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8 min read

BY LAUREN BRENTON | Endorsed  Midwife & Childbirth Educator 

Have you heard the term “eat for two” when talking about weight gain in pregnancy? Unlike previously thought,it is recommended to not eat for two. It is however, recommended to focus on increasing your nutrient intake during pregnancy rather than eating for two. During pregnancy, it is normal for women to gain weight however this remains quite a large stress for many women and gaining too much weight can lead to adverse outcomes for the mum or baby.

In this Q&A we will explore how much weight gain is normal for pregnancy, why you gain weight and what contributing factors come in to play with weight gain. Remembering, that everyone and every pregnancy is different so comparing your weight gain to your friends or family is not recommended and can make you feel bad about yourself when you shouldn’t.

1. How much weight will I gain during pregnancy?

During pregnancy your weight is measured using your Body Mass Index (BMI) and this will be calculated based off your pre -pregnancy weight and your height.  How much weight is healthy for you to gain depends on your BMI that is calculated at your first antenatal appointment. The below table is a helpful guide on how much weight gain is a healthy during pregnancy.

BMI table for recommended pregnancy weight gain
Table 1: Healthy Weight Gain During Pregnancy Based on BMI (RANZCOG, 2022)


2. What is normal? How do I know if I am putting on too much or too little weight?

Eating a healthy well-balanced diet is essential in helping your baby to grow and develop. Eating nutritious food along with regular physical exercise can help contribute to a healthy pregnancy. According to Table 1, for a woman with a normal pre-pregnancy BMI of 18.5-24.9 it is recommended to gain between 11.5-16kg. So, let’s break that down more.

This means that for a healthy BMI, a woman generally will only gain 0.5-2kg in the first trimester due to morning sickness and pregnancy changes, and then gain an average of 0.42kg per week in the second and third trimesters. It is important to not gain too much weight, just as it is important to not gain too little weight. You should not diet or try to lose weight during pregnancy, as this can increase the risk of having a low birth weight baby.

Pregnancy weight gain and woman on scales

To make sure that you are gaining a healthy amount of weight during the pregnancy, you can weigh yourself regularly throughout. If you have any concerns during the pregnancy, discuss these with your healthcare provider. In addition, some healthcare providers may weigh you at each visit to help you stay on track and educate you if needed. It’s important to understand that healthcare providers are not weighing you to make you feel bad about your weight gain, but instead to help and support you to gain a healthy weight.

3. Do you have any tips for maintaining a healthy weight during pregnancy? 

Here are some tips that you can follow to develop a healthy weight gain during pregnancy:
  • During the first trimester, you don’t need to eat any more food than you would normally eat. Most women struggle to eat during the first trimester. If this is you, try to focus on eating small amounts of nutritious food throughout the day rather than large meals. You may also need to focus on eating when you feel okay during the day.
  • The equivalent amount of food required per day for someone with a healthy BMI is one peanut butter sandwich and a banana.
  • Try to avoid sweetened drinks, soft drinks, or fruit juices.
  • Try to swap out white grains for wholemeal grains and breads.
  • Try to have at least 2x servings of fruit and 4x servings of vegetables a day along with your protein.
  • Look for healthy snacks such as yoghurt, cheese, cereal, or wholemeal sandwiches.

4. Why do I gain weight during pregnancy? What are the contributing factors that are out of my control?

Weight gain during pregnancy is normal due to the growth of the baby, the amniotic fluid around baby and the growth of the placenta. By the 3rd trimester of pregnancy, your body has increased its total blood volume by 40-50% to support your growing baby.

Baby weight gain - mother looking at sonogram

In addition, your body is more likely to retain fluid due to the hormonal and physical changes of pregnancy. These physiological changes are essential for your body to support your growing baby and will increase your weight gain beyond your control. Aside from these physiological changes, genetics also come into play and can impact the amount of weight you gain.

