Do you live with an overweight partner? Nearly two-thirds of Americans do, and it can be challenging on several levels. You want to try and change him or her—especially because excess weight puts your loved one at risk for heart disease, diabetes and stroke. But I've found from personal experience that nagging and criticizing doesn’t work. It's more effective to let your partner know that you love and support him or her, and that you hope for a long, healthy, adventure-filled life together. Here are eight secrets to help an overweight partner adopt a healthier lifestyle.

1. Change what's in your kitchen. Get rid of temptations. Fill up the fridge with ready-to-eat fresh fruit—apples, strawberries, red grapes, pineapple chunks and clementines are good choices. Popcorn is great for mindless TV munching. Low-cal frozen dinners are a must for emergencies.

2. Take walks together. No need to join a gym or buy a set of weights. Invite your partner for a sunset walk around the neighborhood. It's great for the heart—and your relationship.

3. Convert favorite dishes into healthier versions. Make sure you still have favorite meals—only healthier versions of them. If you're not the chief cook and bottle washer in the house, tell your spouse you want to help. Steam, bake or broil instead of fry. Use nonfat chicken broth to cook with instead of butter. For every unhealthy ingredient, substitute a healthier one.

4. Eat out less. When changing eating habits, it's easier to control portions and ingredients when you prepare the food yourself. Cook at home, and encourage your partner to take healthy food from home to have for lunch and snacks during work.

5. Give him or her positive affirmation. Once a day, make your spouse feel valued. A small gesture such as a spontaneous kiss or a squeeze of the hand acts as an enormous psychological boost, and sends your partner the message they are loved.

6. Get blood work done. If you two haven't done it in the past year, get complete blood work done—including diabetes and cholesterol tests. If there's a medical issue, pledge to work on it together. Health threats make good motivators.

7. Compliment your spouse on his/her progress. Let your loved one know that you notice and admire the hard work he or she is doing to change. Don't overdo it, but do remind your partner that you're still there rooting for his or her success.

8. Be a role model. If your loved one is overweight but you're not, you'll inspire him or her by looking great, feeling sexy, being energetic and following the same eating and exercise habits you'd like your partner to adopt. Seeing your healthy behaviors and their positive results will make them want to do those behaviors too.

Dr. Ro ( www.everythingRo.com) is Nutrition Advisor for The Today Show and Nutrition Contributor to NPR. Named by More magazine one of this country's top five nutritionists, Dr. Ro is America's best-known African American health expert, and the author of the best-selling "Dr. Ro's Ten Secrets to Livin' Healthy" (Bantam, 2007).