There is an association between low birth weight and the mother’s nutrition status. If a mother is underweight at the time she becomes pregnant and does not gain sufficient weight, there is an increased risk that the mother and baby will be malnourished.
It has been observed that girls born from mothers who were malnourished have lower body weights and poorer health outcomes than those born from normal weight mothers. This puts these girls at a higher risk for being malnourished as mothers if they become pregnant. Fortunately this situation can be avoided if the mother gains sufficient weight during pregnancy. Achieving a normal weight during pregnancy will improve the health of the mother's children, who will then be more likely to give birth to healthy children themselves. 
How much weight should a mother ideally gain during pregnancy?
Gaining the right amount of weight during pregnancy is important. Eating a balanced diet with sufficient calories will ensure that your baby is getting all the nutrients he/she needs to grow and develop at an appropriate rate.
Be sure to discuss with your health care provider how much weight you should gain during pregnancy.
- A woman of average weightbefore pregnancy should gain 25 to 35 pounds during pregnancy.
- Underweightwomen should gain 28-40 pounds during pregnancy.
- Overweightwomen may need to gain only 15-25 pounds during pregnancy.*
- Obesewomen should gain no more than 15 pounds during pregnancy.*
You may need to gain more or less weight, depending on what your health care provider recommends.
In general, you should gain about 2 to 4 pounds during your first 3 months of pregnancy and 1 pound a week for the remainder of your pregnancy. If you are expecting twins you should gain 35 to 45 pounds during your pregnancy. This would be an average of 1½ pounds per week after the usual weight gain in the first 3 months.
*It is neversafe to lose weight during pregnancy--both you and your baby need the proper nutrients in order to be healthy.
Important nutrients
During pregnancy, you need more nutrients and energy because your body is supporting the development of the placenta, increased blood volume and fat stores, that support the baby developing in your uterus.
Your needs will depend on many factors including your pre-pregnancy weight and your physical activity. You will also need more vitamins and minerals, especially vitamin D, folic acid, iron and calcium. Below are some general guidelines you can follow:
Calories
The saying that pregnant women are "eating for two" is not exactly true. Though pregnant women do need extra calories from nutrient-rich foods to help the baby grow, the amount of extra calories needed to meet those needs is only about 100 to 300 more per day above and beyond what was eaten prior to pregnancy.
Protein
An adequate supply of protein is generally provided through a balanced eating plan, there usually is no need to use high-protein beverages, supplements, or powders.
Lean meats, poultry, and fish are good sources of protein that also supply other necessary nutrients, such as iron, B vitamins, and trace minerals. Dried beans, lentils, nuts, eggs, and cheese are other high-protein foods.
Folic acid, calcium, and iron
- Folic acid: Pregnant women need to be sure to get 400 mg of folic acid per day, which is possible by diet alone (sources include leafy green vegetables, legumes, seeds, and enriched cereals/grains). If a woman is unsure she is getting enough in her diet, most multivitamins do contain 400 mg of folic acid.
- Iron: Since it is difficult for pregnant woman to meet their increased iron needs, it is almost always necessary to take pre-natal vitamins containing extra iron. Your health care provider will provide guidance on choosing the right pre-natal vitamin for you. You can still try to get iron from foods. Red meat is particularly rich in iron. Fish and poultry are also good sources. Enriched and whole grain breads and cereals, green leafy vegetables, legumes, eggs, and dried fruits also provide iron.
- Calcium: Foods high in calcium are: yogurt, cheese, milk-based desserts, calcium fortified tofu and soy milk, soybeans, green leafed vegetables, oranges and seafood such as oysters, mussels and salmon.
Dietary supplements
Dietary supplements come in many forms (powders, pills, liquid formulas, snack bars etc.) and contain a varying mix of ingredients and nutrients (calories, protein, fat, vitamins, and minerals). It is important that you discuss any dietary supplements you are taking, or wish to take, with your health care provider. Explain to them the reason you are taking them, or why you want to take them.
Many women are able to fulfill most of their nutritional needs through the foods they eat. Some women struggle with tolerating regular foods, and may want to try supplements.
Each individual pregnancy is different, and thus it is not possible to give standard recommendations to all expecting moms about dietary supplements. Keep your health care provider informed during your pregnancy of how you are doing, and any desires you have to add any supplements to your diet.
Other general recommendations:
- If you're lactose intolerant, don't worry. There are many products that are prepared without lactose. Some people tolerate lactose-containing products if consumed in smaller portions. You can also substitute lactose products with yogurt which is more tolerable for some people.
- Eat whole wheat bread and cereals as they are high in fiber.
- Be sure to drink enough liquid, such as water, milk, and fruit juices to prevent constipation (common during pregnancy) and dehydration. Though there are no specific recommendations for the amount of water to drink, many sources indicate ~2-3 liters is what we should drink daily to replace fluids lost. You should drink enough so that you don't ever feel thirsty, and your urine should be colorless or only slightly yellow. Keep in mind that in addition to pregnancy, a hotter climate, exercise, and illness can increase the amount of liquids you need.
- Consume about 5 servings of fresh yellow or green fruit and vegetables that are high in vitamins and minerals, especially iron and folic acid.
- Beans, peas, and lentils are rich in iron, but try to eat them with a source of vitamin C, such as fruit juices, lemons or oranges for better absorption.
- Eat all types of meat, poultry and fish. However, eat beef and pork in moderation.
- Fats and sweets are sources of concentrated energy and they increase calories. If you're overweight, avoid them.
- Lastly, it is recommended that you snack twice a day to increase your calorie intake and maintain your energy and blood sugar at the right levels.
