What actually happens is that you get satiated a LOT faster because beef is so nutrient dense, so you end up eating fewer calories and most people only eat two meals a day because they just stay satiated for so long. You also never experience the drowsiness that normally comes after eating.
This is a zero carb diet which is high in protein, so you'll find yourself effortlessly putting on muscle and losing belly fat.
When I say "entirely beef", that means "you can't put anything in your mouth that is not literally part of a cow" -- so that means no junk food, no sugar, no alcohol, not calories through drinking anything. It is the ultimate elimination diet because it is nutritionally complete yet ridiculously simple.
People call it "the lion diet" and if you actually try it you'll end up in phenomenal shape and you'll feel like you're running on jet fuel.