ORIGINAL CONTRIBUTIONS The Effect of Pre-Surgery Information Online Lecture on Nutrition Knowledge and Anxiety Among Bariatric Surgery Candidates Shiri Sherf-Dagan 1 & Keren Hod 2 & Limor Mardy-Tilbor 1 & Shir Gliksman 3,4 & Tair Ben-Porat 5 & Nasser Sakran 6,7 & Shira Zelber-Sagi 4,8 & David Goitein 6,9,10 & Asnat Raziel 6 # Springer Science+Business Media, LLC, part of Springer Nature 2018 Abstract Introduction Best practices for patient education in bariatric surgery (BS) remain undefined. The aims of this study were to evaluate the effect of an online lecture on nutrition knowledge, weight loss expectations, and anxiety among BS candidates and present a new tool to assess this knowledge before BS. Methods An interventional non-randomized controlled trial on 200 BS candidates recruited while attending a pre-BS committee. The first 100 consecutive patients were assigned to the control group and the latter 100 consecutive patients to the intervention group and were instructed to watch an online lecture of 15-min 1–2 weeks prior to surgery. All participants completed a BS nutrition knowledge and the state-trait anxiety inventory (STAI) questionnaires at the pre-BS committee and once again at the pre-surgery clinic. Body mass index (BMI), comorbidities, surgery type, marital status, and number of dietitian sessions were obtained from medical records. Results Data for paired study questionnaires scores were available for 128 patients (n = 69 and n = 59 for the control and intervention groups, respectively), with a mean age and BMI of 40.3 ± 11.4 years and 41.3 ± 4.9 kg/m 2 , respectively. The BS nutrition knowledge and the state anxiety scores increased for both study groups at the pre-surgery clinic as compared to the pre- BS committee (P ≤ 0.028), but the improvement in the nutrition knowledge score was significantly higher for the intervention group (P = 0.030). No within or between-group differences were found for the trait anxiety items score. The “dream” and “realistic” weight goals were lower than the expected weight loss according to 70% excess weight loss (EWL) for both study groups at both time-points (P < 0.001 for all). Conclusion Education by an online lecture prior to the surgery improves BS nutrition knowledge, but not anxiety. ClinicalTrials.gov number: NCT02857647. Keywords Weight loss surgery . Education intervention . Nutritional recommendation Introduction The effectiveness of bariatric surgery (BS) is known to be superior than other dietary and medical interventions [1]. However, long-term success following BS is not guaranteed and depends greatly on patient compliance to dietary and lifestyle recommendations and nutritional counseling follow-up [2, 3]. Additionally, bariatric pa- tients who do not adhere to recommended dietary guide- lines following surgery are at higher risk to develop David Goitein and Asnat Raziel are co-senior authors * Shiri Sherf-Dagan shirisherf@gmail.com Keren Hod hodkeren@gmail.com Limor Mardy-Tilbor limorm@assuta.co.il Shir Gliksman shirgliksman@gmail.com Tair Ben-Porat tairbp20@gmail.com Nasser Sakran sakranas@walla.com Shira Zelber-Sagi zelbersagi@bezeqint.net David Goitein david.goitein@sheba.health.gov.il Asnat Raziel drraziel@zahav.net.il Extended author information available on the last page of the article Obesity Surgery https://doi.org/10.1007/s11695-018-3134-y