Weight loss from caloric restriction (i.e. dieting) tends to be modest and short-lived, whereas from bariatric surgeries such as Roux-en-Y gastric bypass (RYGB) is pronounced and generally sustained. The reasons behind these opposing outcomes between interventions remain unclear, but likely involve differential effects on gut-brain communication. Growth differentiation factor 15 (GDF15) is a ubiquitously-induced, centrally-acting, anorexigenic cytokine whose systemic levels are elevated under a variety of conditions associated with a negative energy balance, including in patients following RYGB. We therefore asked whether systemic and portal vein GDF15 levels differ between obese Zucker fatty rats that experienced similar weight loss from RYGB or from forced caloric restriction (CR). Compared with ad libitum fed (ALF) controls, body weight, visceral adiposity and food intake of RYGB and CR rats were markedly lower during the postoperative observation period. Both systemic and portal vein GDF15 levels in RYGB rats at postoperative day 28 were higher compared with ALF rats and particularly compared with CR rats. Further, systemic and portal vein GDF15 levels negatively correlated with body weight and food intake specifically in RYGB rats. These findings provide evidence that, unlike dieting, RYGB might achieve sustained weight loss and appetite suppression partly through increased GDF15 release from epithelial cells of the gastrointestinal tract.

热量限制（即节食）导致的体重减轻往往是适度和短暂的，而减肥手术（例如 Roux-en-Y 胃绕道术 (RYGB)）的体重减轻是显着的并且通常是持续的。干预之间这些相反结果背后的原因尚不清楚，但可能涉及对肠脑交流的不同影响。生长分化因子 15 (GDF15) 是一种普遍诱导的中枢作用的厌食细胞因子，其全身水平在与能量负平衡相关的各种条件下升高，包括在 RYGB 后的患者中。因此，我们询问全身和门静脉 GDF15 水平在经历了 RYGB 或强制热量限制 (CR) 类似体重减轻的肥胖 Zucker 脂肪大鼠之间是否不同。与随意喂食 (ALF) 对照相比，体重、RYGB和CR大鼠的内脏肥胖和摄食量在术后观察期内显着降低。RYGB 大鼠术后第 28 天全身和门静脉 GDF15 水平均高于 ALF 大鼠，尤其是与 CR 大鼠相比。此外，全身和门静脉 GDF15 水平与体重和食物摄入呈负相关，特别是在 RYGB 大鼠中。这些发现提供的证据表明，与节食不同，RYGB 可能部分通过增加胃肠道上皮细胞释放 GDF15 来实现持续的体重减轻和食欲抑制。RYGB 大鼠术后第 28 天全身和门静脉 GDF15 水平均高于 ALF 大鼠，尤其是与 CR 大鼠相比。此外，全身和门静脉 GDF15 水平与体重和食物摄入呈负相关，特别是在 RYGB 大鼠中。这些发现提供的证据表明，与节食不同，RYGB 可能部分通过增加胃肠道上皮细胞释放 GDF15 来实现持续的体重减轻和食欲抑制。RYGB 大鼠术后第 28 天全身和门静脉 GDF15 水平均高于 ALF 大鼠，尤其是与 CR 大鼠相比。此外，全身和门静脉 GDF15 水平与体重和食物摄入呈负相关，特别是在 RYGB 大鼠中。这些发现提供的证据表明，与节食不同，RYGB 可能部分通过增加胃肠道上皮细胞释放 GDF15 来实现持续的体重减轻和食欲抑制。