Suffering from cravings, constant hunger, depression or fatigue? What's really eating you could be poor nutrition.

Problem #1: Low energy/fatigue

Cause: A low-carbohydrate weight-loss diet could be the culprit. Skimping on carbs, the body's prime source of immediate fuel, may leave you physically tired and mentally sluggish. Other possibilities: not getting enough iron or water.

Solution: Eat plenty of complex carbs to stay energized and mentally sharp while still losing weight. Add iron-rich foods such as oatmeal and spinach, and drink at least eight glasses of water daily.

Best foods to eat: Chicken and vegetable stir-fry over brown rice; chili with beans; black-bean-and-Wehani-rice salad; whole-grain cereal with fresh berries; brown rice pilaf with pine nuts; whole-wheat noodles with Asian sauces; extra-lean red meat.

Problem #2: Feeling down/depressed

Cause: Not getting enough omega-3 fats from fish or enough B vitamins, especially folic acid, vitamin B6 and vitamin B12, could make you feel down in the dumps.

Solution: Eat two to three weekly servings of fish to get your omega-3s and vitamin B12; two dark-green leafies or legumes a day for folic acid, and several foods rich in vitamin B6 like bananas, whole grains, asparagus and legumes.

Best foods to eat: Seafood chowder with whole-wheat crackers; whole-wheat pita with smoked salmon, cranberry or honey mustard, fresh spinach and pineapple; vegetarian chili; black bean soup; lentil salad; grilled trout fillets; Cajun chicken wrap with cucumbers and tomatoes; peanut-butter-and-sliced-banana sandwich on whole-wheat bread.