Gaining weight is an important part of your pregnancy. According to W. Allan Walker and Courtney Humphries, authors of "The Harvard Medical School Guide to Healthy Eating During Pregnancy," gaining the right amount of weight will help you have a healthy pregnancy and will help your baby grow and develop right on track. During your third trimester you should gain about one pound per week by adding 300 extra calories to your daily diet.
Low-fat string cheese can provide about 100 additional calories towards your extra 300 per day. String cheese contains a good amount of protein and calcium, which you and your baby need to remain healthy. A sufficient amount of protein ensures that your baby contniues growing normally as you approach your due date. Bridget Swinney and Tracey Anderson, authors of "Eating Expectantly: A Practical and Tasty Guide to Prenatal Nutrition," note that your baby gains about a half a pound each week towards the end of your pregnancy, and eating nutritious protein-rich foods, like string cheese, will help your baby reach this goal. Calcium is essential for the strength of your baby's growing bones, and string cheese supplies a good portion of what you need each day.
Breakfast cereal is a good source of fiber and calories, note Walker and Humphries. A bowl of cereal will supply between 120 and 200 calories towards your daily goal of an extra 300 calories, and it will also supply fiber and several important nutrients. A high-fiber cereal, such as bran flakes, will keep your digestive system working properly, which may help you avoid constipation, a common complaint during pregnancy. A bowl of cereal with skim milk will supply about 300 calories without adding a large amount of fat to your diet. Add a sliced a banana or a few blueberries will increase the nutrients with just a few more calories.
A snack or meal that includes a serving of turkey will help you reach your 300 additional calorie mark and will supply protein as well, note Swinney and Anderson. Eating lean turkey is an effective way to add the extra calories that you need to gain weight during your third trimester, but it does not contain so much fat that is an unhealthy food addition. A turkey sandwich on whole wheat bread will weigh in at about 300 calories and will supply protein and fiber. Swinney and Anderson also suggest rolling a piece of lean turkey in a tortilla with a slice of low-fat cheese. Adding a serving of shredded turkey to a salad is another way to add extra calories to your third trimester diet.