Table 1.

Participant characteristics

	TD (n = 55)	ID (n = 48)	P-value†
Age, mean (SD)	5.9 (1.7)	6.0 (1.8)	0.79
Male, n (%)	32 (58%)	32 (67%)	0.38
Race, White, n (%)	21 (38%)	26 (54%)	0.10
Parent graduated college, n (%)	41 (75%)	29 (60%)	0.13
Diagnosis, n (%)
Down syndrome	—	26 (54%)	—
Probable autism spectrum disorder‡	—	30 (63%)	—
Other	—	5 (10%)	—
Vineland Adaptive Behavior Composite Standard Score, mean (SD)	—	65.2 (7.9)
DAS General Conceptual Ability, mean (SD)	—	49.5 (13.4)
Special diets, n (%)
Gluten-free	0	5 (10%)§	0.02
Lactose-free	0	5 (10%)	0.02
Casein-free	1 (2%)	3 (6%)	0.33
BMI z-score, mean (SD)	0.4 (1.0)	1.2 (1.0)¶	<0.001
BMI percentile, mean (SD)	60.2 (28.1)	80.7 (21.5)¶	<0.001
Overweight, n (%)	5 (9%)	6 (13%)¶	0.52
Obese, n (%)	7 (13%)	17 (37%)¶	0.004

^†t-test for continuous variables and chi-squared test for categorical variables.

^‡As assessed by the ASRS.

^§n = 47.

^¶n = 46.

BMI, body mass index; DAS, Differential Ability Scales; ID, intellectual disability; SD, standard deviation; TD, typically developing.