Everyone knows that eating only high fat food is unhealthy way down the road, but we don't really worry that eating a burger will hurt us by next week. Unfortunately, however, it turns out that a high fat diet damages our health (and our brain functioning) a lot sooner than we would like to think. In fact, new research shows that the effects are felt within only ten days. As far as I'm concerned, this was already shown conclusively in the film "Super Size Me," in which director Morgan Spurlock personally examined the effects of fast food on the human body. For one month, he ate only at McDonald's, ordering everything on the menu and "super-sizing" his order whenever asked. Right before our eyes, Spurlock began looking sicker and sicker.

But now Spurlock's experience has been substantiated by new research published online in the FASEB Journal, which shows that within fewer than ten days of eating a high-fat diet, rats had a decreased ability to exercise and experienced significant short-term memory loss. "Western diets are typically high in fat and are associated with long-term complications, such as obesity, diabetes, and heart failure, yet the short-term consequences of such diets have been given relatively little attention," said Andrew Murray, a co-author of the study from the University of Cambridge, in a press release.

The scientists studied rats that were fed a low-fat diet (7.5 percent of calories as fat) and rats that were fed a high-fat diet (55 percent of calories as fat). They found that after only four days, the muscles of the high-fat rats were less able to use oxygen to make the energy needed to exercise, causing their hearts to worker harder-and increase in size. After nine days on a high-fat diet, the rats took longer to complete a maze and made more mistakes in the process than their low-fat-diet counterparts. The researchers examined the rats' muscle cells and discovered increased levels of a protein called uncoupling protein 3, which made them less efficient at using oxygen to make the energy required for running.

So next time you go on a junk food binge, consider not only the effects you'll experience sometime in the vague future, but also how you'll feel and think just one week later.

Note: This research applies to eating high fat exclusively. This is unconnected to diets such as Dr. Richard Bernstein's who advocate a special combination of high protein and quality high fats (such as whole milk, and whole yogurt which, by the way, are lower carb than their low fat cousins). It's quite complicated and easy to get confused when discussing fat content.