The wish for a bikini body motivates many a summer diet. But if your beach body dream came true, how would your mate feel? The answer to that question may well affect your progress-whether you're aware or not.

For now, let's set aside the issue of whether or not it makes sense to diet for a short-term goal, like a "bikini body". It usually doesn't. However, our mates' responses to our efforts to change--how we care for ourselves, how we look-weave in and out of the change process itself, no matter how or when it occurs. So, it helps to pay those responses some attention.

When I first asked Ellen, for example, if her husband was supportive of her doctor-recommended weight loss efforts, she said, without hesitation, "Oh yes, he's very supportive." As we talked more, though, it emerged that he pushed for restaurant meals at least four times a week. This made eating healthfully very challenging for Ellen. While she, and their children too, argued for more meals at home, her mate insisted that this helped him relax. Exploring how this was not supportive, she found herself extremely uncomfortable with the idea of "making a bigger deal out of this."

Rhonda's fiancé, on the other hand, was fine eating at home. But he continued to bring home Kisses, M&M's, and peppermint patties by the bagful, "Because he knows I love them." Did he realize how important changing her diet was for her? "Yes," Rhonda was sure....."it's just that he knows I love that stuff. He likes to make me happy." While some dieters are angered by these kinds of gifts, Rhonda had trouble seeing it as sabotage and didn't want to hurt her mate's feelings.

What's going here? For starters, some partners need to be told specifically how they can be supportive. Trying to make a change for the better often requires us to be assertive about our needs, and about how we want others to help. If you have trouble asserting yourself , that, in itself, can make change efforts, especially tough ones like diet overhauls, hard indeed.

Just as likely, though, these partners may have been acting on-possibly unacknowledged-feelings about their loved ones changing. She may think, "I'll be thinner....better-looking....in control.....I'll feel great!" He may think, "What if she does become thinner....better-looking....more in control....?" He may find himself feeling a little anxious about those possibilities. Will she still need him? Want him? Will she be a pain to be around? These are not thoughts and feelings that one feels proud of. And yet, if ignored, they can motivate those urges to make a dieter "happy" by bringing home chocolate or cheesecake. In other words, a partner's anxiety can blur his or her ability to get solidly on board with efforts to change.

Furthermore, couples generally tune into each others' feelings. And often we wish to spare the other discomfort. So: you're trying to change how you eat. Your mate signals, however subtly, that this causes discomfort (that chocolate, or that dinner invitation, for example). This may mark the beginning of the diet's downfall. Not only because of the chocolate itself, but also because there's suddenly someone else's feelings, and possibly a relationship "issue" to confront. Your resolve starts to falter. You blame it on the food, or on willpower. Maybe you can't do it after all.

Many partners, of course, do offer strong support for the others' goals. Any many would really wish to, if they knew how. Even those who apparently sabotage, as described here, may genuinely want their mate to succeed and be happy. It's just that we often can't help feeling some anxiety as a loved one changes. And what each member of a couple does has some effect on the other.

The solution usually lies in thinking about, and discussing, what each feels about the new undertaking. If your spouse fears you'll attract new attention with a new body, for example, he or she may need reassurance. And even when complete reassurance isn't possible, airing the doubts and discomforts has a way of deflating the witting or unwitting sabotage.

Statistically, married and partnered people are more likely to gain weight than singles. There are many reasons for this, including reduced incentive to stay slim, and reduced activity levels, in addition to the kinds of emotional complications I point to here. At the same time, having a supportive "teammate" as you try to change can increase your chances of success, both in the short and long terms. So checking in on your spouse's feelings, and on your feelings in reaction, will help your weight. It may also benefit your relationship overall....and this insures all kinds of better things, including keeping your weight healthy into the future.