Table 5.

Associations between diet and physical activity and BMI in postpartum women (N = 1292).

	Unadjusted Model		Adjusted Model
	β (95% CI)	p Value	β (95% CI)	p Value
Age, year	0.12 (0.07, 0.16)	<0.001	0.13(0.08, 0.19)	<0.001
Country of birth
Australia (ref.)
Other English-speaking country	0.18 (−1.28, 1.65)	0.802	−0.01(−1.59, 1.58)	0.993
Others	−0.45 (−1.67, 0.77)	0.461	−0.98 (−2.31, 0.36)	0.148
Remoteness
Major cities (ref.)
Inner regional	1.24 (0.07, 2.40)	0.038	0.40 (−0.77, 1.58)	0.496
Other	1.87 (0.45, 3.28)	0.011	1.16 (−37, 3.83)	0.129
Marital status
Not married (ref.)
Married	0.77 (−0.15, 1.70)	0.101	··	··
Education
Bachelor/Graduate diploma (ref.)	1.36 (0.18, 2.55)	0.025	−0.40 (−1.58, 0.78)	0.500
Certificates/Advanced diploma	0.50 (−0.61, 1.61)	0.373	0.83 (−0.20, 1.87)	0.491
No non-school qualification
Household income (cont. decile)	−0.03 (−0.20, 0.14)	0.703	··	··
Occupation
Clerical trade (ref.)
Professional	−0.59 (−2.25, 1.07)	0.482	−0.58 (−2.34, 1.18)	0.511
Assoc. Professional	−0.51 (−2.23, 1.21)	0.559	−0.92 (−2.40, 0.55)	0.216
Other	−0.23 (−2.08, 1.63)	0.807	−0.19 (−1.89, 1.51)	0.828
SEIFA
1st (highest disadvantage) (ref.)
2nd quintile	−0.76 (−2.49,0.97)	0.383	−0.37 (−1.99, 1.24)	0.644
3rd quintile	−1.36 (−3.46, 0.74)	0.199	−1.07 (−3.06, 0.92)	0.286
4th quintile	−1.94 (−3.67, −0.22)	0.028	−1.62 (−3.28, 0.05)	0.058
5th quintile (least disadvantage)	2.30 (−3.75, −0.86)	0.002	−1.73 (−3.12, −0.32)	0.017
Smoking status
Never smoked (ref.)
Current smoker	1.22 (0.20, 2.25)	0.020	0.15 (−0.84, 1.15)	0.761
Ex-smoker	1.49 (0.55, 2.43)	0.002	0.85 (−0.14, 1.84)	0.092
Self-assessed health
Fair/poor (ref.)
Excellent/very good/good	−3.16 (−4.92, −1.41)	0.001	−2.30 (−4.06, −0.54)	0.011
Dieting
Not currently on diet (ref)
Currently on diet	2.81 (1.75, 3.88)	<0.001	2.82 (1.76, 3.89)	<0.001
Vegetables, legumes (categorical)
<1 serves/day (ref.)
≥1 to <3 serves/day	−0.59 (−1.76, 0.57)	0.311	··	··
≥3 to <5 serves/day	−0.90 (−2.33, 0.53)	0.211	··	··
≥5 serves/day	−0.85 (−2.31, 0.60)	0.246	··	··
Vegetables, legumes/beans (binary)
<5 serves/day (ref.)
≥5 serves/day	−0.36 (−1.68, 0.96)	0.587	1.04 (−0.53, 2.62)	0.189
Fruit (categorical)
<1 serves/day(ref.)
≥1 to <2 serves/day	0.73 (−0.40, 1.86)	0.201	··	··
≥2 to <3 serves/day	−0.24 (−1.65, 1.16)	0.731	··	··
≥3 serves/day	−1.49 (−2.94, −0.05)	0.043	··	··
Fruit (binary)
<2 serves/day (ref.)
≥2 serves/day	−1.09 (−2.07, 0.11)	0.030	−0.29 (−1.44, 0.86)	0.617
Grain (cereal) foods (categorical)
Zero or none (ref.)
>0 to <2 serves/day	−0.95 (−3.40, 1.51)	0.442	··	··
≥2 to <4 serves/day	−1.51 (−3.561, 0.49)	0.137	··	··
≥4 to <6 serves/day	−1.36 (−3.53, 0.80)	0.212	··	··
≥6 serves/day	−1.93 (−4.14, 0.28)	0.086
Grain (cereal) foods (binary)
<6 serves (ref.)
≥6 serves	−0.66 (−1.72, 0.41)	0.222	··	··
Whole grain (categorical)
<1 serves/day (ref.)
≥1 to <2 serves/day	−1.34 (−2.35, −0.31)	0.459	−0.85 (−1.86, 0.16)	0.097
≥2 to <3 serves/day	−0.52 (−1.91, 0.87)	0.460	−0.40 (−1.80, 1.00)	0.569
