A high-fat diet rich in corn oil reduces spontaneous locomotor activity and induces insulin resistance in mice

J Nutr Biochem. 2015 Apr;26(4):319-26. doi: 10.1016/j.jnutbio.2014.11.004. Epub 2014 Dec 15.


Over the last few decades, polyunsaturated fatty acid (PUFA), especially n-6 PUFA, and monounsaturated fatty acid content in 'Western diets' has increased manyfold. Such a dietary shift also parallels rising sedentary behavior and diabetes in the Western world. We queried if a shift in dietary fats could be linked to physical inactivity and insulin insensitivity in mice. Eight-week old female C57/Bl6 mice were fed either high-fat (HF) diets [40% energy corn oil (CO) or isocaloric olive oil (OO) diets] or chow (n=10/group) for 6 weeks, followed by estimation of spontaneous locomotor activity, body composition and in vivo metabolic outcomes. Although lean mass and resting energy expenditure stayed similar in both OO- and CO-fed mice, only CO-fed mice demonstrated reduced spontaneous locomotor activity. Such depressed activity in CO-fed mice was accompanied by a lower respiratory ratio, hyperinsulinemia and impaired glucose disposal following intraperitoneal glucose tolerance and insulin tolerance tests compared to OO-fed mice. Unlike the liver, where both HF diets increased expression of fat oxidation genes like PPARs, the skeletal muscle of CO-fed mice failed to up-regulate such genes, thereby supporting the metabolic insufficiencies observed in these mice. In summary, this study demonstrates a specific contribution of n-6 PUFA-rich oils like CO to the loss of spontaneous physical activity and insulin sensitivity in mice. If these data hold true for humans, this study could provide a novel link between recent increases in dietary n-6 PUFA to sedentary behavior and the development of insulin resistance in the Western world.

Keywords: Corn oil; Diabetes; Exercise; Insulin resistance; Locomotor activity; MUFA; Polyunsaturated fatty acids; n-6 PUFA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Corn Oil / administration & dosage
  • Corn Oil / adverse effects*
  • Diet, High-Fat / adverse effects*
  • Dietary Fats / administration & dosage
  • Dietary Fats / adverse effects*
  • Fatty Acids, Nonesterified / blood
  • Fatty Acids, Omega-6 / administration & dosage
  • Fatty Acids, Omega-6 / adverse effects
  • Female
  • Glucose Tolerance Test
  • Hyperinsulinism / blood
  • Insulin / blood
  • Insulin Resistance*
  • Mice
  • Mice, Inbred C57BL
  • Motor Activity*
  • Olive Oil / administration & dosage
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Triglycerides / blood


  • Dietary Fats
  • Fatty Acids, Nonesterified
  • Fatty Acids, Omega-6
  • Insulin
  • Olive Oil
  • RNA, Messenger
  • Triglycerides
  • Corn Oil