Food just affects everyone differently. There is always one thing that will work well for YOU, but not for everyone else. For me and weight loss, if I truly want to lose weight, then I need to eat about 1800 calories a day (I weight around 310 now I think). But, I can maintain from anywhere from 2000 to 4000 calories a day. If I eat over 4500, then I gain weight.
The problem isn’t just that though, it is how your body is affected by the variance, at least in my experience. For me, I can eat McDonalds for 3 days straight and not gain anything, maybe a pound. But, if I were to eat, say, 10 cookies a day for 3 days, I’d gain like 8 pounds. I have no idea why, but has to do something with insulin, water levels in the body, etc.
The hardest thing to figure out is what you an and can’t do / eat. Start off with all the calculators out there, start tracking your food with MyFitnessPal for a week, then you will have a good idea.
Also, the rule is cut 500 calories a day to lose a pound a week. Well, this is bull shit, it never works, at least not when you are over 300 lbs. You lose 7 pounds in 3 days, then gain 8 in 3 days, then lose 1 in one day, it’s so frustrating lol.
But, like T3hPwnisher said, the more you push, the more you burn, which basically means the more you can eat. I am getting stronger recently, and I now walk around with my shirt off. I’m not saying I should lol, but at least I don’t feel like a total lard, I just feel like a fat dude that is huge, instead of just a fat dude.
One thing that helps though is if you want to eat more, then cut out carbs and replace with protein.