Healthy eating is easy for me. I like the taste of veggies, and after just a few fattening meals of meat and fried foods I get a nauseous feeling at the idea of having more without a break. This disposition seems to be at least partially genetic, having to do with everything from metabolism to taste buds. Still, even I have to admit: all things being equal, cream-filled doughnuts are more appetizing than raw broccoli, and a half-pound burger makes my mouth water more readily than a salad. Why would this be, when the salad has so many nutrients needed by the body? Ought I not to crave the super-food with the much wider variety of necessary substances?Well, it seems not. We do develop certain cravings when particularly deficient in nutrients, but for the most part evolution has had to concern itself with survival over nutrition. A good level of magnesium is a luxury of the living, and an animal that opted to eat a light, nutritious meal rather than a more calorie-rich one could easily come to regret that decision the next day. Evolution really does believe that it’s better to have too much than too little.This was once the source of our sugar fixation.Remember that it’s only in the last few thousand years that our lifespans have becoming reliably long enough for chronic deficiencies to even really become a problem; outside of the most extreme cases of malnutrition, it’s difficult to die from a lack of vitamins and minerals. Rather, low levels of such things simply hurt overall health levels over time, which only becomes an issue if you are likely to live long enough to experience those problems. Fat, protein, and carbohydrates all have much more direct benefit, and can be put to use for such vital activities as running, carrying and, yes, even thinking.The brain is one of the body’s biggest calorie-sinks and a lack of input can cause sluggishness of the brain right along with the body. When split-second reflexes can be as important as top-speed, it’s important to stay fueled up. Evolution made us neurotic about filling the tank with high-octane foods that pack the most energy per gram swallowed. The abundance offered by agriculture and modern science has had neither the time nor the lethality necessary to change our genetic predispositions.Additionally, don’t assume that all foods that are “bad” for you can’t be good for you, too. Red meat is packed with cholesterol and all sorts of artery-clogging substances, but it’s just as rich in vitamins and minerals stolen from whatever animal you’re consuming. Sweet sugars often come packed right along with Vitamin C and other useful molecules. It’s only recently that we’ve had the ability to isolate the “bad” things from the good, and evolution has had no real time to adapt.