Table 1 The descriptions of the variables in the analysis

BMI

Continuous

Child BMI z-score for age based on CDC growth reference. The adjustment was made by the data provider.

BMI1

Continuous

Parent 1’s BMI. Parent 1 is the primary carer who knows best of the child.

BMI2

Continuous

Parent 2’s BMI. Parent 2 is Parent 1’s partner or another adult in the home with a parental relationship to the study child. In most cases this is the biological father, but step-fathers are also common.

FTA

Discrete

Study child’s choice to spend free time. 1: inactive, 2: both, 3: active. The data was collected via the face-to-face interview (F2F) with P1 and the study child.

CD

Discrete

SDQ conduct problems scale (integer 0 to 10) of child. Higher value indicates more severe conduct problem. The SDQ was completed by P1 during the interview questionnaire (P1D).

DP1

Discrete

Parent 1 depression K6 score. Higher value indicates less depression.

EG

Continuous

Total minutes playing electronic games per week. This was reported by P1.

EM

Discrete

SDQ emotional problems scale (integer 0 to 10) of child. Higher value indicates more severe emotional problem. The SDQ was completed by P1 during the interview questionnaire (P1D).

FH

Discrete

Household financial hardship score (0–6). 0: not hard; 6: very hard.

FS

Discrete

Parent 1 financial stress (1–6). 1: prosperous; 2: very comfortable; 3: reasonably comfortable; 4: just getting along; 5: poor; 6: very poor. The data was collected by F2F interview with P1.

INC

Continuous

Usual weekly income for household.

P1E

Discrete

P1’s high school level. Higher value indicates more high school years completed.

P2E

Discrete

P2’s high school level. Higher value indicates more high school years completed.

OD

Discrete

The quality of outdoor environment. Higher value indicates worse outdoor environment. This is derived from several F2F questions about the neighbourhood.

RP1

Discrete

The scale of Parent 1 feeling rushed. Higher value indicates being less rushed. This data was completed by P1 during the interview questionnaire (P1D).

SE

Continuous

The z-score for socioeconomic position among all families. The derivation of this variable can be found in Gibbings et. al. [10].

SL

Discrete

The study child sleep quality. Higher value indicates better sleep quality. The data was collected via the face-to-face interview (F2F) which was conducted with P1 and the study child. This variable is a summation of several questions, such as wheezing, snoring, waking during the night, bed wetting, nightmares and so on.

SEX

Discrete

Gender. 1: male; 2: female.

TV

Continuous

Total minutes watching TV per week. This was reported by P1.

BWZ

Continuous

Birth weight Z-score.

GW

Discrete

Gestation weeks.

FV

Discrete

Serves of fruit and vegetables per day. This was reported by P1.

HF

Discrete

Serves of high-fat food (inc. whole milk) per day. This was reported by P1.

HSD

Discrete

Serves of high-sugar drinks per day.

SLD

Continuous

Sleep time duration (in hours). This was reported by P1.

LOTE

Discrete

Is the child regularly spoken to in a language other than English by you or other relatives, babysitters or at child care, pre-school or school? 1: NO, 2: YES. This data is collected via F2F with P1.