Cross-national time trends in adolescent body weight perception and the explanatory role of overweight/obesity prevalence

Figures & data

Table 1. Characteristics of the study sample.

Variable	n (%)
Total	746,121
Number of countries/regions	41
Survey wave
2002	133,334 (17.8)
2006	160,906 (21.6)
2010	160,746 (21.5)
2014	147,351 (19.8)
2018	143,784 (19.3)
Gender
Boys	365,364 (49.0)
Girls	380,757 (51.0)
Age group
11 years	227,640 (30.5)
13 years	255,085 (34.2)
15 years	263,395 (35.3)
Body weight perception
Correct weight perception	454,415 (60.9)
Underestimation weight status	102,425 (13.7)
Overestimation weight status	189,281 (25.4)
Overweight/obese	107,627 (14.4)
Family affluence
Low	147,141 (19.7)
Medium	448,411 (60.1)
High	150,569 (20.2)

Note: Data are unweighted.

Table 2. Time trends in body weight perception and the explanatory role of overweight/obesity prevalence.

	Model 1 OR (95% CI)	Model 2 OR (95% CI)	Model 3 OR (95% CI)
Correct weight perception
Log likelihood value	−497121.16	−495038.22	−495036.13
Fixed effects
Survey year	1.001 (1.001;1.002)**	1.001 (1.000;1.002)	1.001 (1.000;1.002)
Being girl	0.742 (0.735; 0.749)***	0.739 (0.732; 0.746)***	0.739 (0.732; 0.746)***
Age	0.974 (0.971;0.977)***	0.974 (0.971;0.976)***	0.974 (0.971;0.976)***
Medium FAS^a	1.040 (1.028;1.053)***	1.041 (1.029;1.054)***	1.041 (1.029;1.054)***
High FAS^a	1.028 (1.013;1.043)***	1.034 (1.019;1.050)***	1.034 (1.019;1.050)***
Country overweight/obesity prevalence	-	-	1.011 (1.001;1.022)*
Random effects
Country variance	-	0.023 (0.015;0.036)	0.021 (0.014;0.033)
LR test vs. logistic model (chibar2)	-	4165.87***	3838.55***
Underestimation weight status
Log likelihood value	−289192.29***	−286326.38	−286311.97
Fixed effects
Survey year	1.017 (1.016;1.018)***	1.015 (1.014;1.016)***	1.015 (1.014;1.016)***
Being girl	0.400 (0.394;0.405)***	0.396 (0.390;0.401)***	0.396 (0.390;0.401)***
Age	1.014 (1.010;1.018)***	1.010 (1.005;1.014)***	1.009 (1.005;1.014)***
Medium FAS^a	0.878 (0.863;0.893)***	0.881 (0.866;0.896)***	0.881 (0.866;0.896)***
High FAS^a	0.810 (0.793;0.828)***	0.826 (0.808;0.844)***	0.826 (0.808;0.844)***
Country overweight/obesity prevalence	-	-	1.047 (1.033;1.062)***
Random effects
Country variance	-	0.078 (0.050;0.121)	0.038 (0.025;0.60)
LR test vs. logistic model (chibar2)	-	5731.82***	2815.03***
Overestimation weight status
Log likelihood value	−406635.69	−400278.41	−400268.66
Fixed effects
Survey year	0.987 (0.986;0.988)***	0.989 (0.988;0.990)***	0.989 (0.988;0.990)***
Being girl	2.622 (2.593;2.651)***	2.679 (2.649;2.709)***	2.679 (2.649;2.709)***
Age	1.025 (1.022;1.028)***	1.030 (1.027;1.033)***	1.030 (1.027;1.033)***
Medium FAS^a	1.035 (1.020;1.049)***	1.028 (1.014;1.043)***	1.028 (1.014;1.043)***
High FAS^a	1.107 (1.089;1.126)***	1.083 (1.065;1.102)***	1.083 (1.065;1.102)***
Country overweight/obesity prevalence	-	-	0.954 (0.936;0.972)***
Random effects
Country variance	-	0.110 (0.071;0.170)	0.068 (0.044;0.106)
LR test vs. logistic model (chibar2)	-	12714.57***	8415.10***

Note: n = 746,121. OR indicate odds ratio; CI, confidence interval; FAS, Family Affluence Scale; LR test, likelihood ratio test. ^a Low FAS is reference group. *p < .05. **p < .01. ***p < .001.

