My husband is one of those people who never gains a pound, no matter what or how much he eats.

He has been eating low-carb along with me on Atkins, and I'm worried about this. He says he's fine, and we are eating well, but I worry that it might be affecting him. He very rarely gets sick, but last week, he caught a brutal chest cold.

Should I try to encourage him to include some potatoes or noodles or breads in his meals? He says he's fine. (I suspect he doesn't want to tempt me, although I feel no such temptation.)

Are there people who should not low-carb?