It is a cliché saying by now, but still holds true, "we are what we eat." When we take the time to notice how we feel after meals or snacks, we may notice that certain foods give us lasting energy and others completely zap our strength and leave us feeling less than brilliant. A recent study by researchers at Oxford University demonstrated that a high-fat diet can reduce not only our endurance, but can also impair our memory and mental function as well.
Prior studies have shown that long-term consequences of a high-fat diet, that is a diet with approximately 50% or more of calories coming from fat, include obesity, diabetes, and heart disease. The new research suggests that even a temporary stint of eating a high-fat diet can lead to short-term memory loss and decreased endurance. Researchers studied rats and fed them a lowfat (7.5% fat) diet for two months and trained them to run on a treadmill, and master a maze that led to a sweet treat at the end. After the two-month trial, half the rats where switched to a high-fat (55% fat) diet (the others stayed on the 7.5% fat diet). Five days after the diet switch, the rats were retested. Compared to the low-fat group, the rats on the high-fat diet ran 30 percent less on the treadmill and by day 9 that number increased to 50 percent lower performance on the treadmill. The rats on the high fat diet also took longer to complete the maze and made more mistakes than the rats on the low-fat diet.
There are a few things that happen physiologically when we eat a high-fat diet.
Fatty foods can trigger insulin resistance. Insulin resistance makes it more difficult for the body to use glucose, which is the preferred food source for our brains. High-fat diets can also reduce muscle and liver glycogen concentrations, which will lead to a reduction in physical performance.
Though there is no perfect "one size fits all" diet for everyone, most of us would be well served to focus on a balance of whole grains, fresh fruits and vegetables, lean meat and poultry, low-fat dairy products and fat that comes from sources like nuts and seeds, olive oil, and deep sea, cold-water fish. Decreasing our intake of saturated fat and eliminating trans-fat from our diets would be one place to start.
This is definitely great food for thought. Think about this information next time you consider a weekend of indulging in pizza, hot dogs, French fries, and cheeseburgers; especially if you know you have to perform either at work or at school on Monday.
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