Model 1: included survey year (as a continuous variable), gender, age, and family affluence on the individual level.

Model 2: additional included country on the second level.

Model 3: additional included country-level overweight/obesity prevalence.

Table 3. Time trends in body weight perception and the explanatory role of country-level overweight/obesity prevalence stratified by gender.

	Boys (n = 365,364)			Girls (n = 380,757)
	Model 1 OR (95% CI)	Model 2 OR (95% CI)	Model 3 OR (95% CI)	Model 1 OR (95% CI)	Model 2 OR (95% CI)	Model 3 OR (95% CI)
Correct weight perception
Log likelihood value	−237548.73	−236971.82	−236971.67	−259409.78	−257360.35	−257355.21
Fixed effects
Survey year	0.995 (0.994;0.997)***	0.995 (0.994;0.997)***	0.995 (0.994;0.997)***	1.007 (1.006;1.008)***	1.006 (1.005;1.007)***	1.006 (1.005;1.007)***
Age	0.993 (0.989;0.997)**	0.994 (0.989;0.998)**	0.994 (0.989;0.998)**	0.958 (0.955;0.962)***	0.955 (0.952;0.959)***	0.955 (0.952;0.959)***
Medium FAS^a	1.066 (1.047;1.085)***	1.065 (1.046;1.084)***	1.065 (1.046;1.084)***	1.017 (1.000;1.038)	1.027 (1.010;1.045)**	1.027 (1.010;1.045)**
High FAS^a	1.070 (1.047;1.093)***	1.066 (1.043;1.089)***	1.066 (1.043;1.089)***	0.988 (0.967;1.009)	1.010 (0.989;1.031)	1.010 (0.989;1.031)
Country overweight/obesity prevalence	-	-	0.997 (0.989;1.006)	-	-	1.024 (1.010;1.038)**
Random effects
Country variance	-	0.015 (0.010;0.024)	0.015 (0.010;0.024)	-	0.046 (0.030;0.072)	0.036 (0.023;0.056)
LR test vs. logistic model (chibar2)	-	1153.80***	1144.89***	-	4098.86***	3326.72***
Underestimation weight status
Log likelihood value	−177005.27	−175489.07	−175478.24	−110582.88	−109061.7	−109045.31
Fixed effects
Survey year	1.015 (1.013;1.016)***	1.013 (1.011;1.014)***	1.013 (1.011;1.014)***	1.022 (1.020;1.024)***	1.020 (1.017;1.022)***	1.020 (1.017;1.022)***
Age	1.104 (1.099;1.110)***	1.101 (1.095;1.106)***	1.101 (1.095;1.106)***	0.865 (0.859;0.871)***	0.858 (0.852;0.864)***	0.858 (0.852;0.864)***
Medium FAS^a	0.902 (0.883;0.921)***	0.903 (0.884;0.923)***	0.903 (0.884;0.923)***	0.836 (0.812;0.860)***	0.851 (0.827;0.876)***	0.851 (0.826;0.875)***
High FAS^a	0.860 (0.838;0.883)***	0.869 (0.846;0.892)***	0.869 (0.846;0.892)***	0.722 (0.696;0.749)***	0.752 (0.724;0.780)***	0.752 (0.724;0.780)***
Country overweight/obesity prevalence	-	-	1.038 (1.024;1.052)***	-	-	1.063 (1.046;1.082)***
Random effects
Country variance	-	0.062 (0.040;0.096)	0.036 (0.023;0.056)	-	0.128 (0.83;0.199)	0.057 (0.036;0.089)
LR test vs. logistic model (chibar2)	-	3032.41***	1666.81***	-	3042.36***	1369.87***
Overestimation weight status
Log likelihood value	−162382.93	−160021.16	−160014.67	−242587.15	−238249.03	−238238.61
Fixed effects
Survey year	0.992 (0.990;0.993)***	0.994 (0.992;0.995)***	0.994 (0.992;0.995)***	0.985 (0.984;0.986)***	0.987 (0.986;0.988)***	0.987 (0.986;0.988)***
Age	0.906 (0.901;0.911)***	0.908 (0.903;0.913)***	0.908 (0.903;0.913)***	1.103 (1.098;1.107)***	1.111 (1.106;1.115)***	1.111 (1.106;1.115)***
Medium FAS^a	1.011 (0.988;1.034)	1.012 (0.989;1.036)	1.012 (0.989;1.036)	1.050 (1.031;1.068)***	1.032 (1.014;1.051)**	1.032 (1.014;1.051)**
High FAS^a	1.058 (1.029;1.088)***	1.056 (1.026;1.086)***	1.056 (1.026;1.086)***	1.139 (1.114;1.164)***	1.098 (1.074;1.123)***	1.098 (1.074;1.123)***
Country overweight/obesity prevalence	-	-	0.962 (0.944;0.981)***	-	-	0.949 (0.930;0.968)***
Random effects
Country variance	-	0.101 (0.065;0.157)	0.073 (0.047;0.114)	-	0.128 (0.083;0.198)	0.077 (0.050;0.119)
LR test vs. logistic model (chibar2)	-	4723.55***	3377.81***	-	8676.24***	5701.97***

