The Roux-en-Y Gastric Bypass (RYGB) procedure is known to be one of the most successful treatments for morbid obesity and Type 2 diabetes mellitus, and has been shown to decrease appetite, energy intake, body weight and glycemia both in the short and long term. A number of reports hypothesise that these changes may be driven, at least in part, by positive shifts in food preferences following surgery. However, findings are drawn from self-reported dietary intakes which are beset with measurement bias, thus precluding definite conclusions. The One Anastomosis Gastric Bypass (OAGB), or mini-gastric bypass, is another variation on the RYGB with one surgical connection (anastomoses) rather than two. Initial data has shown similar, or even slightly higher, weight loss and better resolution of diabetes post-surgery than the traditional RYGB, however as the technique was first reported in 2001 more long-term data is needed.