Table 2. Optimal current body size cut-offs for overweight/obesity and underweight by sex and age.

Age (years)			Underweight					Overweight/obesity
		n (%)	CBS	Sensitivity	Specificity	J	LR+	CBS	Sensitivity	Specificity	J	LR+
Boys	All	2451	3	0.748	0.764	0.512	3.2	5	0.870	0.690	0.560	2.8
	12–<13	359 (14.6)	3	0.696	0.882	0.578	5.9	5	0.788	0.734	0.522	3.0
	13–<14	522 (21.3)	3	0.697	0.792	0.488	3.3	5	0.856	0.742	0.597	3.3
	14–<15	527 (21.5)	3	0.779	0.850	0.629	5.2	5	0.900	0.689	0.589	2.9
	15–<16	468 (19.1)	3	0.759	0.737	0.496	2.9	6	0.762	0.889	0.651	6.9
	16–<17	338 (13.8)	3	0.811	0.500	0.311	1.6	5	0.973	0.671	0.644	3.0
	17–<18	237 (9.7)	3	0.758	0.900	0.658	7.6	6	0.619	0.898	0.517	6.1
Girls	All	2967	3	0.580	0.885	0.465	5.0	5	0.652	0.873	0.525	5.1
	12–<13	455 (15.3)	2	0.830	0.645	0.475	2.3	5	0.500	0.954	0.454	11.0
	13–<14	577 (19.4)	3	0.538	0.935	0.474	8.3	5	0.672	0.894	0.566	6.3
	14–<15	581 (19.6)	3	0.901	0.611	0.512	2.3	5	0.654	0.873	0.527	5.2
	15–<16	571 (19.2)	3	0.625	0.814	0.439	3.4	5	0.774	0.850	0.624	5.2
	16–<17	413 (13.9)	3	0.643	0.906	0.549	6.9	5	0.650	0.842	0.492	4.1
	17–<18	370 (12.5)	3	0.658	0.889	0.547	5.9	5	0.800	0.816	0.616	4.4

CBS: current body size; J: Youden index; LR+: positive likelihood ratio.