I was about 6'1" 340lbs about a year ago. Went to the doctor for something unrelated and found out I was type 2 diabetic (big surprise) and was going to have to be put on medication / insulin shots etc.. f*ck that.
Been on the Ketogenic diet since then. Low Carb High Fat diet. No starches/sugar/very little carbs from vegetables etc. Basically forces your body to burn fat for energy instead of glucose (sugar/carbs etc). There's more to it but that's the cliff notes version.
Its tough sometimes. and going out to eat can sometimes be a huge pain in the ***. But its all about learning what you can and can't eat. It's amazing when you start reading labels and see how much sugar and BS is put in foods we buy everyday..
Slowly but surely down to ~280 and still going. With literally zero exercise (desk IT job). Check out the
everything about keto forum. Get lots of info and support there..
Also can recommend the Myfitnesspal app thing if you want help tracking ****. I hate doing it but can help you realize how many calories and carbs you taking in.
Its not for everyone but its definitely working for me. Might be worth looking into.