Bariatric Surgery Recipients Require Dietary Discipline

Dr. Noora Kanerva from the University of Gothenburg, Gothenburg, Sweden, and colleagues analyzed data from the Swedish Obesity Study (SOS), a more than 30-year investigation comparing bariatric surgery with conventional treatments for obesity. In particular, they were interested in learning whether the short-term dietary changes a person made after bariatric surgery (i.e. in the first six months) might be predictive of the long-term (10 years) success of the procedures. In part, their interest stemmed from the observation that about “20-30 percent of obese patients do not achieve successful weight outcomes after bariatric surgery.” Their concept was that the ability to adapt to the changes necessary for weight loss after bariatric surgery would be predictive of long-term weight loss success.

Individuals’ weight, height and waist circumference were measured at periodic interview sessions, and food intake and activity levels were self-reported. Data from about 2,000 subjects of the SOS were included in this analysis. Criteria for participation included a BMI of over 34 for men and over 38 for women and ages of 37-60 years. Baseline data were obtained four weeks prior to surgery.

Changes from baseline values were assessed at six months and periodically until ten years post-surgery. Based on changes from baseline, the respondents’ energy intake reductions were divided into three groups: group 1 had the smallest reduction (300 kcal), group 2 an intermediate reduction, and group 3 the largest reduction (2500 kcal).

They concluded that early weight loss was indeed predictive of the long-term success of surgery-induced reduction. While their conclusion is logical, there are weaknesses in the design of this study. First, the type of surgery varied among individuals — most had had vertical gastric banding procedures, while others had another form of gastric banding and yet a third group had gastric bypass surgery. It isn’t clear whether the success at ten years was influenced by the type of surgery as well as by the early reduction in energy intake. Further, surgical procedures change with time — for example, more recently the proportion of bariatric procedures performed via laparoscope is much higher than it was when this study began.

http://www.acsh.org/news/2017/07/25/even-bariatric-surgery-recipients-require-dietary-discipline-11599