SORRY THAT THIS IS SO LONG! For part of my degree I took some nutrition classes and then focused on the PALEO diet. This was one of my better reports on why the FDA "Food Pyramid" is fucking bullshit, and why carbohydrates aren't always good for you.
Macronutrients: Proteins, Fats and Carbohydrates
by Kylie Boyle
Proteins are chains of smaller molecules called amino acids. Proteins are what compose our muscles and give our bones tensile strength and they include enzymes that make all the chemical reactions in our bodies possible. Generally, the body is constantly turning over proteins and re-cycling the amino acids to make new proteins for both structural and enzymatic purposes. Some of the amino acids (aas) will get used up in this turnover process, so we must have a certain amount of our calories come from protein to replenish these aas or we will literally waste away and die. There are 20 aas used by the body to synthesize new proteins, and we must have 8 of them to avoid deficiency. These are the essential amino acids we need to eat. Animal sources of protein like eggs and meat are complete sources, that is, one portion of such a food contains all eight essential amino acids. The other 12 we can synthesize from the essential 8.
Humans are omnivores and not vegetarians. Animals that exclusively eat plants are able to synthesize amino acids from a smaller essential list eating monotonous plant sources. Humans who choose to artificially emulate true herbivores by eating only plant sources must consciously mix and match different plant sources, and unless they want to eat their own feces (I am not making that up -it would take about 30% by weight), must artificially supplement to get vitamin B12 that we can otherwise only get from the animal sources we evolved to eat. Animal sources of protein like eggs and meat are complete sources of amino acids – no mix and match required to get the essentials.
Fats and oils are described by class here, but generally are in the form of triacylglycerols or triglycerides (TAGs), three fatty acids chains on a glycerol backbone. Lipid is the technical term, but lets use fats for short. The fat composition of our diets affects cell wall and other vital functions, and the ratios of fats like Omega 6 and Omega 3 has important effects on immune function and inflammation.
As a fuel, fats are nonpariel. The FDA and the AHA and the ADA and all the lipophobes say to avoid fats because they are 9 kcal/ g (versus roughly 4kcal/g for proteins and carbs) and this caloric density will somehow by itself make you gain weight. I never saw a wild animal titrate their food by weight and humans don't either. We stop eating when we are no longer hungry and nothing turns off hunger like fats. The caloric density of fat is not an accident. Animals evolved to store energy efficiently as fat, and humans evolved to eat the the fat that prey animals we co-evolved with have stored “on our behalf”. We store the majority of the extra energy in our own bodies, whether derived from fats or sugars or proteins, as fat, especially saturated fat. To suspect that the saturated fat we store in our own bodies in such large amounts causes disease is wholly implausible, and I have yet to see any convincing scientific evidence that it does. Animal fats are quite simply the anchor food source of the PaNu approach.
Carbohydrates are simple sugars (glucose, fructose, etc..) or polymers (long chains) of simple sugars called starches. Glucose and Fructose are simple sugars. One glucose joined to one fructose is one sucrose disaccharide molecule. Sucrose and high fructose corn syrup or HFCS (manufactured from corn) are metabolically equivalent for all practical purposes. They are equally bad for you. Sugars can be burned as fuel or converted into storage fat in our bodies. They have other biological functions within the body, but importantly, there is no such thing as an essential carbohydrate. Any sugar or starch needed internally can be synthesized from scratch. Unlike the case with Proteins and Fats, starches and sugars are basically just fuel. PaNu theory (well, basic cell biology, actually) recognizes that sugars are the oldest cell fuel. Many bacteria and primitive organisms, and dedifferentiated cancer cells, can only use glucose (sugar) as fuel. During the long evolution of animals, the ability to store and use fatty acids evolved as well. This has had huge advantages in energy storage and efficiency for animals. It is my working hypothesis that during much of human evolution, fatty acids were a much more utilized fuel source within the human body, and even though it was adaptive during our evolution for humans to exploit carbohydrate rich food sources when in a food scarce environment, our current food abundant environment has us using glucose as an internal fuel far more than what we are biologically adapted to. This is the first central dogma, if you will, of PaNu theory. Lets state this central dogma for reinforcement:
I. The first core departure from the evolutionary metabolic milieu (EM2) is the degree to which we use glucose as an internal fuel relative to fatty acids.
In a food abundant environment, where there is no caloric deficit, carbohydrates as a large fraction of caloric intake create a situation where our metabolism is not spending enough time in or near the fat-burning state known as ketosis. The consequence of this is the metabolic syndrome, which is insulin resistance, diabetes, hypertension, obesity and a variety of other diseases that have highly suggestive lines of evidence connecting them to chronically increased levels of insulin and/or serum glucose – including coronary artery disease, deep venous thrombosis, pulmonary embolism, atrial fibrillation, atherosclerosis, alzheimer dementia, degenerative diseases and even the most common cancers like breast, colon, lung and prostate.
Now, as a physician who sees a wide variety of ailments in the context of people who are ill enough to need MRIs, CT scans and Ultrasounds, I can tell you that this short list is about 60% or more of the serious diseases that I encounter routinely. Imagine if these diseases of civilization were not an inevitable consequence of aging, each with a different cause, but were all a consequence of living long enough despite eating the wrong diet – a diet that deviates from the EM2. That is what I believe to be the case.
