title: Dietary intake of medium- and long-chain triacylglycerols ameliorates insulin resistance in rats fed a high-fat diet.
abstract: OBJECTIVE
  Excessive accumulation of visceral fat is strongly associated with insulin resistance. The present investigation examined the effects of dietary intake of medium- and long-chain triacylglycerols (MLCTs), which have been shown to induce significantly lower visceral fat accumulation in rats and humans, on high-fat diet-induced obesity and insulin resistance in rats. These effects were then compared with those observed in long-chain triacylglycerol (LCT)-fed rats.
  
  
  METHODS
  After an 8-wk feeding of a high-fat diet, which induced severe whole-body insulin resistance, male Sprague-Dawley rats were fed a standard diet containing LCTs or MLCTs for 6 wk. After the dietary treatment, an oral glucose tolerance test was performed.
  
  
  RESULTS
  Although body weight and total intra-abdominal fat mass did not differ between the two groups, mesenteric fat weight in the MLCT-fed group was significantly lower than that in the LCT group (P < 0.05). The increase in plasma insulin concentrations, but not in glucose, after glucose administration (area under the curve) was significantly smaller in the MLCT group than in the LCT group (P < 0.01) and was significantly associated with mesenteric fat weight (P < 0.05). MLCT-fed rats had significantly higher plasma adiponectin concentrations compared with LCT rats (P < 0.05). Adiponectin concentrations were negatively correlated with the area under the curve for plasma insulin (P < 0.05) and tended to be inversely related to mesenteric fat weight (P = 0.08).
  
  
  CONCLUSIONS
  These results suggest that dietary intake of MLCTs may improve insulin resistance in rats fed a high-fat diet, at least in part through increased adiponectin concentrations caused by a lower mesenteric fat mass.
authors.affiliation: Central Research Laboratory, The Nisshin OilliO Group, Ltd., Yokosuka City, Kanagawa Prefecture, Japan. s-terada@nisshin-oillio.com
authors.forename: Shin
authors.initials: S
authors.lastname: Terada
authors.forename: Sayuri
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Seiji
authors.initials: S
authors.lastname: Sekine
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Aoyama
mesh_terms: D052242:Adiponectin / Q000097:blood*; D050154:Adiposity; D000818:Animals; D001835:Body Weight; D059305:Diet, High-Fat / Q000009:adverse effects*; D004041:Dietary Fats / Q000627:therapeutic use*; D005227:Fatty Acids / Q000032:analysis / Q000737:chemistry; D007333:Insulin Resistance; D050152:Intra-Abdominal Fat / Q000473:pathology; D008297:Male; D050177:Overweight / Q000097:blood / Q000178:diet therapy / Q000378:metabolism / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014280:Triglycerides / Q000737:chemistry / Q000627:therapeutic use*
chemical_list: D052242:Adiponectin; C499920:Adipoq protein, rat; D004041:Dietary Fats; D005227:Fatty Acids; D014280:Triglycerides