Changes in diet through adolescence and early adulthood: longitudinal trajectories and association with key life transitions

Abstract

BackgroundEarly adulthood is a period associated with poor diet and rapid weight gain. This is also an age of transition, including environmental, social and lifestyle changes which may be associated with changes in diet. We assess longitudinal associations between four early adulthood life transitions (leaving home, leaving education, entering employment, and cohabitation) and changes in consumption of fruit, vegetables, confectionery and sugar-sweetened beverages (SSBs).MethodsParticipants (n = 1100) from the Norwegian Longitudinal Health Behaviour Study, reported data on diet and life transitions on up to eight occasions from age 14 to age 30. Diet data were self-reported in response to questions on intake of fruit, vegetables, confectionery and sugar-sweetened beverages. Growth models were developed to describe changing intake of each of the four diet indicators with age. Fixed-effects regression models assessed associations between the four life transitions and within-individual changes in diet indicators, with adjustment for the remaining transitions and parenthood.ResultsDiet indicators showed quadratic trajectories with age: fruit and vegetable intakes declined from age 14 to ages 23 and 21 respectively, before increasing to age 30. SSB and confectionery intakes increased to age 18, before subsequently decreasing. Leaving the parental home was associated with a decrease in fruit intake of − 0.54 times/week (95% confidence interval (95%CI): -0.87;-0.22) and vegetable intake of − 0.43 times/week (95%CI: -0.70;-0.15). Leaving education was associated with increases in confectionery (0.33 times/week (95%CI: 0.04;0.62)) and SSB intakes (0.49 times/week (95%CI: 0.10;0.87).ConclusionsLeaving home and leaving education are associated with negative changes in diet and may present opportunities for effective diet and obesity intervention. Further study of these transitions is needed to understand the mechanisms mediating associations between life transitions and changes in diet.Electronic supplementary materialThe online version of this article (10.1186/s12966-018-0719-8) contains supplementary material, which is available to authorized users.

Which behaviour change techniques within interventions to prevent weight gain and/or initiate weight loss improve adiposity outcomes in young adults? A systematic review and meta‐analysis of randomized controlled trials

“…The rapid weight gain during young adulthood coincides with marked declines in physical activity (PA) and dietary habits . Specifically, a longitudinal cohort study among 640 Canadian adolescents demonstrated a 24% decrease in PA (equivalent to 1 MET/day) during a 12‐year transition from adolescence to early adulthood.…”

“…This means they have lower intakes of nutrient‐rich foods such as fruits and vegetables, and wholegrains, and higher intakes of energy‐dense, nutrient‐poor foods such as processed meats and sugar‐sweetened beverages . These negative behavioural patterns are attributed to key transitional changes that occur during young adulthood including changes in living situation (ie, moving out of home), social environment and influences (ie, developing stronger peer networks and partner relationships), employment status (ie, starting tertiary education), and financial situation (ie, becoming more financially independent) …”

Changes in physical activity, diet, and body weight across the education and employment transitions of early adulthood: A systematic review and meta‐analysis

“…38 One study investigated changes in diet on leaving full-time education. 9 This study analysed leaving full-time education at any age rather than specifically leaving university, but the study population year period. 39 Miller et al reported no significant changes in MVPA associated with starting employment.…”

“…6 During this period, physical activity decreases, 7 and changes in diet are observed, including decreases in fruit and vegetable consumption in adolescence and increases in diet quality in early adulthood. 8,9 Lifestyle behaviours developed during early adulthood are thought to track into adulthood, influencing later health outcomes. 10 Study of this transitionary period presents an opportunity to understand the impact of changing social and physical environments on lifestyle behaviours, in order to support the development and targeting of public health policy and interventions.…”

Diet quality through adolescence and early adulthood: cross-sectional associations of the Dietary Approaches to Stop Hypertension (DASH) diet index and component food groups with age

“…The period of life from late adolescence to early adulthood is the time when prevalence of overweight and obesity rises the fastest [2], and an important time for understanding changes in determinants of obesity such as diet and physical activity. It is also a time when individuals go through many life transitions, likely to be associated with changes in the determinants of dietary behaviours [3]. Better understanding of how diet changes across this age range will lay a foundation for further investigation of the determinants of changes in diet and evidence on how and when best to intervene to promote establishment of a high quality diet which persists in adulthood.…”