Grass fed beef can be a powerful addition to a low carb or ketogenic diet. Animals raised naturally on grassland make highly nutritious meat that is richer in omega 3 fats than grain-fed meat. Grass fed beef is also higher in vitamins A and E.
This chart from the wonderful website eatwild.com shows what happens to the omega 3 fat in cows sent to feedlots to "fatten up". Our ancestral diet had an omega 6 to omega 3 ratio of about 1:1, ours is now closer to 20:1.
While some omega 6 fats are necessary in the human diet, they are inflammatory in excess, and a 20:1 ratio is highly inflammatory! Inflammation triggers a cascade of physiological events that underlie all the chronic diseases, including type 2 diabetes, heart disease, and Alzheimer's.
We also tend to think of "meat" as muscle meat (think steaks), but the most nutritious cuts of an animal are the liver, kidneys, heart, joint cartilage, and marrow. These parts of the animal were the most cherished in times past, precisely because they were so nutritious.
Primitive man did not have a USDA Nutrient Content of Foods chart, he was innately drawn to the most nutritious parts of the animal, eating what we would now call "nose-to-tail".
In generations past, all animals were grass fed or raised on pasture. Our great grandparents did not send their animals to feedlots to fatten them up on grain and to be fed antibiotics (due to overcrowding and unsanitary conditions) and hormones (so they retain water, weigh more and bring more profit at slaughter). They ate all cuts of grass fed meat without fear of fat, and did not suffer the epidemic of chronic diseases that are now rampant.
Our beliefs about what constituted a healthy diet changed in the 1960s and 70s as early researchers came to the erroneous conclusion that saturated fat caused heart disease, which set us all on a course of increased carb consumption. We also began eating highly refined seed oils that are high in omega 6 fats, and stopped eating the more healthful omega 3 fats that are found in grass fed beef.
Emerging research has shown heart disease to be a cascade of events initiated by inflammation, which is caused by a high-carb diet with lots of "healthy" polyunsaturated omega 6 fat.
Changing this established, unhealthy dietary paradigm is going to be like steering a battleship, however - it's going to take some time to turn it around. You don't have to wait for the mainstream to catch up to its own research though, you can follow the science yourself, now.
It took me awhile to get over my own deeply ingrained fear of fat. I can honestly say after years now of gobbling up the fat on steaks, the bone marrow in soups, the veggies sauteed in duck fat or home-rendered tallow, I feel much better, and my laboratory test blood markers for heart disease risk are better.
Cattle have been raised by humans since agriculture began about 10,000 years ago. The original wild "cow" was the auroch, which is now extinct but whose descendants have lived alongside humans throughout the history of agriculture.
Cattle that have been raised their entire lives on pasture not only live a
natural, free-ranging life, they play an important role in both grassland ecosystems and in human health. In purchasing grass fed meats instead of grain-fed, you are actually helping restore grasslands.
Overgrazing can cause desertification of grasslands if we don't understand how ruminant animals should move across a landscape, churning last-year's dead grass stalks down into the ground where the plant's carbon can decay back into the soil, rather than forming an impenetrable mat on the surface or volatilizing off into the atmosphere.
Animals also fertilize the soil with their manure, where the resulting microbial action replenishes and revitalizes the soil.
In the past we allowed animals to deplete a landscape by confining them to an area too small to support the working of the ecosystem as a whole.
The following video provides an excellent summary of why supporting ranchers who raise grass fed meat can be instrumental in restoring landscapes, not depleting them. Cattle and humans are both part of a larger ecosystem that benefits and sustains both.