This is the question someone asked me the other day in regards to the good results I've had on low-carb. Beyond just satisfying your curiosity, having a lattice work of mental models, as Charlie Munger puts it, can save you a lot of trouble. Without mental models of (in this case) human digestion, evolution, nutrition research, journalism, medical education, and even politics, all I'd have is just something that works for acid reflux. A little knowledge is a dangerous thing. Something that works might only work in certain situations, could be unpredictable, could have unintended consequences, or could just be a placebo effect. Knowing how something works reduces the danger. As Munger's partner Warren Buffett put it, "Risk comes from not knowing what you're doing." Yet how often are people overconfident when they only know a thing or two? The web is full of bros who cut down on the beer and pizza, got some exercise and lost 40 pounds--and you can, too!
Do-it-yourself health. Low-carb, mostly evolutionary.