I can only lose weight keeping a certain diet (other diets, even suggested by doctors failed, also exercises don't work, doing or not exercises don't change the speed of me losing weight).
That diet is mostly avoiding carbohydrates, my lunch was mostly green stuff (eg: cabbage and similar things) and some protein (like egg, cheese, etc...) and for dinner a can of tuna.
When I do that, I can lose 1kg per week.
When I don't do that, I get back 1kg per week...
In two years I went from 126kg to 99kg to 110kg to 98kg to 119kg, if I eat tuna every dinner, I lose 1kg per week more or less, if I don't (for example if I eat tuna inside a bread, or eat a pork sandwich) then I get fat again.
How I stay below 100kg without eating tuna every single day forever?
EDIT: From those wondering why tuna? Well, I like tuna since I was a little kid, this is why when I designed my weight loss diet I used tuna as protein source...
EDIT2: I already eat less than the average person, weird questions relating my diet ("why you eat so little? Are you sick?" or "why you don't eat rice like that builder dude over there? You are young, rice is good!" ) are not uncommon.