New employees gain weight in the first 3 years at work: relationship between lifestyle and body weight changes in newly hired male employees in Japan.

Objectives: To evaluate lifestyle and weight changes in new male employees of Japanese companies and clarify the effects of environmental and lifestyle changes on weight changes in early years after joining the company.

Methods: We analyzed health checkup results and lifestyle questionnaires of 160 male graduates hired by a particular company between fiscal years 2009 and 2012. The data obtained included health examinations from the time of the job offer to the fourth year at the company. Weight changes were analyzed using a Friedman test. Lifestyle questionnaires were analyzed using a McNemar test. Twelve male employees who had been with the company for 5-10 years were interviewed about their lives before and after joining. The results were transcribed and analyzed using the Steps for Coding and Theorization method.

Results: Compared with employees' weight at the time of the job offer, their weight at the time of joining the company and in the second and third years increased significantly. (P <.001). An increasing number of participants ate dinner late, missed opportunities for exercise, and did not get sufficient sleep. Interview results indicated that overtime, commuting, and work-related drinking parties among new employees led to late dinners and difficulty in maintaining exercise habits, and that stress at work led to overeating.

Conclusions: New employees gained weight during their first 3 years at the company, and lifestyle changes such as overtime work, late dinners due to drinking parties, and loss of opportunities for exercise during the same period had an impact.