The ideal diet for heart and overall health restricts carbohydrate intake. I say this because carbohydrates:
Make you fat--Carbohydrates increase visceral fat, in particular.
Increase triglycerides
Reduce HDL
Increase small LDL particles
Increase glycation of LDL
Increase blood pressure
Increase c-reactive protein
Reducing carbohydrates reverses all the above.
But here's a common mistake many people make when following a low-carbohydrate diet: Converting to a low-carb, high-animal product diet.
It accounts for a breakfast of a 3-egg omelette with cheese and butter, 4 strips of bacon, 2 sausages, cream in coffee. Low-carb? It certainly is. But it is a purely high-animal product, no-plant-based meal.
I believe a strong argument can be made that a low-carbohydrate but plant-based diet with animal products as the side dish is a better way to go.
Consider that:
1) Animal products have little to no fiber, while plant-based products like spinach, avocado, and walnuts and other raw nuts have substantial quantities.
2) Plant products are a source of polyphenols and flavonoids--This encompasses a large universe of nutrients, from epigallocatechins in tea, polymeric procyanidins from cocoa, to hydroxytyrosol from olives, and anthocyanins from red wine and eggplant. The inflow of these beneficial compounds needs to be frequent and generous, not piddly amounts taken infrequently.
3) Vitamin C--While it's easy to obtain, the fact that you and I need to obtain vitamin C from frequent ingestion of plant sources suggests that humans were meant to eat lots of plants. While it may require a few months of deficiency before your teeth fall out, imagine what low-grade deficiency can do over a long period.
4) Vitamin K1--Rich in green vegetables, vitamin K1 is virtually absent in animal products.
5) Tocotrienols--I've been watching the data on this fascinating family of powerful oil-soluble antioxidants unfold for 20 years. Tocotrienols come only from plants. (I recently had an extended conversation with the brilliant biochemist, Dr. Barrie Tan, who is incredibly knowledgeable about tocotrienols, having developed several methods of extraction from plants, including his discovery of the highly concentrated source, annatto. Be sure to watch for future conversations about tocotrienols.)
6) Meats and dairy yield a net acid load--While plant foods are net basic. At the very least, this yields risk for osteoporosis, since acids are ultimately buffered by basic calcium salts from the bones. Tissue and blood pH is a tightly regulated system; veering off just a teensy-weensy bit from the normal pH of 7.4 to an acidic pH of, say, 7.2, leads to . . . death. In short, pH control is very important. A net acid challenge from animal products is a lot like drinking carbonated soda, a huge acid challenge that leads to osteoporosis and other health issues.
Conversely, a pure plant-based diet has its own set of problems. Eating a pure plant-based diet can lead to deficiencies of vitamin B12, omega-3 fatty acids (no, linolenic acid from flaxseed will NOT cut it), vitamin K2, carnitine, and coenzyme Q10.
So, rather than a breakfast of 3-egg omelet with bacon, sausage, cream, and cheese, how about a handful of pecans, some blueberries, and a 2-egg omelet made with basil-olive oil pesto? Or a spinach salad with walnuts, feta cheese, and lots of olive oil?