You are what you eat, and that includes the things you feed your brain. Researchers at Harvard University have discovered that you can adjust serotonin, a brain chemical linked with depression, by varying the amount of carbohydrates in your diet. Not only that, when you get depressed, the brain triggers a craving for the carbohydrates capable of restoring the serotonin to normal. In other words, food can affect your mood, and your mood can influence which foods you choose.

Of all the nutritional options available, one is guaranteed to improve your health and enable you to live longer—eat less. Dr. Robert Good of the University of South Florida has conducted research that shows faster regeneration of liver tissue in rats with lower caloric intake. Evidently, illnesses stemming from an unbalanced immune system become easier to manage when calorie intake is limited. No one is certain of why this happens, although the most likely explanation may involve a reduction in lifetime exposure to free radicals (the supercharged atoms that can cause cellular damage and are thought to leave cells at risk for cancer and other diseases) and an increased desire to exercise. Whenever you reach a point during a meal when you’d like more, push the plate away and wait a few minutes instead of automatically reaching for second or third helpings. If you give your body time to digest, the hunger usually subsides, and you’ll be exactly where you need to be for optimal health.

By eating the right foods, you might be able to lessen your susceptibility to stress. Ultramarathoners are significantly more vulnerable to upper respiratory infection compared with moderate exercisers. Studies have revealed that when marathoners ingest 5 to 6 percent liquid carbohydrates, it reduces the stress-induced rise in cortisol. The same procedure blocks some of the immune system changes normally associated with excessive exercise. The natural antioxidants in whole foods have also been shown to counteract exercise-induced oxidative stress. While more research is needed, significant progress has been made in this area of study of special interest to elite athletes as well as weekend warriors.

God designed us to get peak performance from the best foods. When He gave us great food, however, he also gave us guidelines. Some foods provide the bursts of energy we need in the morning. Others help us slow down in the evening. Certain ones are great in small quantities and terrible by the plateful. Some bring out flavors, while others mask them. The options are many, but the aim is the same. Good nutrition is the process of balancing God’s great gifts for whole health.