Study on Dietary Factors Associated with Obesity Among University Freshmen

【Abstract】 Backgroud Adolescent obesity can lead to various diseases such as type 2 diabetes, fatty liver, and dyslipidemia, while increasing the risk of chronic diseases in adulthood. The development of obesity is influenced not only by food types and intake quantity but also by eating behaviors, including eating speed, meal timing, breakfast frequency, and nighttime eating. However, the association between dietary behaviors and obesity among Chinese adolescents remains unvalidated. Objective To explore the association between dietary behaviors and adolescent obesity, and to provide scientific evidence for effective obesity prevention strategies. Methods A multistage sampling approach was employed: simple random sampling selected 7 provinces nationwide; convenience sampling identified 16 universities within these provinces; cluster sampling included all first-year students aged 16-19 years from the selected universities. Data on current height, weight, and dietary behaviors were collected via self-administered electronic questionnaires. Statistical analyses (chi-square tests and Logistic regression) were performed using SPSS 26.0 and R 4.3.3. Results A total of 16 445 freshmen were surveyed, including 6 710 males (40.80%) and 9 735 females (59.20%), with an average age of (18.04±0.75) years. The highest proportions were in the 18 years (9 618 cases, 58.49%) and 19 years (4 169 cases, 25.35%) age groups, and 5 375 (32.68%) were only children. The overall obesity rate among adolescents was 10.48% (1 723/16 445). The obesity rates of adolescents with much faster, slightly faster, and much slower eating speeds were 15.02% (587/3 908), 9.41% (1 029/10 930), and 6.66% (107/1 607), respectively, and the obesity rate increased with the acceleration of eating speed (P<0.05). The obesity rate of adolescents whose parents were both obese was higher than that of those whose parents were both non-obese [18.89% (17/90) vs 10.10% (1 544/15 293), P<0.05]. There was no significant difference in the obesity rate between males and females whose parents were both obese [16.22% (6/37) vs 20.75% (11/53), P=0.79]; the obesity rate of males whose parents were both non-obese was higher than that of females [12.79% (796/6 225) vs 8.25% (748/9 068), P<0.05]. The obesity rate of adolescents whose fathers were obese but mothers were non-obese was 16.06% (88/548), and the obesity rate of males was lower than that of females [14.29% (38/266) vs 17.73% (50/282), P<0.05]. The obesity rate of adolescents whose mothers were obese but fathers were non-obese was 16.15% (26/161), and the obesity rate of males was higher than that of females [22.03% (13/59) vs 12.75% (13/102), P<0.05]. The results of multivariate Logistic regression analysis showed that males [OR (95%CI)=1.46 (1.31-1.62)], younger age [compared with 19 years old, OR (95%CI) of 16 years old was 1.37 (1.08-1.73), and OR (95%CI) of 17 years old was 1.27 (1.06-1.51)], much faster [OR (95%CI)=2.19 (1.76-2.74)] and slightly faster eating speeds [OR (95%CI)=1.42 (1.15-1.75)], and having breakfast and dinner at home and lunch at school [with an OR (95%CI)=0.86 (0.75-0.98) compared to those who eat at school] were more likely to be obese. Conclusion Key risk factors for adolescent obesity in China include male gender, younger age, parental obesity, fast eating speed, and eating location patterns (e.g., school lunches with home breakfast/ dinner). Additionally, a potential X-chromosome dominant cross-inheritance pattern of obesity was observed, though further validation is required.