In our society today, there are many opinions about what we should eat in pregnancy. Our mothers would tell us to “eat up as you are eating for two” and of course, we are genetically programmed to listen to our mothers! If all pregnant women ate for two during their pregnancies however, we would put on so much weight that we would grow to be the size of a barn. As women already know, losing weight after delivery is just sheer hard work. So let’s have a look at a healthy diet and appropriate weight gain in pregnancy.

It is recommended that pregnant women should have a broad diet covering the five main food groups in pregnancy. Multivitamins are not strictly necessary if you eat a balanced healthy diet, however, there are exceptions to this. These exceptions are supplements that must be added to your diet when you are pregnant.

The first of these supplements is folate. Folate is essential for the development of the baby’s brain and nervous system. Many modern diets do not contain adequate folate and as such, folate supplementation is recommended to all pregnant women. In fact, anyone planning a pregnancy should commence Folate supplements (500mcg or 0.5mg daily) for 3 months pre-conception if possible, and then to continue it for the first 3 months of pregnancy. This has been shown to significantly reduce the risk of neural tube defects such as spina bifida. If you have not been taking it pre-conception, just start taking it when you find out you are pregnant.

Next is iodine which is a mineral needed for the production of thyroid hormone, also important for the growth and development of the baby. Iodine is essential for the development of the baby’s brain and nervous system. Inadequate iodine intake during pregnancy increases the risk of mental impairment and short stature in the newborn baby. Australians have been found to have insufficient iodine in their diets. As pregnant and breastfeeding women have increased iodine requirements, it is recommended that pregnant women take an iodine supplement of 150mcgs per day until they stop breastfeeding. In addition, rich sources of dietary iodine include seafood, seaweed, eggs, milk and dairy products.

Another important supplement is iron. Iron is an essential component of haemoglobin which is the oxygen-carrying unit in red blood cells. A woman’s blood volume is increased significantly in pregnancy hence the need for increased iron requirements in pregnancy. In addition to that, the baby also draws iron from the mother which it stores to last it through the first five or six months after birth. In the face of these increased iron requirements, anaemia is a common nutritional problem in pregnancy.

Iron deficiency anaemia can make you feel breathless and lethargic, and even cause you to have palpitations (a racing heart). As such, iron supplements may be needed by some women in pregnancy. It is important for women to eat iron-rich foods every day and dietary sources of iron include red meat, whole grain cereals and green vegetables. Iron absorption from these foods are improved when taken at the same time as Vitamin C.

Finally, calcium is essential to keep your bones healthy and strong. During the third trimester of pregnancy, your baby needs a large amount of calcium as it develops and strengthens its bones. Insufficient dietary calcium in pregnancy can lead to you developing osteoporosis in later life as the calcium that is needed by the baby is drawn from your bones. The recommended daily intake of calcium in pregnancy is approximately 1000mg daily. Each serve of dairy contains approximately 300mgs of calcium (e.g. A glass of milk, a slice of cheese or a tub of yoghurt is each a standard serve of dairy).

Now, let’s look at what to expect in weight gain throughout pregnancy. Steady weight gain is normal and quite important for the overall health of the mother and baby. The average weight gain for a healthy woman in pregnancy is approximately 11.5 to 16 kgs.

Being too underweight or too overweight can have negative effects on the pregnancy and birth of the baby. Underweight women may need to gain more weight in pregnancy (between 12.5 – 18kgs). If overweight, dieting is not recommended in pregnancy but the suggested weight gain is less (between 5-11 kgs).

So, how do we manage all this? When pregnant, a good approach is to eat to satisfy your appetite and monitor your weight. It is important to choose healthy foods from the five food groups, and limit discretionary foods and drinks high in saturated fats, added sugars and added salt. Moderate portion sizes are also recommended particularly in the third trimester as your digestion slows down. As a general rule of thumb, a standard dinner plate of half vegetables, a quarter protein and a quarter carbohydrates is an easy way to easily eyeball a healthy meal.

Some other tips for a healthy diet are to avoid high GI foods (such as rice, bread, potatoes and chips) and to choose low GI options where possible (If you can’t do without bread, go for the low GI options now available). Ensure adequate fluid intake of 2-3 litres of fluid daily, but avoid fruit juices and drinks high in sugar. Processed foods and foods high in saturated fats should also be limited. Oily fish is recommended in pregnancy but care should be taken to not have too much large deep sea fish (e.g. Tuna, flake) due to the mercury and lead content which can be accumulated. And finally, foods more likely to be contaminated with Listeria bacteria (e.g. Soft cheeses, pate, deli meats, soft serve ice-cream) should also be avoided.

In summary, a balanced diet is important in pregnancy and look at making healthy food choices. The only supplements that are necessary are folate and iodine, as well as iron and calcium if you are found to be deficient in the third trimester. And if you have a sweet tooth like myself, it’s ok to have dessert every now and again but maybe just not everyday!


– Dr. Sze Wey Lee
Obstetrician & Gynaecologist


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