Weight gain during pregnancy

What and how you eat during pregnancy will affect your child's future health. You can protect your health and the health of your growing baby with a healthy diet. During pregnancy, you'll need extra calories, protein, vitamins, and minerals. The proper foods will give your body the energy and nutritional resources it needs to support the developing fetus.

Pregnancy is a time of "extras": extra tender love and care for you and your new life inside, and extra weight! How much weight do you need to gain? Put it this way: pregnancy is not the time to lose weight or diet. During your pregnancy you should aim to gain about 25 lbs to 35 lbs (11.4 kg to 15.9 kg), although this might vary depending on your pre-pregnancy weight and whether you are carrying twins or multiples.

Your weight gain during pregnancy likely will not be steady at first. Most women typically gain between 3 lbs and 4 lbs (1.4 kg to 1.8 kg) during the first trimester. You should gain weight slowly but steadily during the last half of your pregnancy. A good rate of weight gain after the first trimester is approximately one pound (0.45 kg) each week.

Keep in mind that these are average figures for women who were at a healthy weight before pregnancy, so if your weight-gain pattern is different, it doesn't necessarily mean anything is wrong. Ask your doctor or a registered dietitian about what is an appropriate weight gain during pregnancy for you.

Keep in mind the following tips:

  • Your weight before pregnancy will determine what is considered a healthy weight gain for you during pregnancy. While weight gain is normal during pregnancy, you should contact your doctor if you experience any sudden changes (gains or losses).
  • Dieting is strongly discouraged during pregnancy, as it may be harmful to the development of the baby.
  • You should choose from a variety of healthy food options to ensure you are getting the best nutrition possible.

Nutritional variety and important nutrients

The Dietitians of Canada suggest that, like all Canadian women, if you are pregnant you should choose a variety of foods daily from the four food groups: grain products, vegetables and fruit, milk products, and meat and alternatives.

Choosing foods from each of the four food groups of Canada's Food Guide to Healthy Eating can help you meet your special nutritional needs. It is important to eat regularly and enjoy nutritious snacks. The guidelines suggest that you eat three meals and three snacks daily. These should include:

  • milk products: 3-4 servings (1,200 mg of calcium daily)
  • grain products: 5-12 servings
  • fruits and vegetables: 5-10 servings
  • meat and alternatives: 2-3 servings (60-75 g of protein daily)
  • others: in moderation (e.g., sweets, condiments, dressings, deep fried or fast foods, commercially baked goods)

Important nutrients for you and baby

Nutrient or Vitamin What is it for? Where can I find it?
Iron Healthy blood cells and adequate oxygen supply Lean red meat, dried peas and beans, whole grains, enriched cereals, dark green vegetables, dried fruits and nuts
Folate/folic acid* Brain and nervous system development, healthy blood cells Dark-green leafy vegetables, dried peas and beans, cantaloupe, orange juice, grapefruit, nuts
Calcium Protects bones and teeth, and helps reduce high blood pressure Milk & milk products, sesame seeds, almonds, blackstrap molasses, fortified soy milk, soy beans, broccoli, turnip
Zinc Building and healing tissues (baby tissues too!) Meats, whole grains, nuts and seeds, milk products
Vitamin A Overall growth and development, vision and immune system Orange and dark green fruits and vegetables, meat, eggs, cheese
Vitamin D Helps calcium in protecting and building strong, healthy bones and teeth Sunlight, milk and milk products, eggs
Vitamin B12 Makes new cells (especially blood cells) and builds a healthy nervous system Lean meats, certain fish**, eggs, milk, hard cheeses, fortified breakfast cereals, soy products
Vitamin C Strengthens the immune system and helps build healthy tissues Citrus fruits, vitamin-enriched apple juice, green vegetables, tomato juice
Essential fatty acids Development of the brain and nervous system, hormone production, and vision Soybean, canola oils and non-hydrogenated margarine, some soy-based products (e.g., tofu)
Protein Builds, repairs and replaces tissues; maintains fluid balance and immune system; aids in blood clotting Lean meats and poultry, combined grains and legumes, seeds, nuts, and egg and milk products***
*Do you have a female relative or friend wanting to conceive? Make sure she knows about the importance of folic acid before she gets pregnant.
** For a list of certain fish and other foods to avoid during pregnancy, see "What foods or substances should I avoid?" in this health feature.
*** For pregnant women who follow a vegetarian diet, see "Vegetarianism During Pregnancy" in this health feature.

Folic acid is a member of the B-vitamin family. It acts with vitamin B12 in making red blood cells. Folic acid helps reduce a baby's risk of developing a type of birth defect called neural tube defect, or spina bifida. Neural tube defects happen early in pregnancy, often before a woman even knows she is pregnant. Make sure you get enough folic acid daily before you become pregnant. Since it's hard to get enough from dietary sources alone, most doctors recommend that healthy women take 0.4 mg (400 µg) of folic acid every day for several months before becoming pregnant as well as during pregnancy. Make sure the supplement contains no more than 1 mg of folic acid, unless your doctor recommends otherwise.

