Human nutrition is complex. There is no authoritative instruction manual for the operation of the human body. Many food choices are socially conditioned and only dimly related to biological necessity. The foods we ate when our digestive systems evolved are no longer available. All of the nutrients interact with each other in unforeseen ways. Improvement of one's personal nutrition is highly subjective.
In order to make sense of the subject, certain general principles are required to point the way:
I suppose other principles might work, but these are the three that have guided my experimentation. When in doubt, I tend to look back to humans eating a varied wild diet, rather than forward to industrialized food synthesis. When in doubt, I consider nutrients in food, rather than medicines or herbs, as the solution to any current unwellness. When in doubt, I experiment with my own nutritional requirements, rather than relying on statistical studies of groups of people and their longevity.
There is no substitute for reading a college-level nutrition textbook as an introduction to the basics of nutrition. Do not expect to understand everything written, but rather become acquainted with the terminology, the numerous nutrients and processes. When you do this, you are immunized against the simplistic thinking that informs many popular treatments of the subject. Furthermore, you learn which nutrients are dangerous in excess, and which are harmless in excess--invaluable information for the experiments to follow. There are biases in the standard dietetic treatment because of the inordinate amount of funding provided by agriculture and food processing corporations to the dietetic profession. Nevertheless, it is far more useful than most popular books on the subject.
Learn how to query PubMed on the internet. This compendium of the latest scientific research includes much nutrition research that explores the main threads of the subject. Do not expect the free abstracts to necessarily reveal the truth about anything, but rather to help you ask the questions.
It is impossible to have any meaningful control over your diet if you don't cook. Some of the most important nutrients are highly perishable fatty acids that occur in extremely small amounts, yet have vast repercussions in one's body. Commercial food preparers are unlikely to find it convenient to use fats that contain these highly perishable fatty acids in their products, so they will substitute fats with a longer "shelf life." Also, some of the most nutritious foods are simply not popular, they are never promoted, and few know how to prepare or enjoy them.
No self-respecting kid prefers a real tangerine to a tangerine-flavored LifeSaver. To suggest that a real tangerine is healthier is to promote a mind/body split that implies one's instincts are questionable, and have to be overruled by a nagging mind. This is a painful and an untenable way to live, never to be able to react without tedious mental reconsideration of one's simplest desires. The only possible solution is when a real tangerine tastes better than a tangerine-flavored LifeSaver. Why doesn't it?
If I have eaten nothing and then eat a good orange, I get a sensation of sweetness. If I eat candies, and then eat the same orange, I get a sensation of sourness. My senses are relative, but my sensations are absolute. By omitting the candy, I would have experienced no sourness. In common language, candies cause sweetness. In reality, candies cause sourness.
You may also follow the same analogy with fibrousness. Refined food causes fibrousness, a sensation which does not occur if one eats unrefined foods exclusively.
This aesthetic leads to greater complexity of experience. One excludes the stridently artificial, in this case the manufactured and denuded, in order to experience more pleasure. You must never eat something because "it is good for you." You must eat something you want, or your body is not able to assimilate it with enthusiasm and joy. The cliche "A spoonful of sugar helps the medicine go down" should really be "Sugar is being used to disguise the fact that I don't want to eat this unappetizing thing."
Cravings are usually presented as a desire for the forbidden, a desire that must be curbed. I prefer to understand cravings as great opportunities for understanding and improving my nutrition.
At one point I was eating a very low fat diet, and got a craving for ice cream that persisted for weeks. I reasoned that the main nutrients in ice cream were butterfat, calcium, and carbohydrates. The butterfat is high in saturated fat, and since that was definitely a nutrient in short supply in my diet (although many would say it should be excluded and causes heart disease), I tried to see how much butter I needed to eat in order to have no desire for ice cream. The amount of saturated fat turned out to be quite moderate, and I proved to myself that I did need a certain amount of saturated fat in my diet and I discovered how much.
Sometimes the idea works in reverse. I tried to get enough Vitamin C from eating large amounts of red bell peppers. Even though I later discovered I was still deficient in Vitamin C, I got sick of eating the peppers and was never sure if a rash that broke out on my hands was caused by them. Finally I realized I just didn't want the peppers and resumed taking Vitamin C pills. It was not necessary to pursue the question of what I had too much of in the peppers. The point is that these direct experiences of wanting to eat something or not wanting to eat something are more important than theoretical considerations for getting at the truth of nutrition.
