How to get fit, not fat: That's the question ; Q&A
by Nanci Hellmich. USA TODAY

A better Life; Health, education & scienceUSA TODAY's annual diet series began on Monday with a look at the carb-counting craze and continued Tuesday with tips on cutting calories and exercising more. Today, USA TODAY's Nanci Hellmich profiles an Ohio couple on the South Beach diet. Also, an excerpt from Tuesday's online chat.---

How do you stop the cycle of losing weight and regaining it? Should all carbohydrates be lumped together? What's the best way to start exercising? These were among the concerns of people who participated in USA TODAY's online chat Tuesday with three national nutrition experts. Some of the questions:

Q: I've lost weight on many different diets, but as time goes on, I always gain it back and sometimes end up weighing more than when I started. Am I a lost cause? -- Sarasota, Fla.

A: No, actually there are millions of other people like you who fall off their diets and keep gaining back the weight they worked so hard to lose.

Many popular diets set you up to fail because they give you false hope that simply adjusting the foods on your plate is all you need to do to lose weight. But weight loss is not just about carbs and proteins. It's also about how you cope with stress and being physically active. Having a multidimensional approach to healthy weight loss will stop your dieting merry-go-round. -- Robert Kushner, professor of medicine at Northwestern University in Chicago

Q: Fried foods, soft drinks and empty calories from candy or junk foods are the prime dietary culprits of obesity in the USA, not carbohydrates. The premise that carbohydrates are lumped into a huge category to be avoided is absolutely idiotic. Would you agree or not? -- Oklahoma City

A: You are absolutely correct. The primary cause of obesity is an overabundance of calories consumed and not enough calories being burned. Throw in the extra stresses of life and you have a perfect obesity storm. Treatment must be directed at these underlying habits, not banishing carbohydrates from our plates. -- Kushner

Q: I am overweight and can't get into the groove of working out. Can you give me advice on starting a new life with exercise in it? - - Petersburg, Texas

A: Start by making an appointment with your physician to have a complete checkup. Make a schedule of your typical day. Notice periods when you could be moving while you do other things. You can do modified squats from your desk chair while talking on the phone. Dedicate at least one-half day each weekend to some type of fun physical activity.

During the work week, follow this formula: For the first two to four weeks, if you are more than 50 pounds overweight, try to do two days a week of 20 to 30 minutes of aerobic-type activity that supports your weight, such as biking, swimming, circuit weight training. Gradually increase the number of days and minutes of exercise as your schedule permits, and after about three months or so begin adding some weight-bearing activities like walking or low- impact aerobic dancing.

If you need to lose 10 to 30 pounds or so, walking is a great first choice. Try to get a buddy to walk with you or join a martial- arts class. -- Melinda Sothern, an exercise physiologist and director of the Prevention of Childhood Obesity Laboratory at Louisiana State University

Q: I am 67 years young and notice that articles in magazines never seem to address this age category regarding fitness, dieting or weight loss. Any advice? -- Coconut Creek, Fla.

A: Good question. As you age, you need fewer calories to maintain a healthy weight because lean body mass decreases and your metabolism slows. But needing fewer calories doesn't mean you need fewer nutrients. It is important to get enough protein, because your body becomes less efficient at using this nutrient. Drink six to eight cups of water or fluids a day. By eating lots of fruits and vegetables, you will get your antioxidant vitamins A, C and E. This helps the immune system. -- Edith Howard Hogan, a registered dietitian in Washington, D.C.