Other tips to increase folic acid intake:

  • Choose fortified breads and cereals.
  • Eat more foods rich in folic acid/folate: reach for asparagus, broccoli, spinach, oranges, legumes, nuts, and seeds.
  • Avoid overcooking vegetables.

How many extra calories do I need while pregnant?

During pregnancy, your basal metabolic rate (BMR, or the number of calories you use each day) will increase, and you'll need more calories to support the extra work needed for fetal development. During the first trimester, most women usually don't need to increase their usual daily intake of calories (i.e., 1,800 to 2,000 calories) unless they need to compensate for starting a pregnancy underweight. But even if extra calories aren't consumed in the first trimester, you should still make balanced nutrition part of your daily wellness plan.

During the second and third trimesters, you will need an extra 200 to 300 calories each day. But that doesn't mean feeling uncomfortably full: for example, just one piece of toast and a banana can supply those extra calories.

There are exceptions to the extra-calories rule: women who start out under- or overweight, women who are very physically active, and women with certain medical conditions should talk to their doctor about specific caloric needs.

Choose healthy foods to supply calories instead of high-fat or high-sugar alternatives. For example, if you like sweetened snacks and beverages, remember that fresh and dried fruits, and fruit juice concentrates, are sweet but also contain important vitamins and nutrients (unlike some other high-sugar snacks). The occasional ice cream treat is OK, but note that enjoying a cone or small bowl of low-fat yogurt is a more nutritious way to obtain dietary calcium.

Women with diabetes should talk to their doctor or a registered dietitian about their special nutritional needs during pregnancy. Women who are pregnant and have diabetes should carefully monitor their blood sugar levels to make sure the levels remain within the normal range. Women with blood sugar levels that are too high risk having a difficult birth. They also risk having babies that weigh more than normal at birth and have various newborn problems.

Women who did not have diabetes before may also develop the condition during pregnancy. This kind of diabetes is known as gestational diabetes. Most women with gestational diabetes can control their condition with a healthy balanced diet and moderate exercise. Medications are usually not necessary. Gestational diabetes usually disappears after the baby is born.

Will I require vitamin or mineral supplements during pregnancy?

Consult your doctor or dietitian - you might need to take a vitamin supplement during pregnancy. Keep in mind that supplements are meant not to replace foods, but to balance a nutritious diet. Your doctor can help you choose an appropriate supplement that contains suitable amounts of vitamins and minerals. Any supplementation that exceeds the recommended daily intake (RDI), such as folic acid, should be taken only under the recommendation of your doctor, because high doses of vitamins and/or minerals can be toxic at certain levels.

A folic acid supplement of 0.4 mg per day should be taken by healthy women (for several months in advance) who are planning to become pregnant and by women who are pregnant. A 1 mg daily dose of folic acid is standard during pregnancy and can be found in most over-the-counter prenatal vitamins.

In the later stages of pregnancy, you require more iron, to help produce healthy red blood cells for you and your growing baby. Sometimes it's difficult for women to consume enough iron from foods. Most doctors recommend that pregnant women take a daily iron supplement of 30 mg to 60 mg of elemental (ferrous) iron in addition to any other prenatal vitamins. Anemic women in particular may require an iron supplement. Discuss the possible need for iron supplementation with your doctor and pharmacist. You can also help your body better absorb dietary iron by eating iron-rich foods together with foods rich in vitamin C, such as berries, tomatoes, sweet peppers, and citrus fruits. For example, have a glass of orange juice with an enriched breakfast cereal.

Consuming 3 to 4 servings of dairy products can help ensure adequate calcium (i.e. 1,200 mg daily) during your pregnancy. However, women with diets lacking in calcium (e.g. women with a lactose intolerance) may require a calcium supplement in addition to their dietary sources. Look for calcium supplements that contain calcium carbonate because they have the most calcium per weight. Try to take calcium supplements between meals or at bedtime to increase the effectiveness of their absorption. Avoid bone meal and dolomite, as these types of calcium supplements may contain traces of lead. Talk to your doctor, pharmacist and dietitian for more information about calcium supplements, and be sure to incorporate calcium-rich foods in your diet.

What foods or substances should I avoid?

Caffeine: Caffeine crosses the placental barrier into the baby's blood when you are pregnant or breast-feeding. Limit your caffeine intake to less than 300 mg in one day. (One cup of coffee contains about 150 mg of caffeine, one cup of strong black tea contains about 100 mg of caffeine, and one 355 mL can of cola contains 36 to 46 mg of caffeine.) Watch out for the new "energy" drinks - while some contain only as much caffeine as a cup of coffee, others may contain much more. Energy drink manufacturers are not required to list caffeine on the drink label unless the caffeine is added as a separate ingredient. However, caffeine in energy drinks usually comes from natural sources, such as guarana or yerba mate, so the label may not tell the whole story about how much caffeine is in the drink. If you need a soothing cup of something warm, choose citrus, ginger, or lemon herbal teas (no more than two or three cups per day), soup, warm milk, or the occasional cup of hot chocolate. Consume caffeinated beverages in moderation, and drink them between meals, as they may interfere with the absorption of iron at meals.

