Department of Nutrition, Gillings School of Global Public Health, School of Medicine; University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Obesity (Silver Spring). 2011 Jun;19(6):1109-17. doi: 10.1038/oby.2011.18. Epub 2011 Feb 17.
Obesity has reached epidemic proportions worldwide and reports estimate that American children consume up to 25% of calories from snacks. Several animal models of obesity exist, but studies are lacking that compare high-fat diets (HFD) traditionally used in rodent models of diet-induced obesity (DIO) to diets consisting of food regularly consumed by humans, including high-salt, high-fat, low-fiber, energy dense foods such as cookies, chips, and processed meats. To investigate the obesogenic and inflammatory consequences of a cafeteria diet (CAF) compared to a lard-based 45% HFD in rodent models, male Wistar rats were fed HFD, CAF or chow control diets for 15 weeks. Body weight increased dramatically and remained significantly elevated in CAF-fed rats compared to all other diets. Glucose- and insulin-tolerance tests revealed that hyperinsulinemia, hyperglycemia, and glucose intolerance were exaggerated in the CAF-fed rats compared to controls and HFD-fed rats. It is well-established that macrophages infiltrate metabolic tissues at the onset of weight gain and directly contribute to inflammation, insulin resistance, and obesity. Although both high fat diets resulted in increased adiposity and hepatosteatosis, CAF-fed rats displayed remarkable inflammation in white fat, brown fat and liver compared to HFD and controls. In sum, the CAF provided a robust model of human metabolic syndrome compared to traditional lard-based HFD, creating a phenotype of exaggerated obesity with glucose intolerance and inflammation. This model provides a unique platform to study the biochemical, genomic and physiological mechanisms of obesity and obesity-related disease states that are pandemic in western civilization today.
肥胖已在全球范围内达到流行程度，有报道估计，美国儿童从零食中摄入的热量高达 25%。目前存在几种肥胖动物模型，但缺乏将传统用于饮食诱导肥胖（DIO）啮齿动物模型的高脂肪饮食（HFD）与人类经常食用的食物（包括高盐、高脂肪、低纤维、高能量的食物，如饼干、薯片和加工肉类）进行比较的研究。为了研究 cafeteria 饮食（CAF）与传统的基于猪油的 45%HFD 在肥胖啮齿动物模型中的致肥胖和炎症后果，雄性 Wistar 大鼠分别用 HFD、CAF 或标准饮食（chow control diets）喂养 15 周。体重显著增加，并且 CAF 喂养的大鼠的体重与其他所有饮食相比仍显著升高。葡萄糖和胰岛素耐量试验表明，与对照组和 HFD 喂养的大鼠相比，CAF 喂养的大鼠表现出更严重的高胰岛素血症、高血糖和葡萄糖耐量异常。众所周知，巨噬细胞在体重增加时浸润代谢组织，并直接导致炎症、胰岛素抵抗和肥胖。虽然两种高脂肪饮食都导致肥胖和肝脂肪变性增加，但与 HFD 和对照组相比，CAF 喂养的大鼠的白色脂肪、棕色脂肪和肝脏表现出明显的炎症。总之，与传统的基于猪油的 HFD 相比，CAF 提供了一个强大的人类代谢综合征模型，导致葡萄糖不耐受和炎症的肥胖症表现明显加重。该模型为研究肥胖和肥胖相关疾病状态的生化、基因组和生理机制提供了一个独特的平台，这些疾病在当今西方文明中非常普遍。
