Registered dietician Keri Glassman appeared on "The Early Show" Thursday to explain the relationship between exercise and weight loss.
Exercise is important, Glassman said, but it may negatively affect your weight loss for three main reasons:
1. Exercise makes you hungrier, causing you to eat more.
2. Exercise causes feelings of entitlement. You may want to reward yourself because you worked out so hard at the gym.
3. Exercise does not burn that many calories. Couple that fact with being hungrier and you may eat more calories than you burned.
To demonstrate the calorie intake versus exercise principle, Glassman noted these comparisons:
Elliptical training for 44 minutes/500 kcal burned=1 Honey Bran Raisin Muffin from Dunkin Donuts
Kickboxing for 25 minutes and 272 kcal burned=Grande Starbucks café late with whole milk
Jogging for 60 minutes and 470 kcal burned=1 slice (1/6 of cake) of Sara Lee Cheesecake, chocolate swirl NY style
Pilates for 30 minutes and 119 kcal burned=5 pieces of hard candy
So is exercise not worth it?
Glassman said exercise is worth it, if you use it to your advantage. "Good nutrition," she told CBS News, "is primary. Combine that with good exercise habits and you have a powerful combination."
She added exercise does help burn calories -- you just can't eat more because of it. Also, staying active in your daily life, she said, is important.
And since, exercise may trigger hunger, Glassman said, you need to focus on not only the calories you are consuming, but making sure the calories you do consume are going to fill you up. Foods high in fiber, protein and healthy fat, she said, are low enough in calories that you won't be sabotaging your workouts.
Glassman said you can beef up your workouts by doing weight-bearing exercises, too.
"This will help increase muscle mass," she said. "...In conjunction with the calories burned during exercise and being diligent about your diet, you can make a dent in your waistline."
And, Glassman said, don't forget all the other benefits of exercise, such as reducing your risk for cancer, heart disease and diabetes.
Glassman recommended these meals to help keep your eating habits in check:
1/2 cup oatmeal
1 cup blueberries
1 tbsp. chopped walnuts
Large glass of water
Turkey sandwich on whole wheat with avocado, tomato, mustard
Large side salad (romaine, broccoli, carrots, onions) with 1 Tbsp. vinaigrette
Large glass of water
Baked Sweet potato
6 oz. Roasted chicken or halibut
Sauteed spinach with 2 tsp. olive oil
Side salad with 1/3 cup chickpeas, cherry tomatoes and 1 Tbsp. lemon vinaigrette dressing