Let's do lunch — the healthy way

From fast-food restaurants and delis exploding with high-calorie sandwiches to salad bars stocked with high-fat and high-sugar add-ons, lunchtime can be a minefield of temptation for those trying to eat a healthy and balanced diet.

But a healthful — and enjoyable — lunch can be done. These simple tips can help.

This week-by-week plan will help you transform your eating habits into a program of nutritious and delicious food choices that can last a lifetime. Applying the latest results from nutrition science, Harvard experts take you by the hand and guide you to create an eating plan to improve heart health, longevity, energy, and vitality.

Your meal should include lean protein, whole-grain carbohydrates, and produce. Roughly half of your plate should be vegetables or fruit; one-quarter should be lean protein such as fish, chicken, turkey, tofu, beans, or low-fat cottage cheese; and one-quarter should be whole grains, such as one slice of whole-grain bread, or half a cup of brown rice, whole-wheat pasta, or quinoa. You might include a small amount of healthy fat, such as a tablespoon of oil-and-vinegar dressing on your salad.

Salad can be a good way to go, but you need to be careful. Regular salad dressings, cheeses, and salads that are mayonnaise-based (such as tuna, chicken, and egg salads) can contain unhealthy fats, hidden sugar, and salt — not to mention lots of calories. Here's the trick to a healthy and satisfying lunch salad:

Step 1: Build a vegetable base. Load your plate with leafy greens and raw or grilled vegetables.

Step 2: Add some protein. You might try a few scoops of garbanzo or kidney beans, for example. Beans are an excellent source of fiber — and they're filling! Other good selections include grilled chicken, low-fat cottage cheese, or chopped eggs. But go light on any cheese toppings — just a sprinkle of a strongly flavored variety like feta or Parmesan can deliver flavor with fewer calories.

Step 3: Add a small amount of healthy fat. Sprinkle on the nuts and seeds. They are high in heart-healthy unsaturated fat and healthy protein, give you a feeling of fullness, and help food stay in your stomach longer. You might also opt for a dash of oil and vinegar.

Step 4: Whole grains and fruit make a nice addition to a creative salad. Look for whole grains like barley or bulgur wheat to sprinkle on top. Or add a few slices of fruit.