Solid food was replaced with Vanilla Ensure (Abbott, Lake Forest, IL) for post-operative recovery starting 24 hours prior to surgery and for 72 hours after surgery. All animals were fasted overnight but had ad libitum access to water. SG and pair-fed sham, or ad-lib sham surgeries were performed as previously described [5 (link),10 ]. All animals were started on Purina diet 5008 72 hours after surgery. SG and ad-lib sham rats have unlimited access to food. Pair-fed sham rats’ food intake was restricted to match the daily food intake of SG rats. Pair-fed sham rats were given the same amount of daily food consumed on average by the SG rats for the same postoperative day throughout the study period. For example, if the average food intake of obese SG rats was 15g on postoperative day #15, all pair-fed sham rats would receive only 15 g of food for their respective postoperative day 15. This creates a pair-fed group that is weight-matched and food-intake matched to the SG group.