Comparison 1.

Gluten and casein free diet versus normal diet

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Autistic traits (social isolation plus bizarre behaviour sub scores of the DIPAB) at 12 months	1	20	Mean Difference (IV, Fixed, 95% CI)	−5.6 [−9.02, −2.18]
2 Cognitive skills at 12 months	1	18	Mean Difference (IV, Fixed, 95% CI)	12.40 [−20.06, 44.86]
4 Motor ability at 12 months	1	20	Mean Difference (IV, Fixed, 95% CI)	−1.5 [−11.88, 8.88]
5 Ecological Communication Orientation (ECO) Language Sampling Summary at week 6	1	13	Mean Difference (IV, Fixed, 95% CI)	1.40 [−92.61, 95.41]
6 Childhood Autism Rating Scale (CARS) at week 6	1	14	Mean Difference (IV, Fixed, 95% CI)	2.40 [−6.66, 11.46]
7 DIPAB sub score - communication and interaction at 12 months (note low score indicates deficit)	1	20	Mean Difference (IV, Fixed, 95% CI)	1.70 [0.50, 2.90]
8 DIPAB sub score - social interaction at 12 months (note high score indicates deficit)	1	20	Mean Difference (IV, Fixed, 95% CI)	−3.2 [−5.20, −1.20]