few significant associations were found with parental or offspring behaviours. One
exception was parental dietary restraint score; higher restraint was associated with lower
BMI and waist circumference in females but not males.
Thus, higher BMI around age 5 or higher parental BMI at any age, may identify
individuals at risk of raised BMI in young adulthood. Size at birth may influence later fat
distribution. Shared family attitudes to weight control may also be important in the
development of adiposity.