Early 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).
Participants (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.
Diet 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).
Leaving 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.
Physical activity is thought to be important for various health outcomes, but population levels are suspected to be low. There is a lack of large-scale comparable data with which to assess temporal trends and make between-population comparisons. Continued increases in the use of objective monitoring, especially in longitudinal studies, would be very valuable in public health research, and both self-reported and objective data may help to start developing explanations regarding any observed population differences. There is much scope for more international surveillance of physical activity levels using historically comparable measurement tools, as well as making current data available for reanalysis. The continued use of objective measurement tools with transparent research protocols and data reduction strategies would also be beneficial for future research. Prospective objective physical activity data across different countries would allow us to learn from areas successful in maintaining or even increasing population physical activity levels. Physical activity surveillance using objective measures is needed worldwide, not only in Western countries but also in developing countries, as obesity and related metabolic disorders are a global problem, and it is therefore appropriate that the solution is similarly large scale in nature.
Cross-sectional associations between sociocultural factors and objectively-measured physical activity in a sample of 397 children (aged 9) and 213 adolescents (aged 15) were investigated. Associations with children's physical activity were found for mothers' physical activity (Beta = 80, p