Weight during pregnancy

While it isn’t true that you need to ‘eat for two’ in pregnancy, you might feel hungrier at times or want to eat certain types of food. To stay healthy, it is important to pay attention to your body, keep active where possible, and eat foods that are good for you and your baby because being overweight or obese can increase the risk of problems in pregnancy. 

Your midwife can use your height and weight to estimate your body fat. This is called your body mass index, or BMI. Your midwife will work out your BMI with you at your first appointment in pregnancy. Your midwife or doctor might also ask to check your weight later in pregnancy


•    A BMI of 18.5–24.9 is considered healthy. 
•    For most people, a BMI between 25 and 30 is taken as overweight, and a BMI over 30 is taken as obese. 
•    For most people, a BMI of under 18.5 is considered underweight. 

If your BMI is under 20 when you first meet your midwife, they will discuss this with you. Being underweight can increase the risk of problems in pregnancy. 

If you have any concerns, ask for advice and help 

The advice for pregnancy is simple

  • You don’t need to eat for two. Even during the last few months of pregnancy a woman only needs an extra 200 calories a day (two slices of wholemeal toast or an apple and a banana, for example)
  • Try to do 150 minutes or more of moderate physical activity, such as walking, every week, right up until the baby is born. Build up to daily exercise if you’re not used to it. (If there are health reasons why you shouldn't exercise, talk to your midwife) 
  • If you're already overweight, you don’t need to put on more weight in pregnancy. 
  • Keeping active is a great way to keep fit, but if there are health reasons why you shouldn't exercise, or you are finding it hard to exercise for any reason, talk to your midwife
These short films on what to eat and keeping active were produced for Our Chance, a campaign by the charities Sands and Best Beginnings to raise awareness of health issues in pregnancy
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