Matt Fitzgerald’s book The Endurance Diet is probably the best book on basic nutrition for endurance athletes.
Though Matt has written other books on fueling races and workouts, and maintaining an ideal weight for running, his field research of elite athletes around the world finally put together all the pieces of his knowledge into a system to help you assemble a sustainable, repeatable training diet that will effectively fuel your workout while maintaining a healthy weight and lifestyle.
The book goes into more useful detail on what these are about, but Fitzgerald says all elite athletes eat successfully around key core habits: To eat a healthy variety of foods, provided they are high quality, to eat a lot of carbs, get enough to eat, and to eat “individually”, aka eat the diet that works for you rather than eat someone else’s prescribed diet. Matt emphasizes that while he says ‘eat like the elites’, the end goal is to realize how the elites’ fundamental habits benefit them, then to try and adopt some of their common habits for your own benefit.
Matt also creates a system to assess your diet called the Diet Quality Score. Every item you eat is scrutinized for quality, assigned to a category, and given a positive or negative score. Good foods are scored +1 or +2 per serving, and the system observes a law of diminishing returns: Eat too much of a good food and the points additional servings are worth drop to 0 or even negative numbers. Bad foods get a -1 or -2 per serving.
A perfect Diet Quality Score (DQS) is 35, but Matt says that shouldn’t be the goal, that even top elite athletes typically only score in the low 20’s. He doesn’t offer a tiered scale on what DQS is good, okay, bad, etc, but it’s safe to say that you can probably tell if your’s is good or bad once you’ve assessed your diet.
My DQS rule: Anything in positive double digits (10+) is okay, and if possible you want to get to 20. If you’re in the negatives, you have some serious work to do. Someone whose diet needs an overhaul probably should aim first to consistently get above 10, and once that’s sustainably repeatable over a few consecutive months, then try to improve to 20.
Of course, my overall general nutrition rule is that if your diet needs substantial improvement, you should focus on one habit at a time: Try to improve one dish or one meal at a time, aka focus only on eating a super healthy lunch, to get that right every single day, and then do whatever you want the rest of the day. After that becomes a firm habit, then try to fix one other aspect of your diet, and repeat as needed. But I digress.
Personally, I’m juggling a lot of personal needs when I’m trying to plan out my diet:
- Obviously, I need to eat enough to fuel my training.
- Obviously, I need to make sure not to eat so much that I gain weight.
- Obviously, I want my diet to be clean and built around whole foods rather than processed foods, as much as reasonably possible.
- The diet has to be as affordable and inexpensive as possible, without sacrificing quality.
- The diet needs to fit my schedule and capabilities for preparing food.
- It has to be consistently repeatable, with foods that are relatively easy to prepare, or I won’t be able to stick to it.
- My diet needs enough protein to rebuild muscle, about 1g per pound of lean body mass at minimum.
- My diet needs to have the right amount of potassium (3500-5000mg per day). If it I eat too little, then (among many other health problems) I won’t be able to sleep well. If I eat too much potassium (6000+mg), I’ll probably destroy my kidneys.
- And, of course, the foods I eat have to be satisfying. If I’m hungry right after eating, that defeats the purpose of eating. And I won’t be able to sleep well.
Using other planning methods, it can be a substantial pain to figure out a diet that meets all of these needs. You can map out a perfect diet, and then discover you’re way short on potassium, or the foods are too hard to find or cost too much per week, or preparing the needed food is too much of a hassle to be a repeatable process, and so on.
The Diet Quality Score, however, cuts a lot of the crap. You can use it to map out a workable diet using foods you consider accessible and easy to eat/add. And often when you crunch the numbers everything kind of works out with every other category: You get enough calories, enough protein, enough potassium, without adding too much other crap.
If you run a lot, or do any other sort of endurance exercise, or even are some other type of competitive athlete… I would definitely recommend getting a copy of The Endurance Diet and not just reading it, but using the process it outlines to help you figure out a diet that will clean up your nutrition, create an improved, sustainable diet plan, and keep you moving ahead.