pretty radical 
Very sustainable. I've been on a diet of mostly fatty red meat, some eggs, some cheese, bacon, heavy cream and butter for 5+ years, for health reasons. I keep my carbs below 20g per day and avoid plant-based foods for the most part. Best and most sustainable diet for me ever. I plan to stay on it for the rest of my life.
The past six months I've been eating a grilled 6-8oz NY strip seasoned with salt 1s thing in the morning, nothing else. I eat the same thing for lunch. For my early afternoon dinner I eat 2 whole eggs with 3-4oz shredded cheddar cheese, a cup of decaf coffee with heavy cream and artificial sweetener. Delicious.
On the weekends I'll eat one very large meal of nothing but meat at a local Brazilian steak house, and on Sunday I usually eat one meal: 1 lbs ground beef mixed with 2oz chopped beef liver, low-carb chunky salsa, and shredded cheddar cheese. Delicious.
My physical and mental health are now much better than ever, and improving every year I stay on this way of eating.
When you have a shit thats all the crap you ate yesterday that the body didnt use.
It's actually the opposite. If you eat a very low-carb, animal-based food diet, your bowel movements become much smaller and a lot less frequent because your body absorbs and utilizes most of those foods. Still, your bowel movements will be very normal and easy to pass, neither hard nor too soft.
No need to debate or argue about this. Anyone here can try this for 3 months and see for themselves.