Table 1.

Demographic characteristics and body weight perception according to gender: the CASPIAN-V study.

	Boys	Girls	Total	p
Age (y)	12.39 (12.32–12.46)	12.18 (12.10–12.26)	12.28 (12.23–12.33)	< 0.001*
Weight (kg)	42.31 (41.92–42.74)	40.36 (39.97–40.76)	41.35 (41.06–41.63)	< 0.001*
BMI z-score (LMS method)	−0.57 (−0.51–−0.63)	−0.54 (−0.48–−0.60)	−0.56 (−0.50–−0.62)	0.560
Actual weight (based on BMI)
Underweight	17.4 (16.5–18.3)	14.8 (14.0–15.6)	16.1 (15.5–16.7)	< 0.001*
Normal weight	61.4 (60.4–62.5)	64.7 (63.6–65.9)	63.0 (62.3–63.8)
Excess weight	21.2 (20.3–22.1)	20.5 (19.5–21.5)	20.8 (20.2–21.6)
Body weight perception
Underweight	28.4 (27.4–29.4)	27.5 (26.5–28.5)	28.0 (27.5–28.9)	0.010*
Normal	42.9 (41.8–44.1)	41.4 (40.4–42.6)	42.2 (41.1–42.7)
Excess weight	28.6 (27.6–29.6)	31.0 (30.0–32.1)	29.8 (29.1–30.7)
BMI-BWP agreement
Underestimate	31.8 (30.7–32.9)	29.7 (28.6–30.7)	30.8 (30.1–31.7)	0.010*
Correct estimate	39.9 (38.8–41.0)	41.9 (40.7–43.1)	40.9 (39.9–41.5)
Overestimate	28.3 (27.2–29.4)	28.4 (27.4–29.5)	28.4 (26.7–29.2)
SES
Low	33.6 (32.5–34.7)	33.3 (32.2–34.4)	33.5 (32.8–34.4)	0.080
Moderate	33.8 (32.7–35.0)	32.4 (31.3–33.4)	33.1 (32.3–33.9)
High	32.6 (31.5–33.6)	34.3 (33.1–35.4)	33.4 (32.5–34.1)
School performance
Poor	32.8 (31.7–33.9)	28.8 (27.7–29.8)	30.8 (30.0–31.6)	< 0.001*
Good	67.2 (66.1–68.3)	71.2 (70.2–72.3)	69.2 (68.4–70.0)
Self-perceived health
Poor	18.8 (18.4–20.1)	19.2 (18.0–19.7)	19.0 (18.3–19.7)	0.540
Good	81.2 (79.9–81.6)	80.8 (80.3–82.0)	81.0 (80.3–81.7)
Living area
Rural	28.7 (27.7–29.9)	28.4 (27.3–29.4)	71.4 (70.7–72.1)	0.660
Urban	71.3 (70.1–72.3)	71.6 (70.6–72.7)	28.6 (27.9–27.3)

Data are presented as mean (95% CI) for continuous variables, and percent (95% CI) for categorical variables.

^*p < 0.05 was considered as statistically significant.

BMI= body mass index. BWP= body weight perception.