Disease Proof

High-Fat Diets Screw Up Physical Performance in Rats!

Poor little lab rats! New findings in the FASEB Journal show consuming a high-fat diet significantly reduces physical endurance—and memory—in rats. After nine days, rats on a high-fat diet could only run half the distance of rats eating a low-fat diet.

On the fifth day of the high-fat diet (the first day back on the treadmill), the rats were already running 30 per cent less far than those remaining on the low-fat diet. By the ninth day, the last of the experiment, they were running 50 per cent less far.

The rats on the high-fat diet were also making mistakes sooner in the maze task, suggesting that their cognitive abilities were also being affected by their diet. The number of correct decisions before making a mistake dropped from over six to an average of 5 to 5.5.

The researchers also investigated what metabolic changes the high-fat diet was inducing in the rats. They found increased levels of a specific protein called the 'uncoupling protein' in the muscle and heart cells of rats on the high-fat diet. This protein 'uncouples' the process of burning food stuffs for energy in the cells, reducing the efficiency of the heart and muscles. This could at least partly explain the reduction in treadmill running seen in the rats.

The rats that were fed a high fat diet and had to run on the treadmill also had a significantly bigger heart after nine days, suggesting the heart had to increase in size to pump more blood around the body and get more oxygen to the muscles.

High-fat diets will jack you up! Back in April, a study showed low-fat diets improve people’s health after weight-loss by improving blood vessel function much better than fatty diets.

Via EurekAlert!

Image credit: Trek Nature

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Comments (1) Read through and enter the discussion with the form at the end
Steve - August 12, 2009 9:36 AM

Hi Gerry

Pick up a couple of sports nutrition books at the library and chances are good they will discuss high fat diets.

I suspect it would be a sports nutritionists dream to find a high fat diet that improved athletic performance (cyclists and marathon runners would not bonk, and therefore not need to eat food mid race).

However, the results always seem to be the same. At high exercise intensities you MUST burn carbs (fats cannot be burned anaerobically), so I suspect the results will always be poor.

Cheers, Steve

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