Evaluation of peer effects on eating behaviors: a cluster analysis approach

Figures & data

Table 1. Socio-demographic characteristics of the participants and comparison of these characteristics according to BMI and EAT.

				BMI		EAT
Characteristic		n	%	Mean	SD	Mean	SD
Grade	1	127	23.8	22.8	2.4	13.0	7.7
	2	126	23.6	22.4	2.4	11.4	5.3
	3	91	17.1	23.4	2.0	11.0	5.3
	4	69	12.9	23.5	2.3	12.2	7.2
	5	75	14.1	24.1	2.2	15.4	8.4
	6	45	8.4	23.3	2.3	12.4	6.3
	p			F = 6.37, p < .001* ^a^,^b^,^c^,^d		F = 4.59, p < .001*^d^,^e
Hometown in Anatolia	Western	132	25.8	23.0	2.3	11.2	6.0
	Southern	47	9.2	23.0	2.5	12.1	5.8
	Central	138	27.0	23.0	2.4	12.6	7.0
	Northern	49	9.6	23.3	2.3	11.9	7.4
	Eastern	65	12.7	23.6	2.1	12.9	7.7
	Abroad/overseas	80	15.7	22.8	2.4	12.8	6.2
	P			F = 1.22, p = .301*		F = 1.03, p = .400*
Place of residence	Village	60	12.0	23.2	2.1	12.4	6.0
	Town – district	88	17.6	23.3	2.3	12.8	7.6
	City	351	70.3	23.1	2.4	12.3	6.7
	p			F = 0.44, p = .645*		F = 0.16, p = .850*
Sport status	Never	19	3.6	23.0	2.7	9.8	4.4
	Irregular	264	49.5	23.2	2.2	12.7	6.8
	Regular rarely	173	32.5	23.0	2.4	11.6	7.0
	Regular often	77	14.4	23.1	2.7	14.1	7.1
	p			F = 0.25, p = .862*		F = 3.53, p = .015*^,^f
Mother education level	Elementary school	45	8.5	23.4	2.2	12.4	8.4
	Secondary school	194	36.7	23.2	2.3	11.9	6.8
	High school	73	13.8	23.0	2.4	11.9	5.6
	University	102	19.3	23.0	2.5	13.9	8.0
	Postgraduate	115	21.7	23.2	2.4	12.4	5.7
	p			F = 0.31, p = .870*		F = 0.56, p = .183*
Father education level	Elementary school	10	1.9	22.8	1.9	9.3	2.9
	Secondary school	115	21.7	23.3	2.5	12.6	7.6
	High school	56	10.6	23.1	2.5	12.3	6.4
	University	136	25.7	23.1	2.4	12.7	7.5
	Postgraduate	212	40.1	23.1	2.3	12.5	6.2
	p			F = 0.19, p = .946*		F = 0.60, p = .666*
Smoking status	Never smoking	431	80.9	23.0	2.3	12.4	6.9
	Smoking/smoked	102	19.1	23.7	2.4	12.9	6.9
	p			T = 2.90, p = .004**		T = 0.74, p = .460**

Note: Statistically significant differences between a: 2nd-3rd, b: 2nd-4th, c: 5th-1st, d: 5th-2nd, e: 5th-3rd graders, f: never regular oftenly, according to Tukey’s HSD tests.

*One-way ANOVA test, **Independent sample t test was used in the comparison.

Table 2. Comparison of 18 peer groups generated as a result of cluster analysis according to BMI and EAT.

Characteristic	BMI		EAT
	Mean	SD	Mean	SD
Peer group (n)
1 (38)	23.7	2.4	16.8	9.9
2 (38)	22.7	2.0	9.5	4.9
3 (51)	22.3	2.5	12.9	6.2
4 (56)	22.4	2.8	12.3	6.2
5 (36)	22.9	2.1	10.1	2.5
6 (34)	21.8	2.1	11.2	5.7
7 (30)	23.0	1.6	11.0	4.5
8 (32)	22.8	2.0	10.4	5.2
9 (27)	24.6	2.0	11.6	6.4
10 (21)	23.8	1.8	14.9	8.6
11 (30)	23.0	2.4	11.8	6.4
12 (17)	23.9	2.5	8.8	4.2
13 (18)	23.8	2.2	18.4	9.4
14 (32)	23.8	2.4	17.5	8.5
15 (25)	24.8	1.8	10.6	4.8
16 (11)	24.6	1.8	7.7	3.9
17 (14)	22.8	2.0	10.4	3.2
18 (19)	23.0	2.6	16.9	6.5
p	F = 4.09, p < .001*		F = 5.97, p < .001

*One-way ANOVA was used.

Table 3. Evaluation of peer group effect on EAT-40 and BMI level and other covariates by analysis of covariance.

	EAT			BMI
Source	Type III Sum of squares	F	p	Type III Sum of squares	F	p
Grade	299.757	6.445	0.011	5.498	1.021	0.313
Peer group	249.378	5.362	0.021	0.838	0.156	0.693
Smoking	0.440	0.009	0.923	23.168	4.303	0.039