There is a huge difference,,,,,,,,,given that gluttony is a sin, but not ALL obesity is caused by gluttony. And, even if that is the case, there MUST be an underlying intention to end ones life. Folks pigging out sinfully are not necessarily attempting to kill themselves.
Your comparison is lacking in credibility, no offense, it just is. By your ideology, a person who speeds while driving a car is trying to kill themselves, for speeding is surely one way to die, and many do.....
Suicide (if successful) is usually considered, contemplated, maybe even discussed (as in suicide pacts), planned and carried out. That is far different from pigging out on Double Whoppers with Cheese and x-tra Fries