Note: OR indicate odds ratio; CI, confidence interval; FAS, Family Affluence Scale; LR test, likelihood ratio test. ^a Low FAS is reference group. * p < .05.** p < .01.*** p < .001.

Model 1: included survey year(as a continuous variable), age, and family affluence on the individual level.

Model 2: additional included country on the second level.

Model 3: additional included country-level overweight/obesity prevalence.

Table 4. Time trends in body weight perception and overweight/obesity within countries.

	Correct weight perception		Underestimation weight status		Overestimation weight status		Overweight/obesity
Country	2002	Change per year OR (95% CI)	2002	Change per year OR (95% CI)	2002	Change per year OR (95% CI)	2002	Change per year OR (95% CI)
Austria	60.6	1.003 (0.997;1.008)	13.4	1.017 (1.009;1.026)***	26.0	0.989 (0.984;0.995)***	13.5	1.022 (1.014;1.029)***
Armenia	61.0	0.997 (0.983;1.011)	14.0	1.014 (0.997;1.031)	25.1	0.990 (0.972;1.007)	12.3	1.016 (0.996;1.035)
Belgium (Flanders)	60.3	1.008 (1.003;1.013)**	13.2	1.010 (1.002;1.018)*	26.5	0.988 (0.983;0.993)***	13.3	1.011 (1.004;1.019)**
Belgium (Wallonia)	60.7	1.002 (0.996;1.008)	13.4	1.029 (1.020;1.039)***	25.9	0.986 (0.980;0.992)***	13.5	1.023 (1.015;1.032)***
Bulgaria	60.6	0.983 (0.976;0.990)***	13.9	1.046 (1.036;1.057)***	25.5	0.993 (0.985;1.001)	13.7	1.031 (1.021;1.041)***
Canada	60.8	1.005 (1.000;1.010)*	14.4	1.000 (0.990;1.001)	24.4	0.996 (0.991;1.001)	14.9	1.013 (1.008;1.019)***
Croatia	61.3	1.002 (0.998;1.007)	13.9	1.016 (1.010;1.023)***	24.8	0.982 (0.977;0.988)***	13.7	1.022 (1.016;1.029)***
Czech Republic	60.8	1.001 (0.998;1.005)	14.2	1.028 (1.023;1.033)***	25.0	0.974 (0.970;0.979)***	13.6	1.028 (1.022;1.034)***
Denmark	60.6	0.993 (0.987;0.998)**	13.3	0.996 (0.987;1.005)	26.1	1.010 (1.004;1.016)**	13.2	0.989 (0.981;0.998)*
England	60.6	0.998 (0.990;1.006)	13.7	0.998 (0.986;1.009)	25.7	1.004 (0.995;1.013)	13.6	0.979 (0.968;0.990)***
Estonia	60.8	0.992 (0.987;0.997)**	13.7	1.031 (1.024;1.039)***	25.5	0.990 (0.984;0.995)***	13.5	1.062 (1.054;1.070)***
Finland	61.0	1.009 (1.004;1.014)***	13.5	0.986 (0.979;0.993)***	25.4	0.997 (0.991;1.003)	13.6	1.006 (1.000;1.013)
France	61.1	1.000 (0.996;1.003)	13.1	1.010 (1.003;1.016)**	25.8	0.996 (0.992;1.001)	13.2	1.000 (0.994;1.006)
Germany	60.4	1.019 (1.014;1.023)***	13.5	1.006 (0.998;1.013)	26.1	0.976 (0.971;0.981)***	13.5	1.022 (1.015;1.029)***
Greece	61.0	0.984 (0.979;0.990)***	14.3	1.047 (1.040;1.054)***	24.8	0.977 (0.970;0.984)***	14.0	1.012 (1.005;1.018)***
Greenland	60.9	1.001 (0.988;1.015)	13.7	0.981 (0.964;0.998)*	25.4	1.018 (1.000;1.035)*	13.6	1.010 (0.994;1.027)
Hungary	60.8	1.013 (1.008;1.019)***	13.6	1.005 (0.997;1.013)	25.6	0.981 (0.975;0.987)***	13.7	1.029 (1.022;1.037)***
