Should Marathon Runners Change Their Diet to Lose Weight?

Tuesday, June 30, 2015 | By Hal Higdon
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Should Marathon Runners Change Their Diet to Lose Weight?

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Twelve weeks into my marathon training program, I decided to switch to a high protein, low carbohydrate diet to lose weight. On Tuesday, I ran 4 miles at a slow pace. Wednesday (which was very hot) was slower yet. Thursday, it was cooler, so I ran 5 miles, also slow. During the week I lost 8 pounds! I plan to eat good carbs leading into the weekend long run, then try to watch my calorie count to maintain my weight loss, hoping that lighter will make me faster.


Eight pounds in less than a week by following a high-protein diet? I hate to disillusion you, but that is not a very healthy way to train. You lost those pounds, because a high-protein diet forces you to shed fluids, not a great idea during the summer when temperatures rise. Losing a few pounds because of a trick diet that forces you to sweat away fluids is easy; maintaining that weight loss is hard. I strongly advise that you get off that high protein diet and follow a diet that is 55% carbs, 30% fat and 15% protein. Most of those carbs also should be complex carbohydrates, the kind you find in fruits and vegetables and whole-wheat grains.

Rollercoastering between diets is never a good idea, whether while training for a marathon or not. Just as consistency in training works wonders, so too will consistency in eating. Carbo-loading should not come only before the weekend long runs, or before the race itself. Carbo-loading should be a permanent part of our lifestyles.

If still in doubt about diet, consult with a Registered Dietitian. RD’s are our sport’s number-one performance enhancers. 

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