Preliminary study of the increase in health science students’ body mass index during the Christmas holidays

•Preliminary study of the increase in body mass index in university students.•Study carried out with nursing degree students.•Preparation of reports to avoid weight gain in short periods of time with high food intakes. There is a trend toward an increase in body mass index (BMI) among adolescents over the course of the year. This increase in BMI is more pronounced during vacation periods, when healthy habits are relaxed due to the increase in number of social, family, and festive events, with summer being the period with the greatest increase. The objective of this study was to evaluate changes in weight during Christmas vacation. Changes in weight, BMI, and waist circumference were evaluated in association with adherence to the Mediterranean diet or a low-fat diet. A total of 67 university students participated in this pilot study, 10 men (14.9%) and 57 women (85.1%), with a mean age of 20.37 y (±4.07 y). The first weigh-in was on the day before the start of vacation; there were two more during the vacation and a final one when students returned to the course. In general, a significant increase (P < 0.05) in body weight was found between the first measurement and the ensuing measurements during the holidays. The students with a high-fat diet presented with a more pronounced change in weight, with significant differences being found between weights 1 and 3 and between weights 1 and 4 (P < 0.05). The data show that students gained a significant amount of weight during the Christmas holidays. Although the weight gain was not alarming, it does point to the possibility of weight gain among young adults during vacation periods and may reflect what happens in other social strata.