Table 3.

HR and 95% CIs for the risk of routinely diagnosed NAFLD in adulthood in relation to a 1-unit lower BMI z-score below and a 1-unit higher BMI z-score above the median BMI z-score in a cohort of 244 464 children

HR (95% CI) in relation to BMI z-score below (BMI z-score <0) and above the median (BMI z-score >0)
Age	Boys		Girls
	Below	Above	Below	Above
7	1.12 (1.00 to 1.23)	1.02 (0.91 to 1.16)	0.96 (0.85 to 1.08)	0.99 (0.88 to 1.12)
8	1.10 (0.99 to 1.23)	1.06 (0.94 to 1.20)	1.00 (0.88 to 1.13)	1.03 (0.91 to 1.17)
9	1.11 (1.00 to 1.24)	1.07 (0.95 to 1.20)	1.00 (0.88 to 1.13)	1.05 (0.92 to 1.18)
10	1.08 (0.96 to 1.21)	1.08 (0.96 to 1.22)	0.96 (0.84 to 1.09)	1.03 (0.91 to 1.17)
11	1.07 (0.95 to 1.20)	1.09 (0.97 to 1.23)	0.94 (0.83 to 1.08)	1.04 (0.92 to 1.18)
12	1.03 (0.92 to 1.16)	1.05 (0.93 to 1.18)	0.98 (0.86 to 1.11)	1.07 (0.95 to 1.21)
13	1.04 (0.92 to 1.17)	1.10 (0.98 to 1.24)	0.96 (0.84 to 1.09)	1.09 (0.97 to 1.22)

The HRs illustrate the risk associated with each 1-unit difference in BMI z-score away from zero. For example, a HR of 1.12 (CI 1.00 to 1.23) in 7 year old boys with a BMI z-score below the median means that the risk of adult NAFLD increases by 12% per 1-unit lower BMI z-score below zero. A HR of 1.09 (CI 0.97 to 1.22) in 13-year-old girls with a BMI z-score above the median means that the risk of adult NAFLD increases by 9% per 1-unit higher BMI z-score above zero.