Table 3. Data extraction: Meta-analysis and evaluation of certainty of the evidence.

Author (year)	Age (years)	Outcome 1	Outcome 2	Outcome 3	Results of outcome 1	Results of outcome 2	Results of outcome 3	Conclusion	Certainty of evidence
Aceves Martins, et al.32 (2022)	-	NW x OB	NW x OW/OB (DMFT)	-	(I2=78.36%, P=0.3329) (MD:0.16, 95% CI=−0.16,0.48)	(I2=82.21%, P=0.3649) (MD=0.12, 95% CI=−0.14, 0.39)	-	Outcome 1: No association Outcome 2: No association	⨁◯◯◯ Very Low
Alotaibi, et al.20 (2020)	3-14	NW x OB	-	-	(I2=84%, P < 0.001) (OR=2.12; 95% CI: 1.17 to 3.87, p=0.014)	-	-	Increases obesity in the caries group	⨁◯◯◯ Very Low
Manohar, et al.18 (2020)	<6	NW x OW	NW x OB	NW x OB/OW	Cohort design: I2: 0% (PR=1.36, 95% CI: 0.97 to 1.90; p<0.05. Case-control design: (OR=1.09, 95% CI, 0.64 to 1.85, p=0.75).	Cohort design : (PR=1.45, 95% CI: 1.13 to 1.85, p=0.003). Case-control design: (I2=77.7%, p=0.011 OR=1.57, 95% CI, 0.60 to 4.15, p=0.361).	Cohort design: (I2=0%, p=0.393) PR=1.29, 95% CI: 1.03 to1.61; p=0.025). Case-control design: (I2=79.8%, p=0.007) (OR=1.49; 95% CI: 0.68 to 3.25; p=0.317).	Outcome 1: No association. . Outcome 2: Children with obesity have a higher dental caries experience than those with normal weight. Outcome 3: Highest BMI scores had higher dental caries experiences	⨁◯◯◯ Very Low
Singh e Purohit23 (2020)	6-19	NW x UW	NW x OW	NW x OW And NW x OB	All 11 studies: (I2=84%, p< 0.001 OR=1.96, 95% CI, 1.23 to 3.12, p< 0.001). Cohort design: (I2=0%, p=0.54 OR=2.69, 95% CI, 2.05 to 3.53, p<0.001). Permanent dentition: (I2=44%, p=0.15 OR=3.56, 95% CI, 2.21 to 5.74, p<0.001). Primary dentition: (I2=86%, p< 0.001 OR=1.45, 95% CI, 0.78 to 2.69, p=0.24). Early childhood caries: (I2=86%, p<0.001 OR=1.67, 95% CI, 0.88 to 3.17, p=0.12). Dmft index: (I2=32%, p=0.16 Mean difference=0.45, 95% CI, 0.21 to 0.70, p=0.0003).	Dmft index: I2=32%, p=0.16 Mean difference=0.45, 95% CI, 0.21 to 0.70, p=0.0003). Dmfts index: (I2=73%, P=(not reported Mean difference=−0.23, 95% CI, −1.15 to 0.69, p=0.62).	NW x OW: Dmfts: (I2=62%, p=0.0007 Mean difference=−0.39, 95% CI,−0.64 to −0.14, p=0.0002). Dmfs:(I2=0%, p=Not reported; Mean difference=0.14, 95% CI,−0.12 to 0.41, p=0.28). NW x OB: dmft index: (I2=0%, p=0.74 Mean difference=−0.07, 95% CI, −0.31 to −0.17, p=0.57). dmfts: (I2=0%, P=not reported Mean difference=0.35, 95% CI, −0.09 to 0.79, p=0.12)	Outcome 1: All 11 studies: Malnourished children were significantly associated with a higher experience of caries. In longitudinal studies, malnourished children were significantly associated with a higher experience of caries. Permanent dentition: Malnourishment in children was associated with a higher experience of caries. Outcome 2: dmft: Children with greater weight have a greater risk of having ECC when assessed by the dmft index. Outcome 3: No association.	⨁◯◯◯ Very Low
