A new study claims that a partner’s sudden interest in weight loss could really mean they’re losing interest in you. German Professor Thomas Klein, who studies the link between happiness and body weight, found that people in steady relationships who abruptly begin to diet and exercise are possibly planning to break it up.
Relationship expert Leslie Seppinni of Los Angeles agrees, also noting that weight loss might be a sign of many things, but that an affair is a definite possibility.
“It could easily be a sign of cheating,” she says. “The person is no longer feeling bored and dissatisfied. ”Instead, they are feeling alive and want to look their best.”
“Any time your partner makes a change in front of you, don’t sit back and let it go,” she says. “If out of the blue your partner is no longer a couch potato, you should want to know why.”
http://gma.yahoo.com/blogs/abc-blogs/beware-partner-sudden-interest-fitness-220400464.html

Yanno, I'll never understand science's need to say that something just can't be true under any circumstances unless there's a scientific study done on it.
Sigh.
But what that study seems to ignore that it could also be an indication that a person is taking more interest in their partener and simply wants to impress them even more. Sometimes we do want to be trimmer and slimmer for out significant other so that we can make love to them better, do we not?
But not according to science! Oh no!
So, the big flaw to that article is that it is generalizing things.