New HRB funded study confirms hunger reduction behind success of obesity surgery

Roux-en-Y gastric bypass and Sleeve gastrectomy does not affect food preferences when assessed by an ad libitum buffet meal

Nielsen, M.S., Christensen, B.J., Ritz, C. et al. OBES SURG (2017). doi:10.1007/s11695-017-2678-6


Mette S. Nielsen, Bodil J. Christensen, Christian Ritz, Simone Rasmussen, Thea T. Hansen, Wender L. P. Bredie, Carel W. le Roux, Anders Sjödin, Julie B. Schmidt

Background Roux-en-Y gastric bypass (RYGB) and Sleeve gastrectomy (SG) lead to a reduction in energy intake. It is uncertain whether this reduction is simply due to eating smaller portions or if surgery changes food preferences towards less energy-dense food. Previous results rely on verbal reports, which may be prone to recall bias and underestimation of especially unhealthy foods.

Methods Using an ad libitum buffet meal targeting direct behavior, we investigated if RYGB and SG surgery leads to changes in food preferences. In addition, we assessed food preferences by a picture display test to explore differences between a method relying on verbal report and a method assessing direct behavior.

Results Forty-one subjects (BMI: 45.0±6.8kg/m2) completed a visit pre and 6 months post RYGB (n=31) and SG (n=10). Mean BMI decreased with 11.7±0.6 kg/m2 and total energy intake at the buffet meal with 54% (4491±208kJ vs. 2083±208kJ, P<0.001), respectively. However, relative energy intake from the following food categories: high-fat, low-fat, sweet, savory, high-fat-savory, high-fat-sweet, low-fat-savory and low-fat-sweet, as well as energy density did not change following surgery (all P≥0.18). In contrast, the picture display test showed that food from the low-fat-savory group was chosen more often post-surgery (34±8% vs. 65±9%, P=0.02).

Conclusion The reduction in energy intake after RYGB and SG surgery and the subsequent weight loss seems to be primarily related to a reduction in portion sizes and not by changes in food preferences towards less energy-dense foods. These results underline the necessity of investigating eating behavior by targeting direct behavior.

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