Table 6. Top-20 keyword pairs that show highest growth over time.

ID	Keyword-1	Keyword-2	1993–1997 (%)	1998–2002 (%)	2003–2007 (%)	2008–2012 (%)	Relative growth (%)	Significance (z-score)
1	Bariatric surgery	Laparoscopy	0.02	0.53	0.65	0.16	20.02	0.00
2	Bariatric surgery	Gastric banding	0.02	0.34	0.48	0.15	12.06	0.00
3	Childhood obesity	Nutrition	0.00	0.00	0.01	0.07	10.96	0.00
4	Gastric banding	Sleeve gastrectomy	0.00	0.00	0.01	0.06	10.00	0.00
5	Body mass index	Adipokines	0.00	0.01	0.01	0.05	8.56	0.00
6	Metabolic syndrome	Cohort study	0.00	0.00	0.01	0.05	7.61	0.00
7	Leptin	Body fat	0.02	0.22	0.03	0.02	7.50	0.00
8	Type 2 diabetes	Gastric bypass	0.00	0.00	0.01	0.10	7.37	0.00
9	Leptin	TNF-alpha	0.02	0.21	0.09	0.07	7.19	0.00
10	Body mass index	Waist circumference	0.05	0.38	0.62	0.80	7.18	0.00
11	Complications	Sleeve gastrectomy	0.00	0.00	0.01	0.05	7.13	0.00
12	Body mass index	Children	0.10	0.80	0.77	0.71	7.04	0.00
13	Body mass index	Leptin	0.05	0.41	0.20	0.13	6.81	0.00
14	Children	Prevalence	0.02	0.16	0.05	0.10	6.74	0.00
15	Body mass index	Cohort study	0.02	0.20	0.26	0.17	6.67	0.00
16	Diet	Pregnancy	0.00	0.01	0.01	0.04	6.65	0.00
17	Leptin	Body composition	0.02	0.20	0.06	0.04	6.61	0.00
18	Adolescents	Waist circumference	0.00	0.01	0.02	0.12	5.70	0.00
19	Leptin	Glucose	0.02	0.16	0.03	0.02	5.31	0.00
20	Type 2 diabetes	Roux-en-Y gastric bypass	0.00	0.00	0.01	0.04	5.22	0.00