It's a sentence anyone who is pregnant will hear: "Eat up, you're eating for two now." And while it's a tempting proposition (apart from during the morning sickness stage), it's not actually accurate information.
Gaining weight during pregnancy is completely normal -- healthy, in fact -- but it's important to eat the right types and amount of food to help both you and your baby during and after pregnancy.
How important is nutrition during pregnancy?
"When you're pregnant, the food you're eating is nourishing not just your own body -- it's nourishing your unborn baby," Chloe McLeod, accredited practising dietitian and sports dietitian, told HuffPost Australia.
"Making healthy food choices and eating the right foods to help with managing your own and your baby's health is absolutely imperative."
To ensure you're eating healthily, include lots of whole foods like vegetables, fruit, legumes, nuts, seeds and lean protein. And be mindful of three key nutrients: folate, calcium and iron.
"One of the main nutrients we need to be mindful of is folic acid, which is recommended to be taken in a supplement form, as a lot of people's diets are low in folate," McLeod said. "Not consuming enough folic acid has been shown to increase the chance of the baby having a condition called spina bifida.
"Other nutrients to be mindful of are iron and calcium. If the mother isn't getting enough of these (the nutrients will go to the baby first before the mother), for both the mother and the baby it can result in weakening of bones (for calcium), or low iron levels which can lead to fatigue and anaemia for the mother. Consuming enough of iron and calcium is incredibly important."
It's also important to consume enough energy in general when you're pregnant.
"A lot of mums really struggle with this from a morning sickness perspective as this stage can make it difficult to get enough food in," McLeod said.
"In that instance, I'd be saying to listen to your body and do what you can to manage the morning sickness -- plain foods, ginger, anti-nausea medications if needed, or see the GP if it's a real problem -- but don't put too much pressure yourself."
How much weight do you gain during pregnancy?
The recommended amount of weight gain during pregnancy depends on factors such as your weight/BMI prior to getting pregnant. To ensure proper nourishment of the baby, women who are underweight pre-pregnancy are advised to put on the most weight. On the other hand, women who are overweight or obese are advised to gain a much smaller amount.
"When you're looking at the weight gain, for someone who is within a normal, healthy weight range at the start of the pregnancy, you'll normally be expecting to gain around 11.5-16 kilos over the entire pregnancy," McLeod said.
"It does mean eating a little bit more, but it doesn't necessarily mean eating enough for two people. I like to suggest to listen to your body and listen to your appetite."
How much extra food should you eat when pregnant?
Despite what people tell you, when you're growing a human you don't exactly have to "eat for two".
"For someone within a normal, healthy weight range: during the first trimester there is no additional energy requirements," McLeod explained.
"During the second trimester it's about 1,400 kilojoules [340 calories] a day extra. In the third trimester it's around 1,900 kilojoules [460 calories] a day extra. So it's approximately an extra meal's worth per day -- a small-medium sized meal."
How much extra food should you eat when breastfeeding?
"Particularly when you're breastfeeding, your energy levels will increase quite considerably because of the extra energy that is required," McLeod said.
"For lactation, it's around an extra 2,000 kilojoules [480 calories] of food per day, which is quite a lot. It's often why people who are breastfeeding tend to lose a lot of the baby weight, as it ends up being a lot of food to consume for a lot of mums."
Snack ideas for pregnant and breastfeeding mums
Whether you're pregnant, breastfeeding or not, healthy snacks are going to be the same, McLeod explained.
"Enjoy things like nuts, fruit, veggie sticks with hummus, avocado or guacamole on crispbread, yoghurt or a smoothie (particularly when energy consumption needs to go up)," McLeod said.
For more nutrition information, here are foods to avoid while pregnant, and answers to commonly asked kids' nutrition and breastfeeding questions, as well as easy healthy eating tips.
If in doubt, always check in with your GP or healthcare professional.