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Healthy weight, diet and physical activity pre-conception

The rates of women who are overweight or obese during pregnancy are increasing in Queensland. Carrying extra weight during pregnancy increases the risk of adverse health outcomes for both baby and mother. Weight reduction should be encouraged in the pre-conception period to reduce pregnancy complications. Even small amounts of weight loss can have health benefits.

Healthy weight for women planning pregnancy

Weight is commonly assessed using body mass index (BMI). Pre-pregnancy BMI is used as a guide for the amount of weight a woman should gain during pregnancy. This can be calculated by dividing weight (kg) by the square of the height (metres). The BMI categories for adults are:

  • Underweight – BMI of <18.5kg/m2
  • Healthy weight – BMI of 18.5 to 24.9 kg/m2
  • Overweight – BMI of 25 to 29.9 kg/m2
  • Obese – BMI of >29.9 kg/m2

These BMI ranges may not be appropriate for Aboriginal or Torres Strait Islander women, or some cultural populations. Higher or lower BMI ranges may need to be considered for these women (e.g. a BMI cut-off of 22 may be a more appropriate measure of a healthy weight BMI for Aboriginal and Torres Strait Islander women). Consider BMI with other measures and diet and lifestyle information, or refer to an appropriate health professional.

All health workers have a responsibility to display respect and support when discussing weight management. Providing appropriate information on diet and physical activity can assist in discussing healthy weight.

Healthy eating when planning pregnancy

Health workers should encourage and support women who are planning a pregnancy to enjoy a wide variety of foods from all five food groups to optimise their health and weight before pregnancy.

The Australian Dietary Guidelines recommend that women aim to consume the following on a daily basis:

  • 5 serves of vegetables or legumes/beans of different types and colours
    • 1 serve is equal to ½ cup cooked vegetables or legumes, 1 cup of salad, or ½ potato
  • 2 serves of fruit
    • 1 serve is equal to 1 medium or 2 small pieces of fruit
  • 6 serves of grain foods, mostly wholegrain or high fibre varieties
    • 1 serve is equal to 1 slice of bread, ½ cup cooked rice or pasta, or 2/3 cup of cereal
  • 2 ½ serves from lean meats, poultry, fish, eggs, tofu, nuts/seeds or legumes/beans
    • 1 serve is equal to 65-80g cooked meat or poultry, 100g fish, 2 eggs, or 1 small handful of nuts/seeds
  • 2 ½ serves of dairy foods, including milk, yoghurt, cheese or dairy alternatives (e.g. soy), mostly from reduced fat options
    • 1 serve is equal to 1 cup of milk, 1 tub of yoghurt, or 2 slices of cheese.
  • Drinking plenty of water is a good habit to start before pregnancy.

Other food and drinks are not needed as part of a healthy diet. Women should be encouraged to limit foods high in saturated fat, added salt and added sugars. Frequent consumption of these foods may cause weight gain, or prevent weight loss.

These recommendations are a general guide to assist women with healthy eating in the pre-conception period. Women needing assistance with diet or weight management should be referred to a dietitian.


Requirements for some nutrients are increased during pregnancy and food is unable to provide as much as is needed. Daily supplementation is often recommended for most women in preparation for pregnancy. Encourage women who are planning pregnancy to discuss this with their doctor or relevant healthcare professional.

Folic acid supplementation prevents risk of baby being born with a neural tube defect and is important in the early stages of pregnancy.

  • Inform women that supplementation of at least 400 micrograms per day from 12 weeks before conception and through the first 12 weeks of pregnancy reduces risk.
  • Encourage and support women to eat healthy foods containing folate alongside supplementation (e.g. green leafy vegetables, broccoli, oranges, avocado, or fortified breads and cereals).

Iodine requirements are increased during pregnancy and breastfeeding. Iodine is an essential vitamin for brain development and the nervous system.

  • Advise women who are planning pregnancy to begin taking an iodine supplement of 150 micrograms per day and continue to take supplementation during pregnancy and breastfeeding.
  • Encourage and support women to eat healthy foods containing iodine alongside supplementation (e.g. fortified bread, seafood, dairy foods). Advise when using table salt, always choose iodised table salt.
  • Encourage women with pre-existing thyroid conditions to seek advice from their doctor before taking an iodine supplement.

Physical activity when planning pregnancy

Physical activity has benefits for the health and wellbeing of all women. The Australian Physical Activity Guideline recommends that women planning pregnancy to undertake regular physical activity including:

  • Muscle strengthening activities at least 2 days per week, as well as
  • 2½ to 5 hours of moderate intensity physical activity each week, OR
  • 1¼ to 2½ hours of vigorous intensity physical activity each week, OR
  • An equivalent combination of moderate and vigorous intensity activity each week.

Women should be advised to talk to their doctor or appropriate health professional before beginning any new exercise activities or programs.

Alcohol, smoking and illicit drugs

Alcohol is not recommended for women planning pregnancy. Not drinking alcohol is the safest option (See: Australian Government’s alcohol guidelines).

Smoking and use of illicit drugs (e.g. illegal drugs or prescription drugs for another person) is not recommended for women planning pregnancy. It is best for parents, families and carers to avoid smoking and illicit drugs.

Encourage women to talk to their health professional for assistance with avoiding use of alcohol, smoking or illicit drugs.

More information

Queensland guidelines

National and international guidelines

Nutrient supplementation

Last updated: 13 May 2020

Resources for parents, families and carers

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