Table 2.

Basic characteristics of the study participants.

Characteristics		Subjects	Percentage
Gender	Male	167	51.23
	Female	159	48.77
Age	3-4 years	137	42.02
	4-5 years	115	35.28
	5-6 years	74	22.70
Residence area	Xi'an	196	60.12
	Lanzhou	69	21.17
	Xining	61	18.71
Maternal education	Junior and below	36	11.04
	Senior	88	26.99
	College and above	202	61.96
BMI	Underweight	36	11.04
	Normal	187	57.36
	Overweight	30	9.20
	Obesity	73	22.39