10. Eat as healthfully as possible every day.
It's OK to occasionally eat high-calorie, low-nutrient foods. Just not too often, and not too much.
"I tell people to eat as well as possible during the week, but on Saturdays to eat favorite foods in moderation. This model gives people something to look forward to and seems to help them stick to healthy eating habits," says Stephen Ball, PhD, associate professor of exercise physiology at the University of Missouri.
Look at the big picture of your eating habits, rather than obsessing about every morsel at every meal.
For instance, a meal that only consists of salad and a slice of whole grain bread may be short on protein. But you can make it up with other meals or snacks, says Susan Bowerman, MS, RD, CSSD, assistant director of the UCLA Center for Human Nutrition.