Very low calorie diet versus conventional energy-restricted diet for weight loss before bariatric surgery. A...

In Denmark, achieving ≥ 8% preoperative weight loss within 6 months is a requirement for bariatric surgery (BS). This weight loss is difficult for many patients, postponing their surgery.

This study aimed to optimize pre-surgical weight loss strategies for patients referred to BS.

Aarhus University Hospital, Denmark.

In a prospective study, we evaluated the proportion of patients who underwent BS within 6 months after referral as a marker of successful preoperative weight loss. Furthermore, a randomized controlled trial (RCT) with complete follow-up was performed, comparing very low calorie diet (VLCD) to conventional energy-restricted diet regarding the proportion of patients achieving the mandatory weight loss and undergoing BS within 6 months.

Our prospective study revealed that 67% underwent BS during the entire study period (median time to surgery 8 months), while only 16% underwent BS within 6 months. In the RCT, 65 patients were assigned to either VLCD or conventional diet. The proportion of patients achieving the target weight loss was 94% in the VLCD group vs. 62% in the control group (p < 0.01), and the proportion that underwent BS within 6 months was 86% vs. 38% (p < 0.01), in the VLCD and control group, respectively. VLCD was well tolerated with no adverse effects on surgery time or postoperative complications.

These findings support VLCD as an effective and feasible preoperative intervention to optimize weight loss goals and thereby BS outcomes.