Table 1

Potential predictor variables used in analyses

FactorApproximate age of MCS child at data collectionLevel for analysis
Biological
 Child's gender7 yearsMale; female
 Child's ethnicity*7 yearsWhite; mixed; Indian; Pakistani/Bangladeshi; black or black British; other
 Child's body mass index (BMI) †7 yearsUnderweight/ normal weight; overweight/ obese
Social
 Mother's age at birth (years)9 months14–19; 20–29; 30–39; ≥40
 Maternal current occupation‡7 yearsManagerial & professional; intermediate; small employers & own account workers; lower supervisory & technical; semi- routine & routine; non-employed
 Maternal highest academic qualification7 yearsDegree(s)/ post graduate diplomas; higher education/ teaching qualifications/ diplomas; A/ AS/ S-levels; O-levels/ GCSE grades A-C; GCSE grades D-G; other academic qualifications; none of these
 Lone parent status7 yearsNon-lone parent; lone parent
 Number of children in the household (including the cohort child)7 years1; 2–3; ≥4
 Main household language7 yearsEnglish only; English and other language; non-English speaking
 Whether anyone smokes near the child7 yearsYes; no
 Whether the mother is in work or not7 yearsIn work or on leave; not in work or leave
 Main housing tenure7 yearsOwn outright, own mortgage/loan, part own/mortgage; rent from local authority or housing association; rent privately; other
 Type of accommodation7 yearsHouse or bungalow; flat or maisonette; studio, room, bedsit, other
 Household income7 years<£10400; £10400–20800; £20800–31200; £31200–52000; >£52000
Behavioural
 Whether the child has any illnesses or disabilities that limits activity7 yearsYes; no
 Number of days a week the child participates in sport or exercise: parent report7 years≥3 days/week; 2 days/week; 1 day/week; less often/not at all
 Number of hours the child watches TV on weekdays7 yearsLess than an hour/not at all; 1–3 h; 3–5 h; >5 h
 Whether the child was ever breastfed9 monthsYes; no
Environmental
 Access to garden7 yearsYes; no
 Ward type (at time of sampling) §9 monthsAdvantaged; disadvantaged; ethnic
 Government office region7 yearsNorth East; North West; Yorkshire and the Humberside; East Midlands; West Midlands; East of England; London; South East; South West; Wales; Scotland; Northern Ireland; Isle of Man/ Channel Islands
 UK country7 yearsEngland; Wales; Scotland; Northern Ireland
  • *Categorised according to guidelines from the Office for National Statistics.32

  • † Defined using the International Obesity Task Force cut-off for BMI.31

  • ‡Classified according to the National Statistics Socio-economic Classification.33

  • §Wards classified as ethnic if at least 30% of residents were from an ethnic minority group (in the 1991 census), disadvantaged if above the upper quartile of the Child Poverty Index37 and the remaining were advantaged (no ethnic stratum in Wales, Scotland and Northern Ireland24).