I feel like i am underweight for my height...how can i gain about 5 pounds while i am workin out to just get my body toned up?

Check your diet: You can meet with a dietician to make a meal plan. Usually, you should have your metabolic needs estimated , taking into accout your activity level. Then you should track your food intake and calorie count using " my food advisor: http://tracker.Diabetes.Org/ or apps on your phone, if convenient. This would help estimate if your caloric intake is adequate. If not gaining weigth stil, see your md.

Eat healthy foods: high in calories. Eat 6 meals /day. Work on strength training to build large muscle groups. Work out w heavier weights w fewer repetitions. Sleep at least 8 - 9 hrs/night. Hydrate well w water. Foods to help w weight gain: almonds, cashews, pecans, sunflower seeds, flax seeds, walnuts, hummus, avocados, granola, trail mix, dried fruits, protein shakes & bars, lean meats, poultry, fish, smoothies