Hello all. This is my first post to the list.

I have a question, but first a little background.

I started gaining weight in my mid 40's. I tried the low-fat diets
advocated by Covert Bailey and Dean Ornish. I was cold and hungry all the
time, and immediately regained weight when I resumed my standard American
diet. Next I tried the Zone diet. It was better, but still not that
satisfactory. I turned to the Atkins diet, and after I’d added a lot of
green salads and steamed greens, I found that it was the most satisfying.
But the unlimited quantities of rich meats and dairy did not result in the
promised weight loss. I did a lot of web research, and finally came up
with a method that works fairly well: 1) exercise every day; 2) eat lots
of leafy greens B 3) eat about a pound of meat each day; and 4) avoid
sugar, starch, and alcohol. I have lost about 50 pounds over the past
three years, with plateaus due to sports injuries, holidays, and
occasional lapses into comfort foods. I want to lose another 25 pounds
within the next six months, so I began reading The Paleo Diet, by Loren
Cordain, looking for some new ideas.

I learned a lot about insulin resistance, osteoporosis, autoimmune
diseases, salt, lectins, the balance between sodium and potassium, and the
balance between acid foods and alkaline foods. He makes sense when he
advocates eating like our ancestors. He mentions organ meats in passing,
but puts a strong emphasis on eating lean muscle meats. I would think that
if we want to eat like our ancestors, we would focus on bone marrow and
organ meats, which are not lean.

When the climate changed millions of years ago, and the rai
n forest was
replaced by savanna filled with grazing herds and lions, our ancestors
became scavengers, eating lots of bone marrow and brain. They became
hunters a million years after that, and still ate the organs first.

I understand that modern Americans are very squeamish about organ meats.
Fortunately, I’ve spent the last two years in China, where these cultural
prejudices are not shared. They have delicious recipes for bone marrow
soup with fresh ginger,  braised pork brain with green onion, garlic and
onion braised tongue, and stir-fried pork heart with chili peppers. These
organ meats are delicious, full of good nutrition, and were certainly
eaten by our pre-TV American ancestors.

I went to the USDA Nutrient Database and to try and reconcile the benefits
of organ meats with the danger of feedlot muscle meat. It shows that 100
grams of caribou bone marrow has 6.7g protein, 84.4g fat, and no c
arb.
Pork brain (100 g) has 10.3g of protein, 9.2g of fat, and 2195mg
cholesterol. Beef tongue (100g)  has 14.9g protein and 16.1g fat. Beef
ribeye (small end, 0% fat, 100g) has 17.5g protein, and 22.1g fat. Fresh
whole egg (100g) has 12.6g protein, 9.9g fat, and 423mg cholesterol.

So here is my question:

Can anyone explain why organ meats are good for us, but fatty muscle meats
and eggs are bad for us? They seem to have pretty similar percentages of
saturated, monounsaturated, and polyunsaturated fats. Both have saturated
fats that are mostly 16:0 and 18:0. Pork brain has DPA and DHA, but beef
brain doesn’t; and they both have five time the cholesterol of eggs.

Thanks for any insights into this issue,
Robert