From RunningTimes.com, an article about eating like a Kenyan runner. That may be too many calories for regular runners.
Is Extreme Low-Fat Eating the Key to High Performance?
Research strongly suggests otherwise
By Jackie Dikos, R.D.
As featured in the Web Only issue of Running Times Magazine
As featured in the Web Only issue of Running Times Magazine
Kenyan dominance in distance running leads to the inevitable question of why they’re so good. Is it what they eat? If so, should we all eat like that to run our best?A 2004
study of elite Kenyan men during an intensive week-long training block found very low-fat diet patterns. In fact, their diet was documented to get just 13.4% of its calories from fat. (According to the USDA 2005 estimates, the average American eats nearly 2.5 times as much fat as the Kenyan runners who were studied.) The Kenyan study also found the men burned at least 600 more calories per day than they took in.
The Kenyan diet investigated was that of men. It’s a demonstration that a certain group of males can still achieve high levels of performance on very low-fat and low-energy diets, at least for a short time. (Again, the study tracked their diets for only a week and during an intensive training camp.) It’s likely, however, that the opposite holds true in other runners, especially women. Research produced at the University of Buffalo concluded that both male and female runners may have inadequate total calorie intake when eating a low-fat diet. It’s harder to meet high calorie requirements when dining on only low-fat options. For example, consider the Kenyan staple food ugali, which is a cornmeal paste (or more prosaically, glop)(see photo below)
The Kenyan diet investigated was that of men. It’s a demonstration that a certain group of males can still achieve high levels of performance on very low-fat and low-energy diets, at least for a short time. (Again, the study tracked their diets for only a week and during an intensive training camp.) It’s likely, however, that the opposite holds true in other runners, especially women. Research produced at the University of Buffalo concluded that both male and female runners may have inadequate total calorie intake when eating a low-fat diet. It’s harder to meet high calorie requirements when dining on only low-fat options. For example, consider the Kenyan staple food ugali, which is a cornmeal paste (or more prosaically, glop)(see photo below)
. It would take five packages of Trader Joe’s polenta to make up a 3,500-calorie runner’s diet. That’s a lot of polenta!
This study found essential fatty acids and minerals like zinc to be low in these runners. When overall energy intake is inadequate you run the risk of deficiencies. It also opens the window for increases in circulating stress hormones that can impair immune function.In a different study from the University of Buffalo, researchers found an association between low fat consumption in female runners and an increased risk of injury. The most common injuries were stress fractures, tendinitis, and iliotibial band troubles. The injured runners consumed both less overall fat and a lower percentage of total calories from fat than the less-injured runners in the study. There were also deficiencies in the fat-soluble vitamins K and E, which makes sense because fat is required to absorb these vitamins.
The study concluded that female runners consuming a low-fat diet are 2.5 times more likely to get injured; the study authors suggested considering consuming a diet consisting of 36% fat to avoid injury. That’s quite the opposite of the Kenyan diet.
Irregular menstrual function in females has long been associated with energy deficient and low-fat diets. A study last year found that such women also have a low serum vitamin E level. This low level leaves them more vulnerable to hemolysis, the abnormal breakdown of red blood cells, which could contribute to anemia in runners.
There are multiple studies showing a relationship between very low-fat diets and an inadequate total calorie intake, menstrual dysfunction, stress fractures, deficiencies and so forth. Yet the Kenyans studied somehow manage to maintain a state of homeostasis on the low fat diet. Is such a diet more gender-specific; does the female runner have greater physiologic demand? Or is it simply another example of how no two runners are the same? Factors like genetics and environment likely contribute to the Kenyans’ ability to withstand high performance demands on the low-fat and low-energy diet.
This study found essential fatty acids and minerals like zinc to be low in these runners. When overall energy intake is inadequate you run the risk of deficiencies. It also opens the window for increases in circulating stress hormones that can impair immune function.In a different study from the University of Buffalo, researchers found an association between low fat consumption in female runners and an increased risk of injury. The most common injuries were stress fractures, tendinitis, and iliotibial band troubles. The injured runners consumed both less overall fat and a lower percentage of total calories from fat than the less-injured runners in the study. There were also deficiencies in the fat-soluble vitamins K and E, which makes sense because fat is required to absorb these vitamins.
The study concluded that female runners consuming a low-fat diet are 2.5 times more likely to get injured; the study authors suggested considering consuming a diet consisting of 36% fat to avoid injury. That’s quite the opposite of the Kenyan diet.
Irregular menstrual function in females has long been associated with energy deficient and low-fat diets. A study last year found that such women also have a low serum vitamin E level. This low level leaves them more vulnerable to hemolysis, the abnormal breakdown of red blood cells, which could contribute to anemia in runners.
There are multiple studies showing a relationship between very low-fat diets and an inadequate total calorie intake, menstrual dysfunction, stress fractures, deficiencies and so forth. Yet the Kenyans studied somehow manage to maintain a state of homeostasis on the low fat diet. Is such a diet more gender-specific; does the female runner have greater physiologic demand? Or is it simply another example of how no two runners are the same? Factors like genetics and environment likely contribute to the Kenyans’ ability to withstand high performance demands on the low-fat and low-energy diet.
Are You a Calorie Cruncher?
Striving for 1,800 calories per day when every equation you calculate estimates calories at double that means you’re trying to train in a negative energy state. This sets you up for injuries, deficiencies, sickness, and substandard training. If you recognize you’re battling some of these issues, it’s time to bump up your calorie intake.
Do you remove the fat from just about everything you eat? Too much fat carries its downfalls, of course, but an appropriate amount of healthy fat is necessary. That 3,500-calorie diet of polenta could use a healthy 70 grams (20%) of fat. That may sound like a lot of fat, but 3,500 is also a lot of calories. A female runner struggling to maintain normal menstrual function might find a boost in dietary fat supports a normal cycle. That means a low-fat cereal might need to be prepared with 2% or even whole milk instead of nonfat; that a sandwich or salad could be topped with avocado; and that a nut-rich trail mix might be a good snack option.
There has to be balance in diet to have performance gains. Just because an extremely low-fat diet works for one segment of the running population doesn’t mean it works for all. Match your training with your diet, tune into physical signs of inadequacies, and find your nutritional balance.
Do you remove the fat from just about everything you eat? Too much fat carries its downfalls, of course, but an appropriate amount of healthy fat is necessary. That 3,500-calorie diet of polenta could use a healthy 70 grams (20%) of fat. That may sound like a lot of fat, but 3,500 is also a lot of calories. A female runner struggling to maintain normal menstrual function might find a boost in dietary fat supports a normal cycle. That means a low-fat cereal might need to be prepared with 2% or even whole milk instead of nonfat; that a sandwich or salad could be topped with avocado; and that a nut-rich trail mix might be a good snack option.
There has to be balance in diet to have performance gains. Just because an extremely low-fat diet works for one segment of the running population doesn’t mean it works for all. Match your training with your diet, tune into physical signs of inadequacies, and find your nutritional balance.
Jackie Dikos, R.D., is a 2:45 marathoner and mother of two. All of her Fueling the Runner articles can be found at http://runningtimes.com/fuel.
No comments:
Post a Comment