Between October 2013 and July 2014, six healthy, middle-aged men reported to Temple University Hospital in north Philadelphia. For seven days, researchers confined each subject to his hospital bed and told him to select breakfast, lunch, and dinner, along with three daily snacks, from the hospital menu containing typical American cuisine: eggs, fried chicken, hamburgers, French fries, etc. The intake totaled a whopping 6,000 calories—about 2.5 times the men’s normal diet.
The high-calorie diet worked as planned, with participants already showing signs of insulin resistance by day two. By the end of the week, the men showed a 50-percent decrease in their insulin-stimulated glucose uptake. (They also gained an average of 3.5 kg, all of it fat.) Then it became a question of what was causing the problem. Fatty acid levels didn’t go up; in fact, they went down slightly. A survey of five proinflammatory cytokines also ruled out inflammation as a cause. And there were no signs of increased ER stress in biopsied adipose tissue. “So I’m pretty sure that none of these three had anything to do with this massive insulin resistance,” Boden says. “What we did find was that oxidative stress went up. And not only did it go up, but it went up exactly at the same rate as insulin resistance went up.”
Here's the paper:-