(C) Michał R Janik

Despite the significant clinical benefits from bariatric surgery, many patients were disappointed with the weight loss due to unrealistic expectations. This leads to an abandonment of weight loss goals and may negatively influence the long term outcome. Setting realistic expectations is an important aspect of the preoperative evaluation, education and may be a key success of the treatment. Predict BMI allow to set realistic expectations regarding weight loss after the most popular bariatric procedure - laparoscopic sleeve gastrectomy.


The calculator was based on the results of the research project performed by MR Janik et al.

Full manuscript was published in Videosurgery and Other Miniinvasive Techniques and is available for free - read the full text.



Janik M, Rogula T, Mustafa R, Saleh A, Abbas M, Khaitan L. Setting realistic expectations for weight loss after laparoscopic sleeve gastrectomy. Videosurgery and Other Miniinvasive Techniques. 2019;14(3):415-419. doi:10.5114/wiitm.2019.81661.

PREDICT BMI is a validated tool to calculate expected one year weight loss after Laparoscopic Sleeve Gastrectomy (LSG).

Michał Robert Janik MD, PhD