Pregnancy weight: How much should you gain? Is it normal to lose weight?

How much should you gain? What’s too much and what’s too little? It’s a tricky topic, but here’s what you need to know.

We used to think that during pregnancy women should eat for two, but science has taught us that this wasn’t the right advice. A growing baby while still in the uterus doesn’t need a lot of kilojoules to grow as much as they need good nutrition.

Put simply, it’s not the amount of food a pregnant mother eats but what’s in it which makes a difference to her own as well as her baby’s health.

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Cropped high angle shot of a pregnant woman weighing herself on a scale

It’s hard to know what a healthy weight gain is. Source: iStock

RELATED: Pregnancy weight gain calculator

What we know to be true

Our idea of what a healthy weight looks like has changed over the last few years. Currently, almost 2/3 of Australians are overweight or obese, including women who are trying to conceive or who’ve started their pregnancy already overweight. Being overweight can affect normal ovulation and women who are overweight or obese are more likely to have problems conceiving.

Losing weight in pregnancy is difficult and generally not recommended. And losing pregnancy weight can also be challenging, especially if it’s more than the ideal amount. 

Studies have shown that around three out of four women don’t gain healthy amounts of weight during pregnancy. Roughly 25 percent don’t gain enough weight and almost 50 percent gain more than what is considered healthy.

Being overweight during pregnancy affects a mother’s mobility and her self esteem – increasing the risk of further weight gain.

Many of us, whether pregnant or not, eat for comfort and to soothe ourselves when we’re feeling sad, lonely, anxious or bored. It takes honesty and energy to learn how to develop other more healthy ways of meeting our needs.

RELATED: Could your pregnancy diet affect your baby’s health?

Young pregnant woman in a park eating an apple

You don’t need to obsess over food. Source: iStock

RELATED: Foods to avoid during pregnancy and why

What’s a healthy weight gain in pregnancy?

The amount of weight a mother should gain during pregnancy depends on her pre-pregnancy weight and how many babies she’s carrying. These two factors help to guide what is a healthy weight gain, which then reduces the risk of developing pregnancy complications.

If you were in a healthy weight range before conceiving, then an ideal weight gain is between 11.5-16 kgs during pregnancy.

Ideal weight gain (kgs) during pregnancy

First trimester 

1-1.5 kilograms

Second and third trimesters

1.5-2 kilograms each month until birth

Weight gain using BMI (body mass index)

Low BMI (under 18.5) before pregnancy

Between 12.5-18 kilograms 

Higher BMI before pregnancy (above 25)

Between 7-11.5 kilograms 

Check here for more information about weight gain if you have a BMI less than 25.

Check here for more information about weight gain if you have a BMI above 25. 

happy pregnant woman

Gaining too little weight is dangerous too. Source: iStock

Risks of not gaining enough weight during pregnancy

For women who are underweight before conceiving and who gain less than the recommended amount, there is an increased risk of premature birth and having an underweight baby. There is also a risk of having nutrient deficiencies, in particular iron and protein. 

Risks of gaining too much weight during pregnancy

Too much weight gain increases the risk of having a large baby and needing a caesarean section birth. This also affects healthy recovery time after birth and increases the risk of a range of pregnancy complications, both short and long term.

  • Gestational diabetes – especially if there’s been weight gained too rapidly in the first ½ of pregnancy.
  •  An increased risk of developing Type 2 diabetes in the future. 
  • Difficult birth and increased risk of having an assisted (forceps) birth. 
  • Pre-eclampsia.
  • Depression and anxiety.
  • Obesity and health issues for the baby as an adult.
  • Miscarriage and stillbirth.
  • Challenges with breastfeeding.

What can I do to not gain too much weight during my pregnancy?

  • Be mindful of what you’re eating, not too little or too much. Remember, it’s the nutrition in the food you’re eating which will support you and your baby to be healthy. 
  • Avoid ‘brown’ foods e.g. chips, fried food and processed foods. The colour of food is often a clue for how much it’s been processed. 
  • Aim for a colourful plate with lots of vegetables, protein and whole grains. 
  • Make healthy decisions about food and exercise. Staying within a healthy pregnancy weight gain is something which requires some thought and planning.
  • Don’t compare your pregnancy weight gain with other women. We are all individuals.

Exercise when you can. Around 30 minutes of physical activity on most days of the week is a healthy goal. Swimming, walking, bike riding, yoga and Pilates are all great options. 

10 top tips for healthy eating when pregnant

  1. Aim for 3 main meals and 2 snacks each day. Use hunger as a guide for when to eat. 
  2. Drink plenty of water and avoid drinking soft drink, juice and energy drinks which are all high in sugar.
  3. Eat plenty of vegetables, fruit, whole grains, lean meat, poultry, dairy foods and cereals. Check here for information on foods which carry a higher risk of containing Listeria. 
  4. Snack on nuts, (hard) cheese, crackers and vegetable sticks.
  5. Limit sweet treats like biscuits, cake, pastries and processed foods. These tend to be high in sugar and fat which lead to excess weight gain. 
  6. Eat mindfully. Try not to eat when watching television, in bed or looking at your phone.
  7. Get up and move when you can. Even short walks of 10-15 minutes can be helpful.
  8. Try to only buy healthy foods. It can really help to not have processed ‘treat’ foods in the house and to avoid temptation. Allow yourself the occasional treat though.
  9. Use cutlery when eating and be suspicious of foods which don’t require a knife and fork. Many fast foods can be eaten with one hand – this will give you a clue for what’s healthy or not.
  10. Ask your partner to support you. It’s easier to eat well when we feel we’re not alone. 


Speak with a dietician about what’s right for you. Some dieticians specialise in pregnancy-related health issues such as gestational diabetes. 

Chat with your maternity care provider. They can help you to monitor your weight gain at each antenatal appointment.

Jane Barry has qualifications in general, paediatric, immunisation, midwifery and child health nursing. She holds a Bachelor Degree in Applied Science (Nursing) and has almost 30 years specialist experience in child health nursing. She is a member of a number of professionally affiliated organisations including AHPRA, The Australasian Medical Writer’s Association, Health Writer Hub and Australian College of Children and Young People’s Nurses.