Sunday, December 12, 2010

How to Eat for Good Health; a summary of nutrition

As the biologist Dobzhansky said, nothing in biology makes sense except in the light of evolution. Without evolution, we have a world of facts that are true for no reason. This is awfully reminiscent of the image of good nutrition that has been prevalent over the last decades - "Eggs are good, no wait they're bad, actually they're OK, or maybe not", and so on. But since nutrition is a biological question, we can turn to evolution to give it some coherence.

Under this rationale, foods we have been eating for hundreds of thousands of years should be healthy for us - if they weren't before, we have at least had time to adapt to them. Newer foods could be fine or could be awful.

The most prevalent of these new foods are grains, refined/hydrogenated oils, refined sweeteners, dairy, and legumes. All of these have been shown to be problematic for at least a decent percentage of the population, and many people will benefit from eliminating all of them. The first three are particularly bad and should universally be avoided, with a few possible exceptions.

The modern diet and lifestyle cause a collection of diseases from obesity to high blood pressure to heart disease, together known as the metabolic syndrome. One of the symptoms of the metabolic syndrome is an inability to process carbohydrate effectively. So, while healthy populations exist that eat mostly carbohydrates, if you have these symptoms you may need to restrict carbs in general. Conversely, exercise increases carb tolerance and insulin sensitivity, so if you are active you may be able to handle more carbs. Carbs also may make you hungrier faster than protein or fat; I know this is true for me personally.

I have spent the last several months reading somewhat obsessively about nutrition, and have put together what seems to me to be a good compromise of health and permissiveness regarding diet.

----------

Eat
Animal products: Meat, fish, eggs, butter, cream, tallow, poultry, lard, etc.
Vegetables
Spices/Herbs
Healthy plant fats: Coconut oil, palm oil, olive oil, avocado oil, cocoa butter. Extra virgin is best.
Tubers: Sweet potatoes, turnips, beets, taro, etc. Potatoes are less good but OK; remove the skin.
Fruits

Eat sometimes
Tree nuts and drupes (walnuts, almonds, etc). Preferably soaked.
Fermented or sprouted legumes and non-gluten grains
White rice
Honey

Eat only if you tolerate it
Other dairy products, including milk and yogurt. Full fat is best.
Anything else not listed; consider the diets of your pre-industrial ancestors for guidance. Consider eliminating suspicious foods for a while and then reintroducing them.

Do Not Eat
Refined / concentrated sugar
Grains, especially gluten grains, especially wheat.
Refined vegetable / seed oils (soy, corn, sunflower, peanut, cottonseed, etc.)
Legumes

----------

Notes:
Meat: Just as we are healthier when we are treated well and eat our natural diet, so are the animals we use for food. Pastured, grass-fed cows give more nutritious meat and milk, with a better fat balance and much more vitamins. The same goes for chickens and their meat and eggs. Wild-caught food is also excellent. Ruminants may be marginally better than other meat sources. Organ meats and marrow are incredibly nutritious.

Fruit and sugars: Historically, we would have had limited access to fruit, and it would have been primarily during late summer and fall when we would be fattening up for the winter. It may be best to eat fruit seasonally and not overdo it. Use honey sparingly, but studies show it is not nearly as bad as refined sugar. Refined fructose is easily the worst sugar for your body. Next are sugars that contain it, such as sucrose.

Grains, nuts, and legumes: These foods tend to be high in antinutrients like phytic acid, which can leach minerals from the body. Grains also contain certain lectins that can bind to leptin receptors and likely impair the ability to feel satiated. Gluten, a particularly hardy lectin, damages the intestines even in non-celiacs and may make them permeable to other substances. Fermenting, sprouting or soaking improves nutrition and removes most of the problematic compounds in non-gluten grains and legumes. Many healthy pre-industrial cultures around the world do not consume grains, but those that do generally prepare them this way. White rice seems to have little or none of the problematic compounds in many grains, but still has low nutritive value.

Fats: You can essentially have unlimited saturated and monounsaturated fats. Polyunsaturated fats are the only kind of fat that you shouldn't go overboard on. These are composed primarily of omega-3 fats and omega-6 fats, and you want to get about an equal amount of both. Properly raised land animals have about this ratio, fish are higher in omega-3s and birds are lower. Almost all refined oils have a huge amount of omega-6 fats, far more than any natural food. This causes inflammation and heart disease, among many other problems. The average American diet is more like 15-to-1 in favor of omega-6s; this is why fish oil omega-3 supplements are so effective.

Vitamin D: Get it. Our bodies are adapted to being in the sun - a lack of it causes many of us to feel down in the winter. Lack of sun also combines with grain consumption to cause vitamin D deficiency in a large part of the population. Studies also indicate that D can cut your chance of getting the flu (and possibly some cancers) in half. Supplementation is probably a good idea - I take 2000 to 5000 IU per day. The RDA is way too low, a half hour in the sun will allow you to make as much as 10,000 IU.

Weight loss: Obesity is a disease generally caused by a poor quality diet, not by trying to eat too much. On a proper quality diet, obesity will generally reverse without a conscious effort to eat too little. Mild caloric restriction can help speed up this process, but may not be necessary. Taken too far, it is harmful and counterproductive.

Macronutrient ratios: You should be able to accomodate almost any macronutrient ratio within these guidelines. Experiment to see what works for you. I personally go quite heavy on fats, moderately high on protein, and somewhat low on carbs, but there's not really one ideal ratio.


Recommended Resources:
Videos:
Big Fat Fiasco: http://www.youtube.com/watch?v=exi7O1li_wA
Fat Head: http://www.hulu.com/fat-head (overlaps with the previous video, same guy)
Sugar: The Bitter Truth: http://www.youtube.com/watch?v=dBnniua6-oM

Blogs:
Whole Health Source: http://wholehealthsource.blogspot.com/ (this is my favorite resource, easily)
Cooling Inflammation: http://coolinginflammation.blogspot.com/
PaleoNu: http://www.paleonu.com/
Evolutionary Psychiatry: http://evolutionarypsychiatry.blogspot.com/
Hyperlipid: http://high-fat-nutrition.blogspot.com/
Something Awful Low Carb Megathread: http://forums.somethingawful.com/showthread.php?threadid=3359710

Books:
Good Calories, Bad Calories by Gary Taubes:
: http://www.amazon.com/dp/1400033462?tag=httpwwwmsue08-20

No comments:

Post a Comment