Updated: February 8th, 2019

If you put on some winter weight prior to beginning your marathon plan, don’t despair! All of the long miles on the road, speed sessions, and hard hill climbs will have you back to fighting trim in no time.

In addition to hard training, the following dietary principles for marathoners will help you get lean while maintaining the energy balance needed for successfully marathon training.

Eliminate the Nonessentials

If you are trying to lose weight and get healthier while training for your next marathon, a first important step is to eliminate the non-essential foods and drinks from your diet that may be adding to your overall calories without boosting your fitness.


– Limit your intake of dessert foods (cake, ice cream, cookies, etc.), but not in the way you think.

If you have a sweet tooth, I recommend eating something light for dessert virtually every day rather than just once or twice a week. This way, you will satisfy a craving without going to Dairy Queen on your “dessert night” and downing 1000kcals at once of sugar and fat.

Try to have some dark chocolate when you hit that 2pm slump, a cookie at lunch, or some frozen yogurt after dinner when cravings attack instead of waiting until they build towards a confectionery binge.

You will satisfy your sweet tooth and maybe even lessen its strength by enjoying the foods you like on a regular basis rather than depriving yourself.

Soda and Sweetened Drinks

– Soda drinks only provide empty calories (45g of sugar in most 12oz soft drinks), no vitamins or minerals, and can even weaken bones due to the pantothenic acid many contain.

You don’t need soda as a regular additive to your diet, so try to limit these to rare occasions if you can. Diet sodas should be avoided as well due to the laxative effect certain artificial sweeteners can have on one’s stomach (especially runners).

Other drinks that contain largely empty calories with no nutritional use are sweetened coffee drinks, “juice” cocktails, alcoholic beverages, and sports drinks (outside of exercise situations where they may be needed).

Replace these drinks with water, 100% fruit juice, low-fat milks, and, if you do enjoy a drink on a regular basis, red wine- it contains many flavonoids, antioxidants, and resveratrol which may prevent certain diseases.

Time Your Carbohydrates

Marathoners need plenty of wholesome carbohydrates to fuel their training, but if you are trying to lose weight you won’t need to eat a pound of pasta each day.

The best time for a runner to consume starchy carbohydrates is within 3-4hrs prior to exercise and within 10min-2hrs after exercise.

If you run in the afternoon or evening, having some rice, bread, pasta, or potatoes at lunch will help you power through your evening run. After strenuous exercise, those carbs need to be replaced as well to restock glycogen stores for tomorrow’s training.

Try to consume the majority of your daily carbs within 2hrs of your running workout so these starches go to your muscles as fuel and not your belly as fat.

The rest of the day, eat your normal healthy diet of fruits, vegetables, lean proteins, and healthy fats to keep overall calories down to meet your weight loss goals.

Never cut more than 500kcals per day from your overall energy needs during marathon training! This will only invite illness or injury to curtail your plans for 26.2.

For instance, if you are 160lb runner who wants to lose a few pounds, your daily baseline calories needs may be around 2000kcals or so. Add to that number an eight mile run’s energy expenditure, and you are looking at a metabolic need of 2800kcals for the day to maintain your current weight.

Therefore, to lose roughly a pound per week you would need to eat 2300kcals per day; simple math for a complex metabolic effect.

Read here for more info about your metabolic needs and how to calculate your ideal caloric intake.

Eat Fat to Burn Fat

Healthy fat, that is. The type of dietary fat found in such foods as avocado, olive oil, coconut oil, most nut butters, and cold water fish are very beneficial to your overall health and performance as a runner.  

Lipids protect cells from damage, aid in recovery by carrying nutrients throughout the body, and can be used as long-distance running fuel; the best fats burn cleaner than the worst sugars when in marathon training.

Good fats will also increase feelings of satiety, a key to losing weight in general.

Dietary fat gets a bad rap because its very name implies that it is “bad for you”. This notion is a misconception, as fats are essential to good health.

The type of fat you want to avoid comes from cholesterol laden foods or those foods that are heavily processed with hydrogenated oils (trans fats). This would include fast food, fried meals, fatty cuts of beef or pork, and most packaged baked goods.

If you are training for a marathon while trying to lose weight, aim for a diet comprised of 50-60% Carbohydrate, 25-30% Healthy Fat, and 10-20% Quality Protein.

If you are looking for some easy to cook healthy recipes, have a look at Karine Losier’s Metabolic Cookbook.

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