Iceland	61.5	1.003 (0.997;1.009)	13.7	1.015 (1.007;1.024)***	24.8	0.984 (0.977;0.991)***	13.6	1.000 (0.993;1.008)
Ireland	60.7	0.988 (0.978;0.997)*	13.7	1.018 (1.003;1.032)*	25.6	1.005 (0.994;1.016)	13.5	1.001 (0.988;1.015)
Israel	60.7	0.994 (0.987;1.001)	13.8	1.026 (1.016;1.036)***	25.5	0.990 (0.982;0.998)*	13.4	1.027 (1.016;1.037)***
Italy	61.3	0.993 (0.988;0.998)*	13.6	1.006 (0.998;1.013)	25.1	1.006 (1.000;1.013)	13.8	1.002 (0.996;1.009)
Latvia	60.9	1.008 (1.002;1.013)**	13.7	1.019 (1.011;1.027)***	25.5	0.978 (0.972;0.984)***	13.4	1.076 (1.067;1.085)***
Lithuania	60.8	1.000 (0.995;1.005)	13.6	1.027 (1.019;1.035)***	25.6	0.984 (0.978;0.990)***	13.2	1.078 (1.069;1.088)***
Luxembourg	60.7	1.018 (1.010;1.025)***	13.5	1.037 (1.025;1.050)***	25.8	0.964 (0.956;0.972)***	13.6	1.033 (1.023;1.044)***
Macedonia	61.1	1.000 (0.992;1.008)	13.9	1.077 (1.066;1.087)***	25.0	0.926 (0.916;0.936)***	13.8	1.053 (1.046;1.060)***
Malta	60.9	1.009 (1.000;1.019)*	13.9	1.004 (0.993;1.015)	25.3	0.977 (0.965;0.989)***	13.8	1.012 (1.002;1.022)***
Netherlands	60.4	1.010 (1.005;1.016)***	13.2	0.984 (0.975;0.994)**	26.4	0.993 (0.988;0.999)*	13.1	1.010 (1.000;1.019)*
Norway	60.7	1.002 (0.996;1.008)	13.4	1.029 (1.020;1.039)***	25.9	0.986 (0.980;0.992)***	13.5	1.023 (1.015;1.032)***
Poland	59.9	1.009 (1.004;1.013)***	13.7	0.999 (0.993;1.005)	26.4	0.990 (0.985;0.995)***	13.5	1.048 (1.042;1.055)***
Portugal	60.9	1.013 (1.008;1.019)***	13.8	0.992 (0.985;0.999)*	25.3	0.988 (0.982;0.994)***	13.9	1.000 (0.994;1.007)
Romania	61.0	1.023 (1.015;1.031)***	13.9	0.986 (0.977;0.996)**	25.2	0.979 (0.970;0.988)***	13.6	1.038 (1.028;1.049)***
Russia	61.5	0.961 (0.957;0.966)***	13.5	1.045 (1.038;1.052)***	25.0	1.025 (1.020;1.031)***	13.1	1.058 (1.051;1.065)***
Scotland	60.6	0.997 (0.989;1.004)	13.6	1.002 (0.991;1.014)	25.7	1.003 (0.994;1.011)	13.6	1.008 (0.998;1.019)
Slovakia	61.0	0.977 (0.969;0.984)***	13.9	1.004 (0.994;1.013)	25.1	1.034 (1.025;1.044)***	13.6	1.048 (1.037;1.059)***
Slovenia	60.7	1.019 (1.014;1.023)***	13.6	1.016 (1.008;1.023)***	25.7	0.968 (0.963;0.973)***	13.8	1.013 (1.006;1.019)***
Spain	60.7	1.006 (1.002;1.011)**	14.0	1.000 (0.995;1.006)	25.2	0.991 (0.985;0.996)**	13.9	0.992 (0.987;0.998)**
Sweden	60.9	0.996 (0.990;1.001)	13.6	1.010 (1.002;1.017)*	25.5	1.000 (0.994;1.006)	13.4	1.024 (1.016;1.032)***
Switzerland	60.7	1.001 (0.996;1.005)	13.4	1.019 (1.011;1.026)***	26.0	0.991 (0.986;0.996)***	13.1	1.023 (1.015;1.030)***
Ukraine	61.0	0.995 (0.991;1.000)	13.4	1.003 (0.996;1.011)	25.6	1.004 (0.999;1.009)	13.1	1.036 (1.028;1.044)***
Wales	60.7	0.996 (0.990;1.001)	13.7	1.000 (0.992;1.007)	25.6	1.006 (0.999;1.012)	13.8	0.991 (0.984;0.997)**
USA	61.0	1.019 (1.008;1.030)***	13.9	1.023 (1.010;1.037)**	25.1	0.946 (0.934;0.959)***	14.2	1.024 (1.013;1.036)***