My first central dogma is just a subtle extension of Gary Taubes' carbohydrate hypothesis. For the comprehensive tour-de-force argument for the carbohydrate hypothesis, read Good Calories, Bad Calories by Gary Taubes
So what can we do to get closer to the fat-burning metabolism of the EM2?
Let's look at our current diet (not yours or mine, the average north american's) and see what it's macronutrient composition is. (These figures are approximate but pretty close)
Average daily calories 2300
Sugar and HFCS 100 lbs/yr 496 kcal/day per capita = 22% Source – HFCS web site
Flour 138 lbs/yr 685 kcal/day per capita = 30% Source - The Wheat Foods Council
The percentage figures as a fraction of daily calories are 22% Sugar and HFCS and 30% from wheat flour.
These figures may be high and count wastage and protein (gluten), so lets round the flour carbs down to 20%. Most figures for current total carb consumption are 55%. So, being generous, we can ballpark all other sources of carbs like vegetables and corn and rice and fruit, etc. at 15% of calories.
So we have, roughly, 22% sugar and HFCS, 20% flour carbs, 15% veggie carbs, 16% protein and 27% fat.
Note that all the vitamins, and all of the essential aas and fatty acids (if we are getting them) are coming from 58% of our diet.
To get closer to the fat burning metabolism of the EM2, what can we do with this as a starting point?
Insulin levels can be low despite a high carbohydrate fraction and we are in ketosis if we are in constant caloric deficit, but this has nasty side effects like lethargy, muscle wastage and well, eventual death if we keep it up. Being hungry all the time is no fun either.
How about eating 55% carbs and only eating every other day, a rigorous form of intermittent fasting? Well, there is some evidence that would work, but I would not prefer alternate day eating to once or twice a day, and try fasting 24 hours after big plates of pasta sometime. Good luck with that.
Perhaps we could agree that Sucrose, HFCS and white flour are providing absolutely nothing essential to our diets, and the sugars (they are all nothing but sugars with some gluten protein in the flour) are just stimulating insulin secretion (glucose) and if not stimulating insulin, they are being converted directly to fat, damaging our liver, and making us eat more by not shutting off our appetites (fructose). To make our cells more reliant on fatty acids and avoid the damage from too much sugar in the diet and the bloodstream, we will completely eliminate 42% of our diet. That is step 1 of PaNu.
Now we have a 42% hole in our diet. We can fill it with more macronutrients from the following:
a) 15% other carbs category choosing from starchy foods like corn, rice, potatoes or fructose laden fruit.
b) 15% other carbs but choosing non-starchy vegetables like green salads, broccoli, asparagus etc.
c) Protein 16%
d) Fats 27% (This number has actually decreased at the same time obesity has increased over the past 20 years)
The a) choices just add back glucose and fructose we just removed even if we picked up a few vitamins from sugary fruit. The b) choices might be OK, but if you avoid starch and add green vegetables till they are over 60% of calories you have added most of the carbs right back and you are now chewing for hours a day like a chimpanzee just to get nourishment. *
Now, people don't eat pure macronutrients once they've eliminated sugars and flour. They eat foods that are composed of macronutrients. We need lower the carbohydrate fraction by adding back foods that don't just raise it back again. Since Fats have zero insulin response, are a great fuel source, and give great satiety, why not do this:
Increase Fats to 65-70%, and cut out all residual grains, legumes, and starchy vegetables like potatoes, corn and rice so that only the green salads and non starchy veggies are left. This will get carbs down to 10% (roughly 50g per day) and absolutely minimize glucose, fructose and insulin effects. For the reasons elucidated here we will not allow mechanically extracted seed oils into the diet. This leaves animal sources like butter, cream and flesh of animals like beef, chicken, pork and fish. Now, when we seek out these natural unprocessed animal sources of fat, we will get a bit more animal protein and many more vitamins in the bargain.
Keep carbs around 10%, seek out animal fats, let protein come along for the ride and you will get close to these ratios, + or – 5% for each:
65-70% Fat, 20-25% Protein, and 10% carbohydrates.
This may well be more protein than you need.
No harm reducing it to 15% and adding more cream or butter
Try it. Record everything you eat for a few days while sticking to 1 through 4.
Use Fitday to calculate your ratios. It will be hard to radically deviate from the above ratios unless you purposefully try to subvert it.
Now is when you ( well not you, but those who buy the healthy grains propaganda) say:
Where are the healthy grains?
Answer in the next post.
*Greens are fibrous and not starchy or calorie dense, so if we add enough back to replace the lost calories, we are eating a huge amount of vegetables now. This is in fact advocated by authors like Colin Campbell and Joel Furhman - it can have some effect as the mechanical satiety and sheer work of eating may reduce your caloric intake. However, you will be having a minimal effect on insulin levels at the expense of eating fewer higher quality animal foods and absurd amounts of fiber - this approach only makes sense if you think animal products and fats per se are unhealthy - they are not. Also you just don't need that many vegetables in general and you don't need "fiber" at all.
No comments:
Post a Comment