You gained 30 lbs. during pregnancy but your baby only weighed eight of those. But, you don’t feel like you gained all that weight in body fat, so you might be wondering where the rest of that scale jump came from. There are a lot of reasons women gain weight during pregnancy and a lot of different places they gain it. For the most part, those scale increases indicate that your body’s doing its part to prepare you and your baby for a healthy gestation and delivery.

Average Gain

The average healthy weight gain during pregnancy depends on how much you weighed before you go pregnant. Women at a healthy weight should gain an average of 25 to 47 lbs., according to the American Pregnancy Association. Women who were underweight before conception should gain an average of three more pounds than women at a healthy weight. Overweight women should still aim to gain weight during pregnancy, but should limit it to 15 to 25 lbs., unless directed to lose weight under the supervision of a doctor to minimize pregnancy complication risks.

It’s Not All Baby

Only about 6 to 8 lbs. of your pregnancy weight gain is the baby itself. The rest comes from changes to your body that support your pregnancy. For example, you’re likely to gain 7 lbs. or more of fat, which your body uses to prepare for breastfeeding and to store nutrients. Your breasts may increase by as much as 2 lbs. and you gain 6 lbs. from your enlarged uterus, placenta and amniotic fluid. The rest of your weight gain comes from increased blood and body fluid.

Over and Underweight Moms-to-Be

Being underweight or overweight during pregnancy doesn’t necessarily mean you’ll have complications, as long as you care for yourself. Underweight women can safely increase the calories they eat from healthy foods, like fruits, vegetables and whole grains, to increase their body weight. The topic of weight loss during pregnancy is controversial, but the American Congress of Obstetricians and Gynecologists recommends women limit weight gain during pregnancy, which often translates to fat loss since body volume increases, even as the scale stays the same. Obesity increases the risk of certain complications, namely gestational diabetes and cesarean delivery, so your doctor will help you determine if the benefits of weight loss outweigh any potential risks.

Carrying Multiples

Two babies doesn’t mean double the weight gain, although it may feel like it. Moms carrying twins gain an average of 35 to 45 lbs. during pregnancy. Women carrying more than two babies will gain different amounts of weight depending on how many babies they’re carrying and how long their pregnancies are able to progress before delivery becomes imminent. Multiples are often born early via cesarean section to reduce the strain on the mother’s body.

Tips for Controlling Weight Gain

The baby and related fluid and tissue are something you don’t need or want to try to control during pregnancy. What you can control is how much fat you gain. Pregnancy can be a time of cravings and emotional turmoil, which often leads to overeating. A better strategy for controlling weight gain is to eat whenever you’re legitimately hungry and stop eating when you feel full, but not stuffed. Skip fast-food windows and focus instead of lean meats low in saturated fat, high fiber fruits and vegetables, nutrient-rich whole gains and low-fat dairy. Save high-calorie snacks, such as ice cream and pizza, for special occasions.