What should a runner eat? The Internet, you won't be surprised to learn, has every conceivable answer. From, whatever you want to nothing (aka, intermittent fasting).
My latest take on diet is encapsulated by one of Dave MacLeod's vlogs*: 20 years of depression resolved.
On the surface, the very premise of this video seems like a click-bait mess. Dave's telling the world that he cured himself of depression by making one change: going keto! So there you go, if you want to cure your depression you should stop eating carbs the rest will take care of itself.
Thankfully, that message is the furthest thing from Dave's point. Yes, it's true he changed to a ketogenic diet and it appears to have positively impacted his mental health. But Dave goes to great lengths to make it clear that he lacks evidence to definitively link the two. Also, Dave's choice of ketogenic diet is optimized for his sport: rock climbing. His goal of starting a low carb diet was to cut body fat percentage, which on its surface makes sense. Having less fat to haul up a rock face, and more muscle to help you do so, is an obvious advantage.
I'm not wrestling with depression, nor am I interested in optimizing my body to be in climbing shape. Yet, I still find quite a bit of wisdom in Dave's video. My main takeaway: the answer to what should a runner eat? is to turn to science.
I mean 'science' in at least two senses. First, Dave promotes the idea of running experiments on yourself. This of course, is at the heart of science. Make a change, observe the outcome, document the results, repeat.
For Dave, the experiment was following a ketogenic diet. For me, it's been doing things like focusing on consuming more complex carbs, varying meal times before a run and starting the day with a protein shake. Some of these experiments have had promising results (carbs = good!), others not so much (I'm looking at you, morning protein shake). I strive not to think of these experiments in terms of success or failure; just as more data.
Of course, you need not rely solely on self experimentation. That's the other way science saves the day: with a bit of digging, you can find papers and other resources that have tackled topics you're interested. As a runner, what role do carbs play? A huge one. Which is better for runners, a low or high GI diet? From a performance perspective, it doesn't matter. Should I be avoiding gluten? No. Of course, no one study should be taken as gospel. But they are a far better option than taking some YouTube'ers word for it. In short: Look for evidence, make informed decisions.
I've been collecting up notable articles and papers here:
It's been empowering to look at diet as a journey, rather than a set of must-do-rules.
So what should a runner eat? I'm still not sure, but I'm having fun figuring it out.
Check out Dave's video for inspiration:
*Side note: Dave's vlogs are terrific. He frequently takes questions which you'd expect a flippant response to, and provides a meaningful and insightful answer. I'm not a rock climber, but I love all the wisdom he drops.