its whats in your genetic make up, not what you put in your mouth , me and my wife eat the same food 24/7 . i (never ) put weight on i stay roughly the same weight 40 years. my wife alot heavier than me even though we eat the same food, plus she worked 35 years paying taxes/ nhs , if she need treatment for loosing weight she should get it , after paying her way, but she dont bother. she just lives her life the best she can .
Your body converts food into energy for you to use, if you do not use all this energy the body then saves it as fat for use when you do need it, so