≥3 serves/day	−1.90 (−3.11, −0.69)	0.003	−1.08 (−2.54, 0.38)	0.144
Whole grain (binary)
<48 g/day (ref.)
≥48 g/day	−0.81 (−1.69, 0.73)	0.071	··	··
Whole grain (half of total grains intake)
<50% (ref.)
≥50%	−0.95 (−1.99, 0.09)	0.072	··	··
Milk and/or alternatives (categorical)
<0.5 serves/day (ref.)
≥0.5 to <1.5 serves/day	0.64 (−0.40, 1.68)	0.221	··	··
≥1.5 to <2.5 serves/day	−0.16 (−1.46, 1.14)	0.808	··	··
≥2.5 serves	0.04 (−1.24, 1.32)	0.953	··	··
Milk and/or alternatives (binary)
<2.5 serves/day (ref.)
≥2.5 serves/day	−0.20 (−1.28, 0.88)	0.715	−0.48 (−1.53, 0.57)	0.366
Meats and/or alternatives (categorical)
<0.5 serves/day (ref.)
≥0.5 to <1.5 serves/day	−0.96 (−2.01, 0.09)	0.071	··	··
≥1.5 to <2.5 serves/day	−0.69 (−1.82, 0.44)	0.228	··	··
≥2.5 serves/day	−0.62 (−1.85, 0.62)	0.322	··	··
Meats and alternatives (binary)
<2.5 serves/day (ref.)
≥2.5 serves/day	−0.08 (−1.12,0.97)	0.880	−0.29 (−1.48, 0.90)	0.630
Fibre (g/day)	−0.06 (−0.09, −0.03)	0.001	−0.06 (−0.11, −0.004)	0.034
CHO (%E)	0.01 (−0.03, 0.05)	0.687	··	··
Protein (%E	0.05 (−0.02, 0.132)	0.154	··	··
Total fat (%E)	−0.03 (−0.07, 0.02)	0.197	−0.04 (−0.09, 0.008)	0.097
Trans-fat (%E)	0.40 (−0.76, 1.56)	0.492	··	··
Saturated and trans-fat (%E)	0.02 (−0.10, 0.06)	0.628	··	··
Monosaturated fat (%E)	−0.04 (−0.18, 0.10)	0.545	··	··
Polyunsaturated fat (%E)	−0.14 (−0.31, 0.27)	0.100	··	··
Alcohol (%E)	0.01 (−0.06, 0.08)	0.820	−0.03 (−0.09, 0.04)	0.460
DF (%E)	0.007 (−0.01, 0.03)	0.437	−0.006 (−0.03,0.02)	0.673
SSBs (%E)	0.04 (−0.05, 0.13)	0.340	··	··
Added sugar intake (%E)	0.06 (−0.01, 0.12)	0.075	··	··
Total energy (MJ)	−0.11 (−0.28, 0.04)	0.144	0.15 (0.09, 0.39)	0.209
Total PA (minutes/wk) cont 1	−0.003 (−0.004, −0.001)	0.005	−0.002 (−0.004, −0.001)	0.013
Total PA (minutes/wk) 1
Did not meet recommended guideline (ref.)
Met recommended guidelines	−0.96 (−1.95, 0.03)	0.057	··	··

Data were analysed using linear regression with data presented from univariable and multivariable linear regression analyses. Collinear diet variables were excluded (protein correlate with meat and alternatives, carbohydrate with alcohol, monosaturated fat, polyunsaturated fat, trans-fat saturated fat + trans-fat correlated with total fat, added sugar correlated with SSBs). β, beta-coefficient; CHO, carbohydrate; DF, discretionary foods; MJ, megajoules; MVPA, moderate-vigorous physical activity; PA, physical activity; SEIFA, socio-economic index of disadvantage for areas; SSBs, sugar sweetening beverages, %E, percentage energy. ¹ Total minutes of physical activity undertaken in last week (includes walking for transport + walking for fitness + Moderate + Vigorous time but do not include sessions). Used as continuous and dichotomized as whether physical activity last week met 150 min recommended guidelines. The difference in the number of variables included in the multivariable analysis for pre-pregnant and postpartum women is due to model selection strategies using backward elimination techniques.