Overweight/obesity are associated with a host of medical conditions which can be improved or cured:
Depression/Low self esteem
Certain cancers and many more
Overweight/obesity can be caused by hormonal or genetic conditions which often require expert physician evaluation for their detection and treatment. Additionally, obesity can cause many diseases as listed above.
Weight loss often reverses these illnesses. Medications used to treat can be reduced and in many cases eliminated entirely. This should only be done by a physician.
Beloved, I wish above all things I pray that thou mayest prosper and be in health, even as thy soul prospereth. 3John 1:2