« I am not strong enough » & « I don’t have willpower » aren’t one of those 
The root causes I see the most in my clinic include:- Trying to numb stress and anxiety through food- Restricting food or food groups which leads to cravings- Not being mindful & mentally present during meals- Not sleeping well- Not drinking enough water- Skipping meals- Eating quickly So, please, before trying to follow a restrictive diet to avoid overeating & gaining weight, take a look at your eating habits, overall lifestyle, feelings and emotions 
I will be more than happy to help if you need me to 
