The freshman year of college as a critical period for weight gain: an initial evaluation.

Prevention of obesity and weight maintenance have become important public health issues. One strategy for prevention of obesity is to identify critical periods of weight gain across the life span. The purpose of this initial evaluation was to determine whether the transition from high school to college is such a critical period. A total of 135 college students were weighed in September and December of their freshman year and a subset also provided data in May. Results showed that statistically significant but modest weight increases occurred during the freshman year for most participants. However, one quarter of participants gained at least 2.3 kg during the first semester of college, and the proportion of participants classified as overweight or obese increased markedly. For this subset of participants, the freshman year of college could be considered a critical period for weight gain. Identifying critical periods for weight gain may be an important first step towards the development of effective obesity prevention programs.