Background: The global incidence of pre-obesity and obesity is rising noticeably. Where medical students should be advocating healthy lifestyles, they are actually indulging in unhealthy eating habits and sedentary lifestyle. This is resulting in an increased incidence of obesity in this population.Methods: It was a descriptive cross-sectional study conducted from September 2018 till January 2019 in four medical colleges of Karachi. Sociodemographic profile, body mass index (BMI), food habits, and exercise routine of the students were recorded. Data was entered and analyzed using SPSS version 22 (IBM Corp., Armonk, NY).Results: The mean BMI of the study population was 21.717 ± 4.33 kg/m2 (range: 16.24–38.19). The mean age was 21.345 ± 1.4709 years with a minimum of 17 years and maximum of 25 years. The combined frequency of pre-obese and obese students was 33.2%. Among these, there were more women (60.6%) than men (39.3%). Among these pre-obese and obese students, 55% had breakfast rarely to sometimes, 47.9% took four or more meals per day, 39.3% consumed fast food thrice weekly or more, and 58.1% consumed soft-drinks/juices alternate to every day. Among the students who indulged into binge eating when stressed, 56.9% were pre-obese to obese. The nutritional status of the study sample was significantly associated with female gender, living status with parents, irregular breakfast, infrequent daily meals, increased consumption of fast food and beverages, decreased consumption of red meat, sedentary lifestyle, and altered eating habits when stressed.Conclusion: The incidence of pre-obesity and obesity is noticeably escalating among young adults. If this trend continues, obesity-related complications will form the major chunk of medical illnesses in the near future. Strategies are needed to nip this dilemma in the bud by indulging in healthy and clean eating habits and performing regular physical activity.