Pregnancy: What to gain for healthy growth

Pregnancy can be a special and unique time for mothers-to-be. But with your body undergoing so many changes, it’s not uncommon to feel concerned about weight gain. While it’s worth remembering that some weight gain is completely normal and healthy (you are growing a small human after all!), gaining the right amount is particularly important.

Why is Healthy Weight Gain Important?

Many experts now agree that the first 1000 days of a child’s life may be one of the most critical periods for optimal growth and development. What’s important to appreciate is that these first 1000 days start very early on – right after conception. So it makes sense that what you eat, drink and do, both before and throughout those first 9 months, can have a direct impact on the long term health of both you and your baby. For example, excessive weight gain during pregnancy has the potential to increase the risk of short and long term health complications. This includes:

  • Pre-eclampsia (increased blood pressure in pregnancy)
  • Gestational Diabetes (diabetes during pregnancy)
  • A child with an increased risk of high blood pressure, obesity and associated health conditions later in life.

What is not discussed as frequently, is that food restriction and gaining too little weight during pregnancy may also cause harm and complications such as premature birth. So it’s vital to get this balance right by ensuring you are gaining weight within an optimal range, at the right stage of your pregnancy. 

What’s My Optimal Weight Gain Range?

Gaining weight within your optimal range is associated with an improvement in health outcomes for both mum and baby. The amount of weight you should be aiming for however, will depend on what you may have weighed before pregnancy. The below table can help to give you an idea in regards to how much weight you should be aiming to gain over the full term of your pregnancy, taking into account your body mass index (BMI) which considers your weight for height. 


  UNDERWEIGHT (<18.5)     12.5-18  
  HEALTHY WEIGHT (18.5-24.9)     11.5-16  
  OVERWEIGHT (25.0-29.9)     7-11.5  
  OBESE (>30.0)     5.9  

(Ministry of Health Guidelines: Guidance for Healthy Weight Gain in Pregnancy. 2014. Wellington, New Zealand.)

If you know your weight and height, you can calculate your BMI by dividing your weight (kg) by your height (in m); squared. Alternatively, next time you are in for a check-up with your health care professional, you can ask them to calculate it for you.  

BMI=  (Weight (kg))/(Height (m)^2 )

A healthy diet is an essential component in helping to ensure optimal weight gain, and a healthy pregnancy and birth outcome. Weight gain during pregnancy is also strongly related to foetal growth and therefore energy intake has a significant role to play. 

The Role of Energy in Healthy Weight Gain

While your energy requirements will still increase moderately, the days when pregnant women were able to consider themselves as “eating for two” are long gone – we now have a much better understanding of energy requirements to support pregnancy. Although you shouldn’t need to eat any more than what you normally do during the first 12 weeks, women are advised to increase their food intake by around 20-25% during the second and third trimesters of pregnancy. This is to help support the growth of the foetus and the expansion of maternal tissue (such as blood volume, extracellular fluid, mammary glands and maternal fat stores). For a women with an average energy intake of around 8000-8700kJ (1900 – 2100kcal). This is equivalent to a handful (½ a cup) of almonds and a glass of milk, or a wholegrain peanut butter sandwich and a banana.

Although additional energy needs increase only moderately, the requirements for micronutrients such as folate, iron and zinc are much higher during pregnancy. So aiming to eat nutrient dense foods (those with a high level of essential nutrients relative to energy), especially as the pregnancy progresses, will help to ensure an optimal nutrient supply without exceeding your energy intake. While certain foods need to be avoided during pregnancy, there is a range of nutrient dense foods available that will not only help to reduce the likelihood of excessive weight gain, but ensure you are loading up on essential nutrients. Nutrient dense foods that can be safely eaten include: freshly washed colourful fruit and vegetables, milk and yoghurt, legumes, nuts and seeds, wholegrain breads and cereals, and freshly cooked lean meats and oily fish.

Tips for Healthy Weight Gain during Pregnancy

While the thought of gestational weight gain can be daunting, remember that it is a very normal and healthy part of pregnancy! Here are a few tips to ensure you are gaining the right amount of weight, at the right time.

Nourish Yourself.

Although there is no need to increase your food intake in the first 12 weeks of pregnancy, you can use this time to consider what you are eating, and make sure you are getting a nutrient packed punch at every meal. Once you reach your second and third trimester, make sure the additional foods you are eating are still nutritious. Whether you’re adding in a few extra vegetables at dinner, swapping your fruit juice for milk, or opting for fruit and yoghurt when you feel like a sweet treat, it’s the small, consistent changes that are more likely to stick and help you on your way. 

Take Time Out to Exercise.

Regular exercise can also be of benefit to you and your baby. Provided you have the OK from your healthcare provider, you should be aiming for 30 minutes of exercise each day. If it’s been a while since you’ve exercised, it’s a good idea to start with a smaller goal in mind. You could begin with as little as 5 or 10 minutes each day, and work towards the full half hour. This could be as simple as going for a walk at lunch time, talking the stairs over the lift, or parking a little bit further away from the supermarket. During this time, it’s also a good idea take care of yourself and avoid activities that may cause any trauma to your abdomen. This includes contact sports such as soccer and netball, diving, skiing and kickboxing.

Keep Yourself in Check.

While you may be checking in with the doctor every so often, make sure you are regularly keeping track of your weight and what you are eating. Take ownership and try keeping yourself accountable. Remember that you are growing a small baby – they will be exposed to whatever you may eat or drink and it’s those nutrient dense foods that will be of most benefit to them! 

Get Informed

Keep yourself well informed – understand what’s happening at each stage of your pregnancy, listen to your body, and don’t be afraid to ask your doctor or midwife any questions. There are a number of other reputable websites that will be able to provide you with more information on what to expect throughout the course of pregnancy. 



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