Environmental Factors Determining Body Mass Index (BMI) within 9 Months of Therapy Post Bariatric Surgery-Sleeve Gastrectomy (SG).

Treatment of obesity should be multidirectional and include, in addition to bariatric surgery, changing the key factors of lifestyle and eating habits. The study aimed to assess the impact of bariatric surgery and dietary care on anthropometric measurements, blood pressure, changes in lifestyle, and eating habits of patients within 9 months after the procedure, with the selection of environmental factors determining BMI variation. The study included 30 SG patients before surgery (month zero) and at 1, 3, 6, and 9 months after SG. Patients completed a questionnaire regarding age, sex, place of residence, education, professional activity, number of family members, financial situation, family history of obesity, previous forms of therapy, self-assessment of nutritional knowledge, receiving and following nutritional recommendations, eating habits, frequency of body weight control, leisure time. Body weight, height, waist and hip circumference, and systolic and diastolic pressure were measured, and BMI and WHR (Waist to Hip Ratio) were calculated. Within 9 months after the procedure, the patients' body weight and BMI decreased on average by 26%. Post bariatric surgery, patients changed their eating habits. The influence of bariatric SG surgery and time after surgery was decisive for the normalization of BMI and explained the 33% variation in BMI up to 9 months after the procedure. Other factors important for the normalization of BMI after surgery were: male gender, older age of patients, family obesity (non-modifiable factors), as well as previous forms of therapy related to weight loss before surgery, shortening the intervals between meals and stopping eating at night (modifiable factors). The tested model explained 68% of the BMI variation after SG surgery for all assessed factors. Changes in lifestyle and eating habits in bariatric patients are crucial to maintaining the effect of bariatric surgery.