Pre-Op Weight Loss Improves Bariatric Surgery Outcomes

Patients who lost at least 8% of their excess weight through a low-calorie diet (LCD) immediately before bariatric surgery have more successful long-term outcomes, according to a new study.

Researchers at the Greenville Health System (GHS; Greenville, SC, USA) conducted a study to determine the effect of preoperative excess weight loss (EWL) on postoperative outcomes in 355 patients undergoing primary vertical sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) between 2014 and 2016. The LCD included 1,200 kcal/day (45% carbohydrates, 35% protein, 20% fat), which were consumed through five meal-replacement products and one food-based meal. All patients were also instructed to conduct 30 minutes of moderate to vigorous activity per day.


The LCD was observed for four weeks immediately preceding surgery. The patients were then divided into two cohorts and analyzed according to those who achieved an 8% or higher EWL (224 patients), and those who did not (131 patients). The primary endpoints included percent excess weight loss (% EWL) at 1, 3, 6, and 12 months postoperatively. The results revealed that patients who achieved an 8% or higher EWL were more successful at continued weight loss during the first year after surgery than the patients who did not lose as much weight preoperatively.

The cohort that achieved the target contained a greater proportion of men than did the other group (25.5% vs. 13.7%, respectively), a higher proportion of white patients (84.8% vs. 74.1%), and a higher proportion of patients taking antihypertensive medications (68.3% vs. 57.3%). The two groups had similar rates of preoperative comorbidities and surgery types. In addition, those who achieved the target weight loss had a shorter hospital stay and a higher % EWL at three months, six months, and one year post-operatively. The study was published in the April 2018 issue of the Journal of the American College of Surgeons (JACS).

“These findings suggest that surgeons and clinical care teams should encourage healthy eating and exercise. The program helped patients establish healthy eating habits, establish portion control and learn what a healthy meal looks like,” said lead author clinical nutrition specialist Deborah Hutcheon, DCN. “Weight loss from the liver and abdominal cavity helps to improve surgical access, which may be why surgical times and recovery periods went down.”

“We call it the honeymoon period of bariatric surgery. After a year or year and a half, your body starts to figure out what it can and can’t do, and your behaviors may change a little bit, so the odds that you are going to lose a significant amount of weight after that time period are definitely decreased,” said senior author John Scott, MD. “Therefore, the more weight you can lose during that honeymoon period, the better, because that effort will help establish a set point, in terms of where your steady weight is going to be further down the road.”

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