I'm working on an mobile app that would help people with ED. Could you help in making it the most effective as it is possible?

What do you think of the claim that psychological attitude can influence feeling of hunger?

For example why changing regular chocolate to sugar free chocolate does not help to loose weight? Why after consuming fitness cornflakes do I still feel hungry?

Do you believe that if we are convinced that a product is caloric dense then after consuming it we feel more full. And that the opposite is true, if we are convinced the same product is low in calories we will feel hungry?

Some companies advertise their products as low-fat, light or defatted. However, if I carefully compare etiquettes then they reveal that there is little difference from original product in terms of its influence on our health. However the consumption and sales of such products increases, as people think they have smaller calorific value and eat them more.

Unfortunately I think that those who care of their health or want to loose weight can feel surprised that their efforts are ineffective.

What's your opinion?