Persistent social inequality in low intake of vegetables among adolescents, 2002-2014.

Objective: To examine the trend in social inequality in low intake of vegetables among adolescents in Denmark from 2002 to 2014 using occupational social class (OSC) as socio-economic indicator.

Design: Repeated cross-sectional school surveys including four waves of data collection in 2002-2014. The analyses focused on absolute social inequality (difference between high and low OSC in low vegetable intake) as well as relative social inequality (OR for low vegetable intake by OSC).

Setting: The nationally representative Health Behaviour in School-aged Children (HBSC) study in Denmark.

Subjects: The study population was 11-15-year olds (n 17 243).

Results: Low intake of vegetables was defined as less than weekly intake measured by food frequency items. OSC was measured by student reports of parents' occupation. The proportion of participants who reported eating vegetables less than once weekly was 8·9 %, with a notable decrease from 11·9 % in 2002 to 5·9 % in 2014. The OR (95 % CI) for less than weekly vegetable intake was 2·28 (1·98, 2·63) in the middle compared with high OSC and 3·12 (2·67, 3·66) in the low compared with high OSC. The absolute social inequality in low vegetable intake decreased from 2002 to 2014 but the relative social inequality remained unchanged.

Conclusions: The study underscores that it is important to address socio-economic factors in future efforts to promote vegetable intake among adolescents. The statistical analyses of social inequality in vegetable intake demonstrate that it is important to address both absolute and relative social inequality as these two phenomena may develop differently.