Nutrition and Weight Gain During Pregnancy

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Nutrition and Weight Gain During Pregnancy

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A balanced, nutritious diet during pregnancy is important to maintain your health and nourish your fetus. Be sure to increase your daily caloric intake by 300 calories after you become pregnant.

The average woman needs 2,200 calories a day and 2,500 when she is pregnant. If she is carrying twins, her need increases to 3,500 calories, and for triplets or more, she needs 4,500 calories.1 Talk to your doctor or a dietitian about your daily calorie needs because your needs depend on your height, weight, and activity level.

Your doctor may give you a nutrition plan to follow throughout pregnancy and while breast-feeding. You may also receive a prescription for a vitamin and mineral supplement or a list of recommended non-prescription supplements.

Eating a variety of foods can help you get all the nutrients you need. Your body needs protein, carbohydrate, and fats for energy. Good sources of nutrients are:

  • Unsaturated fats like olive and canola oil, nuts, and fish.
  • Carbohydrate from whole grains, fruits, vegetables, legumes (peas, beans, and lentils), and low-fat milk products.
  • Lean protein such as all types of fish, poultry without skin, low-fat milk products, and legumes.

Eating healthy foods during pregnancy is good for your overall health and for the health of your baby. You may already have a healthy diet, or you may need to make some changes to eat healthier.

Click here to view an Actionset. Healthy Eating: Changing Your Eating Habits
Click here to view an Actionset. Healthy Eating: Making Healthy Choices When You Shop
Click here to view an Actionset. Healthy Eating: Cutting Unhealthy Fats From Your Diet

It's also important to eat plenty of fruits and vegetables. These not only give you necessary nutrients but also help you get fibre. Planning your meals can help you add healthy foods to your diet.

Quick Tips: Adding Fruits and Vegetables to Your Diet
Meal Planning: Menu and Grocery List (What is a PDF document?)

Folic acid

Folic acid is a B vitamin. Taking folic acid before and during early pregnancy reduces the chance of having a baby with a neural tube defect or other birth defects.

  • Women who have no health risks should take a multivitamin that contains 0.4 mg (400 mcg) to 1 mg (1000 mcg) of folic acid every day.2
  • Women who are pregnant with twins or more should take 1 mg (1000 mcg) of folic acid daily.3
  • Women who have certain health risks need to take additional folic acid. These health risks include epilepsy, insulin-dependent diabetes, and obesity. These risks also include having a family history of neural tube defects or being in a high-risk ethnic group, such as Sikh. A daily dose of 5 mg (5000 mcg) of folic acid beginning at least three months before conception and continuing until 10 to 12 weeks after conception is recommended for women who have these risks.2 Do not try to reach this amount of folic acid by taking more multivitamins because you could get too much of the other substances that are in the multivitamin.4


You will need twice as much iron in your second and third trimesters as you did before pregnancy. This extra iron supports the extra blood in your system and helps with the growth of the placenta and the fetus. Your iron requirements are slight during the first trimester of pregnancy, and taking iron supplements in the first trimester may aggravate morning sickness.

After the first trimester, take a daily supplement containing 27 mg of iron (most prenatal vitamins include iron).5 A woman with a multiple pregnancy is advised to take 60 mg to 100 mg of iron daily.3 Iron supplements can cause an upset stomach and constipation. Taking your iron at bedtime may decrease the chance of stomach upset. Your body absorbs iron best in small amounts when you eat it with vitamin C, so you may want to take your iron throughout the day.


Calcium is necessary for the development of the fetus's skeleton. You can get enough calcium in your diet by eating or drinking 4 servings from the dairy (milk) group each day. Good sources of calcium from non-milk sources include:

  • Greens (such as mustard and turnip greens), bok choy, kale, and watercress.
  • Broccoli and cauliflower.
  • Tofu that is "calcium-set."
  • Corn tortillas made with lime.
  • Calcium-fortified orange juice.

Weight gain during pregnancy

The recommended weight gain for a woman of normal weight is 11.5 kg (25 lb) to 16 kg (35 lb). You can expect to gain more if you are carrying twins.

If you are overweight, your ideal goal is less than the average weight gain, 7 kg (15 lb) to 11.5 kg (25 lb). If you are underweight, it is best to gain 12.5 kg (28 lb) to 18 kg (40 lb).

For obese women, the Society of Obstetricians and Gynaecologists of Canada recommends weight gain of 7 kg (15 lb).6 Your doctor will work with you to set a weight goal that's right for you. For more information, see the topic Obesity and Pregnancy.

Ideally, you will gain weight slowly over the entire pregnancy:

  • Up to 2 kg (4 lb) during the first trimester
  • 0.5 kg (1 lb) a week during the second and third trimesters

If you stop gaining weight for more than 2 weeks, or if you gain weight faster than these recommendations, consult your doctor.



  1. Newman RB, Rittenberg C (2008). Multiple gestation. In RS Gibbs et al., eds., Danforth's Obstetrics and Gynecology, 10th ed., pp. 220–245. Philadelphia: Lippincott Williams and Wilkins.
  2. Wilson DR, et al. (2007). Pre-conceptional vitamin/folic acid supplementation 2007: The use of folic acid in combination with a multivitamin supplement for the prevention of neural tube defects and other congenital anomalies. SOGC Clinical Practice Guideline No. 201 (replaces No. 138). Journal of Obstetrics and Gynaecology Canada, 29(12): 1003–1013. Also available online:
  3. Cunningham FG, et al. (2010). Multifetal gestation. In Williams Obstetrics, 23rd ed., pp. 859–889. New York: McGraw-Hill.
  4. Cunningham FG, et al. (2010). Prenatal care. In Williams Obstetrics, 23rd ed., pp. 189–214. New York: McGraw-Hill.
  5. Panel on Micronutrients, Food and Nutrition Board, Institute of Medicine–National Academy of Sciences (2001). Dietary reference intakes: Recommended intakes for individuals, vitamins. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc, pp. 772–773. Washington, DC: National Academy Press.
  6. Wilson DR (2010). Obesity in pregnancy. SOGC Clinical Practice Guideline No. 239. Journal of Obstetrics and Gynaecology Canada, 32(2): 165–173.


By Healthwise Staff
Primary Medical Reviewer Sarah Marshall, MD - Family Medicine
Primary Medical Reviewer Brian D. O'Brien, MD - Internal Medicine
Specialist Medical Reviewer Kirtly Jones, MD, MD - Obstetrics and Gynecology
Last Revised August 9, 2011

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