The reason so many people are just sure that 1200-1400 calories are best for them is that they have been on diets in the past and that is what they had to do. BUT apparently the diet did not work and that is why they are here.
Depriving your body of fuel will get you no where in the big picture. Healthy eating and establishing good habits will help you lose weight AND keep it off. NO MORE DIETS, they don't work, that is why so many of us have been on countless diets and we will no longer go down that dead end road.
If your doctor told you to take a certain dose of medication, but in your past you took less, and all your friends too less what would you do? I would think you would leave it up to the professionals.....
Annette