I'm a big guy. I would compare myself to Jack Black, maybe a little taller and bigger. I've always thought that women preferred guys who weren't overweight until I met a guy at work who is much bigger than I am and is married. I'd like to know what his secret is.

Every person has a personal preference. Some women like bigger men, some men like bigger women. As far as the secret, what about personality?

Of course some women like bigger men. Although, if they really truly are the one for you, they will look past your exterior and see you for your personality. There is no secret. Just be yourself and one day you will find the one.

Let me see I am over 50, almost bald, walk with a cane, I weigh about 260. After my wife left, I have plenty of chances on dates.

It is a matter of asking enough people and finding someone who either does not care about looks ( most personality is a lot more important in adults that are really grown up) and really just asking enough people.

My husband is overweight, but I love him.
I never did have a preference about looks... well
They had to be clean, smell good, well groomed. You know they had to have good grooming habits.

really doesn't matter. Will a guy that has a six pack abs have a better shot with a girl at a random club than you? Generally... he might, but it's all about how you carry yourself. If you carry yourself with the attitude that you are possibly the best thing to happen since sliced bread (and this is not being a cocky jerk, I'm talking about confidence), then you probably have a better shot.

Everone has their own preferences! Some like bigger men and some like small men.

Think of every couple you have seen lately, they are not the same yeah! That should answer your question, different people like different things!

As to what his secret is... Most likely just being himself! Don't compare yourself to others just embrace yourself and enjoy being who you are!
:)