Red meat was making me physically sick within an hour of consumption. Didn't matter what it was or how lean. Beef, bison, venison, whatever. It took me several years to figure this out. One day I got sick after eating a burger. So I decided to go a week with no red meat consumption. I started feeling better. So I went a month and didn't have any issues. I'm now almost 2 years without eating red meat and I am in the best shape of my life. Pork is also considered a red meat. I've reduced my intake of that as well. I can't give that up completely because bacon is the best food on the planet.
With regards to diets, I went on a bit journey with my weight at the same time I gave up red meat. I weighed 217 pounds. I wasn't fat but I also wasn't carrying the weight properly. I didn't do any fads. I basically managed portions, stopped eating late at night, and exercised more. I dropped to 191 in about 10 months. It might have happened sooner but I allowed myself to indulge when I felt like I needed to. especially on weekends.
After that 10 months and losing the weight, I looked in the mirror and realized that even though I was lighter, I didn't necessarily look better. I looked thinner, not fitter. I was listening to a fitness podcast when i took some of their tips to being more fit. I (try very hard) not to eat carbs after 5PM. So I changed things up and put on pounds to get back up to the 205-209 range. I lift more weights than I have in the past, and I do different forms of aerobic and cardio every day. I'm leaner, stronger, and look fitter than I have ever been.
The one thing that stuck with me in the podcast was they said your weight is whatever you tell someone it is. It doesn't really matter if you're fit. You could look at me and I could tell you I weigh 220 and you'd believe me. I could tell you 195 and you'd believe me. It's because of how i carry the weight.
All in all, I plan to eventually go back up to the 220 area. I'm doing a lot of muscle building training right now so I am consuming more calories in order to feed that. But now that i am mostly (weekend beers notwithstanding) watching when I eat as opposed to what, within reason, I think I will be able to carry the weight properly and look better doing it.