Get better deodorant. Being overweight doesn't make you smell more, it just makes you sweat more. So you may find you need to shower more often that others if the sweat builds up, but it's not like your actual sweat itself starts off smelling different to non overweight individuals. I find solid sticks work the best. Mitchum works wonders for me. Anything else just has a smell to mask the smell from sweat but is never enough for me.
As for crotch and feet, you can buy absorbing powders to soak up the sweat. It also helps to trim hair in pits and crotch. I keep both very short. If it's bad in pits and you never wear anything that shows them, or you just don't care, shave them entirely. Hair = more sweat being trapped and lingering. Honestly, I admit that as of last week, I shave them entirely because it just leads to far easier cleaning. After taking a shower and scrubbing away there with shower gel, I left the shower shocked that they STILL smelled, so I just shaved and problem was immediately gone.
I'm not overweight but I workout and train A LOT! And I've noticed I sweat a ton more than I used to. After a hard Taekwon-do class, when I'm laying on the floor for cool down stretches, it's like a puddle starts forming around me. However, by using stick, odorless deodorant and powder, it's meant that the smell isn't so bad at all, if there's any smell at all!
