Relevance of Self-reported Behavioral Changes Before Bariatric Surgery to Predict Success After Surgery

International guidelines emphasize the need for multidisciplinary preparation to improve the safety and effectiveness of bariatric surgery (BS), but whether the patient is ready for surgery is difficult to assess. The objective of this study was to explore whether inquiries on dietary habits and physical activity before surgery are predictive of postoperative weight loss.

We prospectively assessed in 78 candidates for BS (age, 43 ± 12 years; M/F, 15/63; weight, 122 ± 17 kg; IMC, 44 ± 5 kg/m²) anthropometric parameters, food intake, and physical activity (Baecke questionnaire) at the beginning and the end of a systematized preoperative preparation (7 ± 2 months) including consultations (mean number 7 ± 2) with a nutritionist, dietician, psychologist, and sports coach.

During the preparation, weight change was zero (±5 kg). In contrast, self-reported caloric intake decreased from 2143 ± 640 to 1906 ± 564 kcal/24 h (p < 0.001) and snacking from 68 to 13% during the preparation. Self-reported physical activity increased (p < 0.05). The decrease in reported caloric intake was positively correlated with the mean number of preoperative consultations attended (R = 0.2885, p < 0.05) but not with the changes in preoperative weight. Postsurgical weight loss (recorded at 6 and 12 months) was correlated with preoperative changes in weight and physical activity but not with preoperative dietary changes.

Self-reported improvement of dietary habits is not a good reflection of actual changes in dietary behavior among candidates for bariatric surgery, as illustrated by the absence of weight changes on average during the preoperative preparation. In contrast to dietary inquiry, self-reported changes in physical activity are predictive of postoperative weight loss after bariatric surgery.