Agelopoulou, et al.22 (2019)	5m-6	NW x UW	NW x OW	NW x OB	Primary teeth: Dmft index: (I2=76%, p=0.0001. Mean difference=0.21, 95% CI, −0.01 to 0.43, p>0.05). Dmfts index: (I2=73.3%, p=0.023. Mean difference=0.23, 95% CI, −1.15 to 0.69, p>0.05). Permanent teeth: DMFT index: (I2=20.2%, P=0.263 Mean difference=−0.07, 95% CI,−0.15 to 0.01, p>0.05).	Primary teeth: Dmft index: (I2=81.3%, P>0.0001. Mean difference=0.07, 95% CI, −0.19 to 0.34, P >.05). dmfs index: (I2=0%, P=0.488 Mean difference=0.14, 95% CI, −0.12 to 0.41, p>0.05). Permanent teeth: DMFT index: (I2=88.4%, p>0.0001. Mean difference=−0.11, 95% CI, −0.46 to 0.25, p>0.05	Primary teeth: dmft index: (I2=95.5%, P<0.0001 Mean difference=0.34, 95% CI, −0.26,0.94, p>0.05). dmfts index: I2=0%, P=0.642 Mean difference=0.35, 95% CI, −0.09,0.79, p>0.05). Permanent teeth: DMFT index: (I2=87.9%, P<0.0001 Mean difference=−0.14, 95% CI, −0.64 to 0.36, p>0.05)	No association between outcomes.	⨁◯◯◯ Very Low
Chen, et al.10 (2018)	<18	NW x UW	NW x OW	NW x OB	Primary teeth dmft index: (I2=76%, P=0.0001Mean difference=0.21, 95% CI, −0.01 to 0.43, p>0.05). dmfs index: I2=73.3%, p=0.023 Mean difference=0.23, 95% CI, −1.15 to 0.69, p>0.05). Permanent teeth DMFT index: (I2=20.2%, p=0.263 Mean difference=−0.07, 95% CI, −0.15 to 0.01, p>0.05).	Primary teeth dmft index: (I2=81.3%, p<0.0001 Mean difference=0.07, 95% CI, −0.19 to 0.34, P >.05) dmfs index: (I2=0%, p=0.488 Mean difference=0.14, 95% CI, −0.12 to 0.41, p>0.05). Permanent teeth (I2= 88.4%, P<0.0001 Mean difference=−0.11, 95% CI, −0.46 to 0.25, p>0.05).	Primary teeth dmft index: (I2=95.5%, p<0.0001. Mean difference=0.34, 95% CI, −0.26 to 0.94, p>0.05). dmfs index: (I2=0%, P=0.642 Mean difference=0.35, 95% CI, −0.09 to 0.79, p>0.05). Permanent teeth DMFT index: (I2=87.9%, p<0.0001 Mean difference=−0.14, 95% CI, −0.64 to 0.36, p>0.05)	No association between outcomes.	⨁◯◯◯ Very Low
Hayden, et al.28 (2013)	<18	NW x OB/OW	NW x OB/OW (Not considering age)	-	All 14 studies: (I2: Not reported, SDM = 0.104, 95% CI, − 0.001 to 0.206, p=0.049). Permanent teeth: (I2: Not reported) SDM = 0.124, 95% CI, −0.053, 0.301, p=0.170). Primary teeth: (I:Not reported) SDM=0.093, 95% CI, − .03 to 0.22, p=0.149)	BMI: I2(Not reported) SDM=0.189, 95% CI, 0.060 to 0.318, p=0.004 IOFT cut offs: (I2: Not reported) SDM = 0.104, 95% CI, 0.028 to 0.180, p=0.008).	-	Outcome 1: A significant association between obesity and caries. Outcome 2: A significant association between caries and obesity was found in the studies using standardized measures to assess child obesity such as BMI-for-age centiles. A significant association between caries and obesity was observed in the studies using standardized measures to assess child obesity such as IOFT cut off for-age centiles.	⨁◯◯◯ Very Low

Footonotes: OB- obesity, OW- overweight, UW- underweight, NW- Normal weight; LBMI - Lower BMI; IOFT -International standards for child obesity; BMI - Body mass index; ECC- Early childhood caries; SDM- Standard difference means, DMFT- decayed, missing, and filled teeth (permanent), dmft- decayed, missing, and filled teeth (primary), dmfs-decayed, missing, and filled surfaces.