The first foods to avoid are processed meats from hot dogs to deli cold cuts, including salami and bologna. Even those labeled "low calorie" are likely to have questionable preservatives, such as salts and nitrates. Studies show that these are the worst types of meats for your heart.
Try freshly prepared turkey and chicken instead. In a hurry? A rotisserie chicken cooked at your favorite health food market is a good alternative.
Next, pass on processed foods made with refined flour. These include typical breakfast cereals, white breads and similar baked goods. For the most nutrition, look for stone-ground whole-grain breads and steel-cut oats.
Substitute a mashed slice of avocado for typical sandwich spreads. You'll get great taste and great nutrition.
Instead of bagged chips and other packaged snacks, crunch an ounce of nuts. For only a slight difference in calories, you get protein, health fats and fiber.
Bottled salad dressings--even diet or low-fat versions--often have corn syrup along with many additives. Whisk up your own vinaigrette with extra virgin olive oil and vinegar, or try nonfat yogurt with lemon juice, herbs and garlic.
If you're short on time during the week and can't cook, set aside a couple of hours on the weekend to make a few dishes that will last all week, like roasted turkey breast, salsa with fresh tomatoes and a stockpot of vegetable soup--far healthier than salt-filled canned varieties.