Note: OR indicate odds ratio; CI, confidence interval; USA, United States of America. Analyses are adjusted for gender, age, and family affluence.

*p < .05.**p < .01.***p < .001.

Table 5. Time trends in overweight/obesity stratified by gender.

	Total (n = 746,121)		Boys (n = 365,364)		Girls (n = 380,757)
	Model 1 OR (95% CI)	Model 2 OR (95% CI)	Model 1 OR (95% CI)	Model 2 OR (95% CI)	Model 1 OR (95% CI)	Model 2 OR (95% CI)
Overweight/obesity
Log likelihood value	−304102	−299749.97	−168564.2	−166050.19	−135367.43	−133328.08
Fixed effects
Survey year	1.023 (1.022;1.024)***	1.024 (1.023;1.025)***	1.020 (1.019;1.022)***	1.020 (1.019;1.022)***	1.027 (1.025;1.028)***	1.029 (1.027;1.031)***
Being girl	0.617 (0.609;0.625)***	0.615 (0.606;0.623)***	-	-	-	-
Age	0.991 (0.987;0.995)***	0.983 (0.979;0.987)***	1.018 (1.013;1.023)***	1.012 (1.006;1.017)***	0.956 (0.950;0.962)***	0.946 (0.940;0.952)***
Medium FAS^a	0.825 (0.811;0.838)***	0.819 (0.805;0.832)***	0.861 (0.843;0.880)***	0.852 (0.833;0.871)***	0.779 (0.760;0.798)***	0.776 (0.757;0.795)***
High FAS^a	0.687 (0.673;0.701)***	0.686 (0.671;0.700)***	0.749 (0.728;0.769)***	0.744 (0.724;0.765)***	0.608 (0.588;0.628)***	0.609 (0.589;0.629)***
Random effects
Country variance	-	0.105 (0.068;0.163)	-	0.106 (0.069;0.164)	-	0.124 (0.080;0.192)
LR test vs. logistic model (chibar2)	-	8704.06***	-	5028.03***	-	4078.70***

Note: OR indicate odds ratio; CI, confidence interval; FAS, Family Affluence Scale; LR test, likelihood ratio test. ^a Low FAS is reference group. *p < .05.**p < .01.***p < .001.

Model 1: included survey year (as a continuous variable), gender (total only), age, and family affluence on the individual level.

Model 2: additional included country on the second level.

Data availability statement

The data that support the findings are available from the HBSC Data Management Centre at https://www.uib.no/en/hbscdata/113290/open-access.