one thing that makes it hard for some people to lose weight, even if they dont eat too much and work out is that they eat after working out. this pretty much makes the work out useless and only makes you grow muscles, not lose fat. if i remember right, you shouldnt eat 4 hours after working out if you want to get most out of losing weight with exercising. there are two hormones in your body which one of regulates storing of energy and one makes you use the energy you got stored. when you eat, the one that makes you use the energy you are eating is triggered, but when you exercise, the one that uses stored energy is triggered(and continues being the dominant one for hours after exercise, thats why you keep losing weight, even after you stop moving, the actual moving doesent make you even lose that much weight).
also one thing that people dont realize is that starch is just 3 sugars binded together, so basically eating white bread is equal to eating candy, with the difference that starch brakes down to 3 sugar molecules faster than eating white sugar does, raising your blood sugar levels even faster than eating white sugar.
fat people often are fat because they are careless about eating and moving and how to do it correctly. or they are just plain dumb and crying cuz they are fat and going to mcdonalds to soothe their pain and not even realizing that eating junk food makes them unhappy, not only because it makes them fat and being fat makes them sad, but because they arent giving their brains the building blocks to make dopamine etc and thus feeling depressed.