TABLE 1.

Quality assessment of the included studies

Study (reference)	Sample size, n	Follow-up, y	Sample method	Control of confounding factors	Anthropometric measures
Gerdin et al. (24)	2303	BMI: 6	Stratification/cluster sampling use to obtain sample representative of country/districts	Yes	Secondary data
		Dental status: 8
Lempert et al. (25)	280	6	Stratification/cluster sampling use to obtain sample representative of country/districts	Yes	Secondary data
Scheutz et al. (17)	145	6	Convenience sample	No	Primary data
Sánchez-Perez et al. (16)	88	4	Convenience sample	Yes	Primary data
Peres et al. (26)	339	12	Some form of cluster sampling use to obtain sample approximately representative of towns	Yes	Secondary data
Peres et al. (27)	352	6	Some form of cluster sampling use to obtain sample approximately representative of towns	Yes	Secondary data
Alvarez (32)	209	4	Random sample	No	Primary data
Kay et al. (28)	985	5.08	Some form of cluster sampling use to obtain sample approximately representative of towns	Yes	Primary data
Werner et al. (23)	230	1.8	Convenience sample	No	Secondary data
Delgado-Angulo et al. (30)	83	3.5	Random sample	Yes	Primary data
Seow et al. (22)	617	0–4	Convenience sample	No	Secondary data
Nelson et al. (18)	224	14	Convenience sample	Yes	Secondary data
Lai et al. (20)	50	4.33	Convenience sample	No	Secondary data
Ismail et al. (31)	788	2	Random sample	No	Not reported
Rajshekar and Laxminarayan (21)	500	3–5.5	Convenience sample	No	Secondary data
Zhou et al. (19)	225	2.67	Convenience sample	Yes	Secondary data
Shulman (29)	4207	2–6	Stratification/cluster sampling use to obtain sample representative of country/districts	No	Secondary data