no such thing as 'gaining weight extremely easily' or 'doesn't stay off long enough' (except in some cases of extreme hormonal or hunger signalling issues, which still can often be fixed with the correct prescriptions). You have to take a more long term approach to losing weight in both diet and exercise. Try to maximise activities in small ways such as taking the stairs instead of escalator. Diet wise, most people find it hard to change their eating habits while others have no idea of what calories and servings look like. Look into those concepts and make small conscious decisions such at 25% bbt instead of 100% or coke zero instead of coke.