For me personally, low carb diets work, and the nice thing is I never feel hungry. I cut out all sugar, most all starch, and that’s it. I eat as much beef, chicken, pork, eggs, and fish as I want and limit my veggies to those that are non-starchy (no rice, corn, potatoes, or lentils). I also don’t think of it as “a diet”, it’s just what I eat every day.
I hired a trainer at the gym last October and he is GREAT. He basically eats meat and not much else. That high protein / low carb diet really works for him — lean and strong.
I’d worry that is not a healthy diet, though. A good friend who was fit as a fiddle (lots of ice hockey, long hard bike rides, hiking in the mountains) suddenly couldn’t do a hike last summer. He had several stents put in the next day. His doctor said “plant based diet for you from now on” and he gave up all meat and his beloved crab and salmon. He loves going fishing and crabbing around Victoria, BC, Canada. I’m impressed he made the change, but that is brutal.