If you're trying to lose weight, build a healthy lunch with these 3 ingredients.

Just as breakfast gives me a much-needed energy boost in the morning, eating lunch fuels the second half of my day-and helps me stay away from the vending machine mid afternoon.
But when you're trying to lose weight, every meal-and calorie-counts. (Find out how many calories you should be eating to shed pounds here.) You can build a light but filling lunch with these three healthy ingredients-whether you're brown-bagging it or eating out.

-Brierley Wright, M.S., R.D., Nutrition Editor

1. Vegetables

Making vegetables the largest portion of your lunch boosts your lunch's total nutrition (vegetables deliver disease-fighting phytochemicals and essential vitamins and minerals) and gives you a healthy dose of fiber-a must-have when you're dieting. Why? Fiber helps you stay satisfied longer, plus research shows that upping your fiber intake may help promote weight loss. Find low-cal, high-fiber lunch recipes here.

2. Lean Protein

Adding a little lean protein to your lunch (think: tofu, chicken, fish or beans) is an easy way to stay satisfied throughout the afternoon-gram for gram, protein will keep you feeling fuller longer compared to carbohydrates and fat. Pack in the protein with these high-protein, low-cal lunch recipes.

3. Whole-Wheat Bread

Eating whole-wheat bread in place of refined white bread may help you trim your total body fat, as well as that much-hated belly bulge. A study in the Journal of Nutrition showed that people who ate about 3 servings of whole grains a day had about 2.4 percent less body fat and 3.6 percent less abdominal fat than those who ate barely any whole grains at all. Aim for at least three servings of whole grains daily (a slice of whole-wheat bread equals one serving). Other great sources: whole-grain cereal, oats, bulgur, quinoa and brown rice.