Alcohol: Alcohol crosses the placental barrier and can cause fetal alcohol syndrome and permanent birth defects, especially if consumed in high quantities. The Motherisk Program states that most organ development is completed a few weeks after the first trimester. Brain development continues throughout pregnancy and after birth. Exposure to alcohol any time during pregnancy can affect the baby's brain.

The Canadian Health Network states that researchers are unsure if a "safe" level of alcohol consumption exists during pregnancy. The harmful effects of alcohol vary with the stage of pregnancy and the amount consumed on each occasion. However, research does show that all types of alcoholic beverages have the same negative effects during pregnancy. Avoid all alcoholic beverages if you are planning a pregnancy and while you are pregnant.

Nicotine: Smoking during pregnancy increases the risk of a baby being born prematurely and underweight. Stop smoking if you are considering getting pregnant; if you are pregnant, never smoke. Because of the health risks associated with second-hand smoke, avoid any smoky environments.

Medications: Illicit drugs, inhalants, prescription and over-the-counter medications, and even certain herbal products can affect the unborn baby. Check with your doctor or pharmacist before using any medications and herbal products.

Some artificial sweeteners: Aspartame, sucralose, and acesulfame-potassium are used in many foods such as soft drinks, desserts, yogurt, fruit spreads, salad dressings, chewing gum, and candy. Although evidence shows that these artificial sweeteners are safe for pregnant women, use them moderately. Avoid using saccharin or cyclamates.

Fish and shellfish: Certain fish may contain high levels of mercury, which can affect the baby's developing nervous system. Avoid swordfish, marlin, and shark. Limit your intake tuna or salmon to two medium-sized cans of salmon or light tuna, one medium-size can of albacore tuna, or one fresh tuna steak per week. Avoid raw or undercooked shellfish such as oysters, mussels, prawns (shrimp), and crab. These may cause severe food poisoning if contaminated by bacteria.

Milk and milk products: Avoid unpasteurized milk and cheese. This includes cheeses such as feta, brie, Camembert, blue cheeses, and goat cheese. These foods may contain bacteria called listeria, which are harmful to unborn babies.

Raw sprouts and unpasteurized juices: Avoid raw vegetable sprouts (such as alfalfa, clover, and radish) and unpasteurized fruit and vegetable juices, as these may contain bacteria such as Salmonella and E. coli. These bacteria can cause serious illness in pregnant women and may also be passed on to the baby.

Raw or undercooked meats, poultry or eggs: Undercooked meat, poultry, and eggs can contain bacteria and parasites that can harm an unborn baby. Be sure to cook ground beef and pork to at least 160° F (71° C), roasts and steaks to 145° F (63° C), whole poultry to 180° F (82° C), and eggs until the yolk and white are firm, not runny.

Certain meats: Avoid meat patés, and all liver products because of the risk of listeria. Liver and liver products are rich in vitamin A, and high levels of vitamin A may also be harmful during pregnancy.

Prepared foods: Avoid ready-to-eat meats such as deli meats, patés, and hot dogs. Also avoid ready-to-eat dressed salads (e.g., potato salad or coleslaw) and packaged salads. These foods may contain listeria.

Vegetarianism during pregnancy

Pregnant women who are vegetarian can still enjoy a carefully planned vegetarian diet. There are many health benefits to vegetarian diets, but women who are pregnant need to take extra care to get enough protein, iron, zinc, and vitamin B12.

Protein is essential to promote normal fetal growth, so it is an important nutrient for a healthy pregnancy. The recommended daily allowance (RDA) for women and men is 0.80 grams of protein per kilogram of body weight per day. During pregnancy, most doctors suggest women increase their daily protein intake by 6 grams (about the amount in one 250 mL glass of partly-skimmed milk, one cup of broccoli, one egg, or one-third cup of dry-roasted almonds). Vegetarian sources of protein include grains, legumes, seeds, nuts, and egg or milk products. Keep in mind that the protein in vegetables is less concentrated and less easily absorbed so you may need more or larger portions to get the required amount of protein.

The Vegetarian Food Guide published by the Dietitians of Canada suggests that pregnant women consume the following amount of these foods daily:

  • vitamin B12-rich foods: 4 servings
  • beans/nuts/seeds: 7 servings
  • calcium-rich foods: 8 servings

What about vegans? The Alberta Health and Wellness During Pregnancy Guide states that vegan diets can be low in calories, iron, zinc, vitamin B12, B6, calcium, and vitamin D. If you are vegan, talk to your doctor or a dietitian about ensuring you get enough essential nutrients during pregnancy.