If you want to improve your partner’s diet or exercise behaviors, make sure he’s paying attention to what you are doing. Research published in JAMA Internal Medicine shows people are more successful in swapping bad habits for good ones if their partners are making a change as well. “The study underscores the importance of social support in health,” says Susan Krauss Whitbourne, Ph.D., professor of psychological and brain sciences at the University of Massachusetts, Amherst, who did not write the study. “If you’re trying to get your partner to eat more fruits and vegetables and fewer unhealthy foods, then take them off your menu. If you’re the cook, control what you’re putting on your plate so you’re setting a good example.” Most important, she says, “Give your partner plenty of positive reinforcement for each step he or she takes toward a healthier lifestyle.”