Table 4. The trend in overweight between 1980–1997 and 1980–2009 in short (<−1 SD), average stature, and tall (>1 SD) girls and boys expressed as a prevalence ratio.

Age (y)	Short		Average stature		Tall
	1980–1997 Prevalence ratio (95%CI)	1997–2009 Prevalence ratio (95%CI)	1980–1997 Prevalence ratio (95%CI)	1997–2009 Prevalence ratio (95%CI)	1980–1997 Prevalence ratio (95%CI)	1997–2009 Prevalence ratio (95%CI)
Girls
2.0–4.9	0.8 (0.4–1.7)	1.3 (0.5–3.1)	1.1 (0.8–1.5)	1.6 (1.1–2.3)	1.4 (0.8–2.4)	1.4 (0.7–2.7)
5.0–13.9	1.8 (1.1–3.0)	1.2 (0.7–2.2)	1.8 (1.5–2.2)	1.3 (1.0–1.5)	2.1 (1.5–2.8)	1.5 (1.0–2.1)
14.0.17.9	1.2 (0.7–2.1)	1.2 (0.6–2.4)	1.2 (0.9–1.7)	1.5 (1.0–2.1)	1.4 (0.7–2.7)	2.2 (1.1–4.3)
Boys
2.0–4.9	0.7 (0.2–1.7)	1.4 (0.4–4.7)	1.2 (0.9–1.8)	0.9 (0.6–1.5)	2.9 (1.6–5.4)	1.1 (0.5–2.3)
5.0–13.9	1.7 (0.9–3.3)	1.9 (1.0–3.8)	2.2 (1.8–2.7)	1.6 (1.3–2.0)	1.8 (1.3–2.6)	2.1 (1.4–2.9)
14.0.17.9	2.0 (1.0–4.2)	0.9 (0.3–2.5)	1.4 (1.0–2.0)	2.2 (1.5–3.2)	1.8 (0.9–3.6)	1.5 (0.6–3.3)

Positive trend when prevalence ratio >1.

Prevalence ratio =  prevalence of overweight divided by the prevalence in the previous period.