Obesity is a natural reaction to an unnatural food environment. You get fat because you eat processed food that has way too much energy (calories like fat and sugar) and too little nutrition and bulk. If you just eat less junk, as you already said, your stomach is half empty and you will feel hungry all the time. Nobody can live like that for long. So the only option to lose weight forever is changing your diet to Whole food plant based. This is not me being smart, but science.