Furthermore, conditions such as Hyperemesis Gravidarum (HG) may impact the amount of weight you gain and leave women at risk of early pregnancy loss as well as insufficient weight gain in the pregnancy (Meinich & Trovik, 2020). HG is a debilitating condition with extreme nausea and vomiting that can impact all areas of women’s lives. If you are experiencing HG, it is essential that you work together with your healthcare team to try minimising your symptoms and increase your nutrient intake.

5. What are the problems with not gaining enough weight during pregnancy?

Women who don’t gain enough weight during pregnancy can increase the risk of having a baby who:
  • Is born prematurely
  • Is born with a low birth weight
  • Has nutritional problems 

6. What are the problems with gaining too much weight during pregnancy?

Increased weight gain during pregnancy may increase the risk of you experiencing one of these complications:
  • A blood clot in the leg or lungs
  • Gestational diabetes
  • High blood pressure or pre-eclampsia
  • Difficult to monitor your baby during pregnancy and/or labour using a doppler or GTC or ultrasound. It may also make an epidural during labour more difficult to insert.
  • Your baby born weighing over 4kg
  • Increased risk of stillbirth
  • Increased chance of the baby becoming obese and developing diabetes later in life

7. What problems might I still expect even with a healthy weight gain?

Even maintaining a healthy weight, the extra weight gained from carrying your baby during pregnancy may be associated with:
  • lower back pain
  • hip & pelvic girdle pain
  • sciatica pain
  • Swollen feet and fluid retention.

8. What are your tips for managing some for managing these discomforts?

TheRY pregnancy belly band support

  • Lower back pain: Daily exercise, maintaining good posture, seeing a women’s health physiotherapist and using supportive clothing such as slimline pregnancy belt can help to take the strain off the ligaments of your lower back. Therefore, reducing your discomfort.
  • Hip & Pelvic girdle pain: As with lower back pain, hip and pelvic girdle pain are caused by the hormones of pregnancy which loosen the ligaments in the pelvis to help baby wiggle down. This can cause discomfort, which can sometimes be severe. Gentle daily exercise, trying not to sit or stand for prolonged periods of time, avoid deep squats, roll over slowly in bed, try gentle stretches or yoga, ice every 20-30 mins for 2-3 hours and seek help from a women’s health physiotherapist.
  • Sciatica Pain is often caused by pressure on the sciatic nerve which causes pain. To help manage sciatica pain it is important to stay hydrated, and do gentle exercises such as pregnancy yoga and stretching. Pregnancy belly bands can help support and redistribute the weight of your growing belly to alleviate discomfort and help with managing hip, sacroiliac and pelvic pain. A slimline pregnancy belt as this will be more comfortable and less bulky.
  • Fluid retention: Swelling during pregnancy is common, due to the increased fluid retention from pregnancy hormones. As with any injury, to reduce swelling it is important to follow the RICE acronym – Rest, Ice, Compression, Elevate. This is where TheRY graduated compression socks and tights will become your best friend, helping to reduce swelling and associated discomforts.
TheRY graduated compression socks to ease pregnancy swelling



Understanding that it is completely normal and necessary to gain weight during pregnancy is essential in helping you feel confident in your changing body. Knowing how much weight is normal and how to manage associated issues you can ensure a healthier and more comfortable pregnancy. If you have any concerns about your weight gain or associated discomforts it is important to seek individualised advice from your maternity care provider and a women’s health physiotherapist.


Meinich, T., & Trovik, J. (2020). Early maternal weight gain as a risk factor for SGA in
pregnancies with hyperemesis gravidarum: a 15-year hospital cohort study. BMC pregnancy and childbirth20(1), 255.
Ministry of Health. 2014.
Guidance for Healthy Weight Gain in Pregnancy. Wellington: Ministry of Health.
NSW Health. (2022).
Hyperemesis Gravidarum. Sydney, NSW; NSW Health. Retrieved January 18, 2024.
RANZCOG. (2022). Why your weight matters during pregnancy. Melbourne, VIC; RANZCOG.
The Royal Women’s Hospital. (2019). Pregnancy-Related Pelvic Girdle Pain. Melbourne, VIC; The Royal Women’s Hospital.
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