| | Ed,
You make my argument for me, for as you say: The fat quality and quantity in the wild animals our Stone Age ancestors ate was vastly different from the types and quantity of fat found in the fatty meats typically consumed in the US. A 100-gram serving of roast buffalo contains only 2.4 grams of fat, and 0.9 g of saturated fat, whereas a 100-gram, T-bone beefsteak contains a whopping 23 grams of fat, and 9 grams of artery clogging saturated fat. So, let us see what percentage of total calories are fat in this example of stone-age meat. There are 9 calories per gram of fat and 4 calories per gram of protein and carbohydrate. So that means that the calories from fat in this 100 gram portion of buffalo meat are 2.4 x 9 or 21.6, and the remaining calories (from protein) are 97.6 x 4 or 390.4. Thus, we see that the total calories in this 100 gram portion are 412, of which only 21.6 are fat. That means that the percent of total calories as fat is 21.6/412 or 5.24%. Keep that figure firmly in mind. Additionally, the bison roast contains 215 mg of heart-healthy, omega-3 fatty acids whereas the T-bone steak contains a paltry 46 mg. Precisely! But then you say, The types of meats permitted on The Paleo Diet are lean meats (beef, pork, poultry, fish, seafood) trimmed of visible fat. These meats are healthful because they have nutritional characteristics similar to wild animals. Do they? I don't think so. I was at the supermarket today, and the leanest beef I could find was 96% fat free, 4 ounces of which contained 150 calories, of which 40 were fat. That means that 27% of the calories were from fat, compared to just over 5% for the bison. So, the leanest beef available at the supermarket had over 5 times the percent of fat calories as the meat our Stone Age ancestors consumed, which is precisely my point. Even the leanest meat available today doesn't come close to matching the meat available during the Paleolithic era. Recent clinical studies have shown that lean protein-based diets are more effective in improving blood cholesterol and other blood lipid levels than are low-fat, high-carbohydrate diets. Doesn't that depend on how low the low-fat diets were and on what kind of carbohydrates were included in the high-carbohydrate diets? On the low-fat, high-carbohydrate Pritikin diet, I lowered my cholesterol from 250 to 120 mg/dL. Pritikin lowered his from 350 to 120. And many other people have had similarly dramatic reductions in their cholesterol. I can virtually guarantee that you won't get those kind of results from the diet you advocate. High protein diets have also been shown to lower blood homocysteine levels, another risk factor for heart disease. Oh, really? Then how do you explain the following conclusions from a study in the American Journal of Clinical Nutrition (Vol. 82, No. 3, 553-558, September 2005)? "In conclusion, compared with a high-carbohydrate diet, a high-protein diet raises tHcy [homocysteine] concentrations throughout the day, both acutely and after 1 wk of habituation. Fasting tHcy concentrations are not affected by a high-protein diet. As we previously showed, the extent of the postprandial rise in tHcy is likely to be modified by the amino acid composition of the protein diet. The clinical relevance of our finding depends on whether high concentrations of tHcy—in particular, high postprandial concentrations—do indeed cause CVD. If so, it might be important to avoid excessive protein intake." [Emphasis added]
I agree with you that polyunsaturated vegetable oils contribute to the oxidation of LDL cholesterol, which is one reason they're excluded from the Pritikin diet. Refined sugars are also excluded, as well as such things as honey, brown sugar, syrup, molasses and high-fructose corn syrup. But whole grains have been show to contain antioxidants, and legumes are relatively low-glycemic foods, so it is difficult to see how these could be significant causes of LDL oxidation. There will always be some oxidation of LDL cholesterol, no matter what you do, so the more LDL you have, the greater the risk of oxidation, all other things being equal. The best defense is to keep LDL to a minimum.
(Edited by William Dwyer on 8/31, 6:05pm)
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Any exercise carried on beyond the least amount required to stimulate an optimal increase is not merely a waste of effort, it is actually highly counterproductive.