A small patch of dry skin, a bruise, a fingernail irregularity such as hangnails, muscle aches unrelated to exertion--all are grist for the mill. The more insignificant the better, these can be the first indication of a nutritional deficiency or excess. Serious illness is not helpful here, because immediate therapy is required, there is no leisure to experiment with various nutrients, and it is too late. But minor symptoms, if noted and pursued, can usually be linked to a nutrient deficiency or excess which can be corrected before any serious consequences arise.
Find the foods that are easily obtainable, that you love to eat, that are the richest sources of the nutrient you are testing. Find out how much you can eat of these foods without tiring of them, and then try a supplement pill of the nutrient you are testing. If you feel worse or no different with the supplementation, you can be pretty sure your dietary source is sufficient. If you notice you feel better with the supplement, or a symptom goes away with the supplement, you know the food source is simply not enough for your personal requirement, and that you will have to supplement that nutrient.
Human nutrition is a difficult and confusing subject. Don't make it even more difficult. If you think you might need some more B vitamins, don't take Super-B with Ginkgo Biloba and St. John's Wort. If it works for a while, but then another symptom shows up, how will you know which nutrients were essential and which might be excessive and causing problems? Try to simplify your experiments. If you do feel better after taking a complicated formula, plan to try to figure out exactly what you need. When you know you need something specific, that part of your nutrition puzzle is settled and you can look to those parts you haven't figured out yet. Nevertheless, several times I have been totally without a clue, and have started taking a huge multivitamin to see if anything happens. If I notice an improvement, I then get as many of the nutrients as individual pills as I need to see what was actually the important nutrient.
When the nutrients come from supplements, you want to try to get the minimum that fulfills the requirement. Understand that you may need a huge amount to fulfill a serious deficiency, but after the deficiency is gone, you need just the amount that covers day-to-day loss, which may be very small indeed. When you discover a nutrient which makes you feel better, or makes a symptom go away, you need to retest at least once to see if you can get away with less. It is possible to get too much of a nutrient, and it has been noticed that the symptoms of too much are sometimes the same as the symptoms of too little (usually explained as some limiting step in the chemistry). The advantage of a varied diet of real food is that it contains most of the nutrients you need and will almost never have too much of any particular nutrient.
Sometimes you will feel better because of the placebo effect, in which faith in a useless remedy provides temporary euphoria. Clues that the placebo effect is operating are:
I was quite resistant to this idea, but it turned out to be very helpful. You simply pretend to be convinced your moods are caused not by external events or psychological or spiritual factors, but solely by nutrition. You are then able to feel effects primarily of the long chain omega-3 fatty acids in fish (these fatty acids comprise a large percentage of your brain and nervous system), some of the B vitamins, chromium, and perhaps other nutrients. Our society does not recognize food as a cause of spiritual or psychological malaise, so it is necessary to actively look for the connection--otherwise it is invisible due to social conditioning. Actually, few people seem to even feel that their physical condition is directly related to their nutrition. Although intellectually admitting the idea, few respond to unwellness with any serious nutritional questions.
It is not healthier to have a bowl of zucchini than to have a cheeseburger. If you can get a list of nutrients in the two foods, while the cheeseburger is loaded with nutrients of all kinds, the zucchini has almost nothing but water. I like zucchini, I eat it frequently, and it is a fine and enjoyable addition to my diet. But understand that the denigration of cheeseburgers is aimed toward that segment of the public that eats nothing but cheeseburgers! For them, zucchini is healthy. For you, maybe you need a cheeseburger, or at least some densely nutritious food that has some chance of satisfying your requirement for protein, B vitamins, calcium, iron, and zinc.
Furthermore, I urge you to try to drop any nutritional ideology. The discoveries you make in experimenting with your nutritional requirements will surprise you whether they reinforce your customary eating patterns or contradict them. You will see certain complex ecological connections which cannot be expressed as ideological constructs, and you do not want to be blinded by pre-conceived notions.
Nutrition takes time. It takes time for every animal to get its food, prepare it, eat it, and clean up. We suffer from food inflation, in which food is plentiful, quick and easy to get, but unfortunately some necessary nutrients are in short supply. The most common nutrients are puffed up and extruded by agribusiness, and that's fine; but you will probably discover, as I did, that the nutrients that are lacking are harder to get, and that is why they are lacking! They are the nutrients that don't ship well, that don't stand up under storage, that are overlooked in modern farming, that aren't released in modern preparation methods, and that are in foods that don't yield extravagant profits. It takes extra effort to seek them out and dig them up off the beaten supermarket path.
You are finished with your nutrition exercise when: