Background Both physical activity levels and dietary behaviours have consistently been linked with the development of chronic disease, obesity and ill-health in both adult and youth samples. Nationally there are established recommendations of minimum levels of physical activity and fruit and vegetable consumption necessary to promote good health. Developing healthy behaviour is particularly important for young people, as adult behaviours that are detrimental or positive for health and well-being are often established in childhood and adolescence. This paper aims to investigate the prevalence of physical activity and fruit and vegetable consumption and to explore the co-occurrence of these behaviours among young people in the UK, using the newly available Understanding Society study.

Methods This study is part of an ongoing secondary analysis of Understanding Society: The UK Household Longitudinal Study. The analysis sample consisted of 4,395 young people aged 10 - 15 living in the UK in 2009/2010 who participated in the first wave of the study. The prevalence of physical activity and fruit and vegetable consumption within the sample, and patterns of co-occurrence across the two behaviours, were explored descriptively. Multinomial regression models were estimated to investigate the social patterning of the health behaviour co-occurrence patterns, using socio-demographic characteristics of the young person and mother.

Results 85.2% of young people did not meet the government recommendation for fruit and vegetable consumption, reporting less than 5 portions of fruit and vegetable daily. 70.6% of young people did not meet the recommendation for participation in daily physical activity. A small minority did not consume any fruits and vegetables (5.0%); and 6.4% reported participating in physical activity less often than weekly. On examining the patterns across combinations of the two behaviours, most young people did not meet both recommendations (62%), while only 6.1% of young people met both recommendations. Multinomial regression models indicated that gender, ethnicity and religion and socio-economic status were significantly associated with health behaviour patterns.

Conclusion This paper presents an analysis of the most recently available health-risk behaviour data on children from all four countries of the UK. The results indicate that a high proportion of young people do not achieve levels of fruit and vegetable consumption or levels of participation in physical activity considered to be a minimum for good health, and these two behaviours tend to co-occur. The implications of these behaviour patterns and the associations with socio-demographic characteristics are discussed.