Summary: First identified as a feasible treatment for intractable epilepsy, the ketogenic diet (KD) has recently gained popularity thanks to growing evidence on applications such as weight loss, most importantly, but also NAFLD, cancer, neurologic conditions and chronic pain. As with any treatment, whether pharmacologic or not, the KD might not be an appropriate intervention for every individual, and a number of contraindications have been proposed, now deeply rooted into clinical practice, excluding de facto many patients that could benefit from its use. However, many of these concerns were expressed due to the absence of clinical studies conducted on fragile populations, and an assessment of lately emerged evidence relative to KD safety is currently lacking and much needed. We herein provide a critical revision of the literature behind each safety alert, in order to guide through the treatment options in the case of subjects with an indication to the KD and a borderline safe situation. Based on available evidence, the possible use of this diet as a therapeutic intervention should be assessed on a patient‐to‐patient basis by adequately skilled medical doctors, keeping in mind current recommendations, but reading them through the knowledge of the current state of the art.

Background: Non-alcoholic fatty liver disease (NAFLD) is a major cause of liver disease. Very low-calorie ketogenic diets (VLCKD) represent a feasible treatment as they induce profound weight loss and insulin resistance (IR) improvement. Despite the recognized benefits on NAFLD deriving from pharmacological administration of fibroblast growth factor 21 (FGF21), whose endogenous counterpart is a marker of liver injury, little is known about its physiology in humans. Aim: To identify predictors of NAFLD improvement as reflected by the reduction of the non-invasive screening tool hepatic steatosis index (HSI) in obese patients undergoing a weight loss program. Methods: Sixty-five obese patients underwent a 90-day dietary program consisting of a VLCKD followed by a hypocaloric low carbohydrate diet (LCD). Anthropometric parameters, body composition, and blood and urine chemistry were assessed. Results: Unlike most parameters improving mainly during the VLCKD, the deepest HSI change was observed after the LCD (p = 0.02 and p < 0.0001, respectively). Baseline HOMA-IR and serum FGF21 were found to be positive (R = 0.414, p = 0009) and negative (R = 0.364, p = 0.04) independent predictors of HSI reduction, respectively. Conclusions: We suggest that patients with IR and NAFLD derive greater benefit from a VLCKD, and we propose a possible role of human FGF21 in mediating NAFLD amelioration following nutritional manipulation.

(1) Background: There is still disagreement over how sleeve gastrectomy (SG) affects gastroesophageal reflux disease (GERD). The debate regarding the best option for patients undergoing bariatric surgery who are also affected by GERD and/or hiatal hernia continues to divide the community of bariatric surgeons. While concomitant hiatal hernia repair (SG + HHR) has been proposed as a means of reducing the risk of GERD following SG with varying degrees of success, the addition of a fundoplication (SG + FP) has been suggested in recent years as a way to improve the lower esophageal sphincter’s competency. The aim of this study is to systematically review and meta-analyze the efficacy of SG + HHR versus SG + FP on GERD remission in patients with obesity. (2) Methods: A systematic review of the literature was conducted, and studies analyzing the effects of SG + HHR versus SG + FP on postoperative GERD were included. The methodological quality of included trials was evaluated. The primary outcome was postoperative GERD rate, erosive esophagitis, and 12-month weight loss. Secondary outcomes included postoperative complications and mortality. The PRISMA guidelines were used to carry out the present systematic review (PROSPERO Registration Number: CRD42023405600). (3) Results: Fifteen articles with a total of 1164 patients were included in the meta-analysis; 554 patients underwent SG + HHR while 610 underwent SG + FP. In the SG + HHR group, 58.5 ± 28.9% of subjects presented clinical GERD symptoms compared to 20.4 ± 17.5% postoperatively (p < 0.001). In the SG + FP group, 64.8 ± 39.4% were affected by GERD preoperatively compared to only 5 ± 8.1% postoperatively (p < 0.001). SG + FP patients had a significantly greater GERD remission compared to SG + HHR (p < 0.001). Weight loss was similar between groups (p = 0.125). The rate of leaks was 0.18% and 0.33% in the SG + HHR and SG + FP, respectively (p = 0.657), while perforations were significantly higher after SG + FP compared to the SG + HHR group (3.1% versus 0%, p = 0.002). The mortality rate was significantly greater in the SG + FP group (0.5% versus 0%, p = 0.002). (4) Conclusions: This study revealed that both SG with concomitant HHR and sleeve–fundoplication are effective in terms of reflux resolution and weight outcomes, with superiority of SG + FP in terms of GERD control, despite a greater overall complication rate. Both strategies can therefore be suggested as a suitable alternative variant to a conventional SG in subjects with obesity and concomitant hiatal hernia and/or GERD. Studies with extended follow-up and direct comparisons of these surgical approaches to conventional SG are warranted.