The aim of this review was to report on maternal diet, micronutrient supplementation, and gestational weight gain (GWG) during pregnancy following bariatric surgery and explore the impact on maternal micronutrient deficiency, offspring growth, and perinatal outcomes. A search in PubMed, CINAHL, EMBASE, and ProQuest in July 2022 returned 23 eligible studies (n= 30–20, 213). Diet was reported in two studies, supplementation in six and GWG in 19 studies. Although many women did not achieve healthy GWG, no consistent link with adverse outcomes was reported. Studies were grades II and III on the National Health and Medical Research Council evidence hierarchy and received a neutral or negative score on the Academy of Nutrition and Dietetics Quality Criteria Checklist, suggesting that methodological limitations impact the reliability of reported findings.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11695-023-06565-8.