Well, I can tell you for a fact, in the five years we've been married, my husband has gained eighty pounds, while I've been eating healthy, exercising, and LOST 23 pounds! It drives me nuts, the oversize shirts he wears to hide the huge belly, and when we go to a restaurant, he gives no thought to his weight when he orders fries, pasta, etc.
Every spring, he promises to start hiking with me and never goes.
A few weeks ago, his secretary from work called him up to say she had seen me. (hadn't seen her since I lost my weight.) She is gay. She said, "Wow, I saw your wife yesterday. She is HOT! You better lose some weight, buddy, or you're gonna lose her!" That shook him up. For about a week, now he's back to cherry pie. Arrrrgh!!!
In our case the man let himself go after getting married. He says it's because he's just so happy and comfortable, he feels he can let his hair down. His weight really upsets me, because I'm afraid he'll develop diabetes, high blood pressure, or have a heart attack. Other than that, he's a good man, with a heart of gold.