Most pregnant women need about 300 extra calories per day, but that number varies significantly depending on the trimester and your pre-pregnancy weight. In fact, during the first trimester, most women don’t need any extra calories at all. The increase happens gradually, ramping up as the baby grows and energy demands rise in the second and third trimesters.
Calorie Needs by Trimester
For women who start pregnancy at a normal weight, the general daily calorie targets break down like this:
- First trimester: about 1,800 calories per day (no increase needed)
- Second trimester: about 2,200 calories per day (roughly 340 extra)
- Third trimester: about 2,400 calories per day (roughly 450 extra)
The first trimester surprises a lot of people. The embryo is tiny, and the body’s energy demands haven’t meaningfully changed yet. Eating more than usual this early can lead to faster weight gain than recommended, which becomes harder to manage later. The real caloric ramp-up begins around week 13, when the placenta and baby are growing rapidly.
How Pre-Pregnancy Weight Changes the Numbers
The 300-calorie figure is an average, and your starting BMI shifts the target. Women who begin pregnancy at a higher weight need fewer additional calories because their bodies already carry larger energy reserves. The CDC recommends that women who start pregnancy with obesity need no extra calories in the first trimester, about 200 extra per day in the second trimester, and about 400 extra in the third.
These differences tie directly to weight gain goals. The recommended total weight gain during pregnancy varies by BMI category:
- Underweight (BMI under 18.5): 28 to 40 pounds
- Normal weight (BMI 18.5 to 24.9): 25 to 35 pounds
- Overweight (BMI 25 to 29.9): 15 to 25 pounds
- Obese (BMI 30 to 39.9): 11 to 20 pounds
Gaining more than the recommended range is associated with complications including gestational diabetes, higher rates of cesarean delivery, and larger-than-average babies that can make delivery more difficult. Gaining too little raises the risk of preterm birth and low birth weight. The calorie targets exist to keep weight gain within these ranges, not as rigid rules to hit each day.
Twin and Multiple Pregnancies
Carrying twins or more increases calorie needs substantially, though the exact number depends on your starting weight and activity level. As a rough guide, total daily calorie needs for a twin pregnancy range from about 3,000 calories for women who start at a higher BMI to about 4,000 calories for women who start underweight. That can mean 500 to 1,000 extra calories per day above your pre-pregnancy baseline.
Weight gain targets are also higher for twins. Normal-weight women carrying twins are advised to gain 37 to 54 pounds total, while overweight women should aim for 31 to 50 pounds and obese women for 25 to 42 pounds.
What Those Extra Calories Should Look Like
Three hundred calories is not a lot of food. It’s roughly a banana with two tablespoons of peanut butter, or a cup of Greek yogurt with some berries. The point isn’t to eat dramatically more but to eat slightly more of the right things.
Protein needs rise the most in the third trimester. Non-pregnant women typically need around 46 to 50 grams of protein per day, and pregnancy adds about 1 extra gram in the first trimester, 9 grams in the second, and 28 to 31 grams in the third. That third-trimester jump is significant, roughly equivalent to adding an extra chicken breast or a cup and a half of lentils to your daily intake. This protein supports rapid fetal growth, placental development, and increased blood volume.
Iron and folate deserve attention beyond calories. The WHO recommends 30 to 60 mg of supplemental iron and 400 micrograms of folic acid daily throughout pregnancy. Iron prevents anemia, which becomes more common as blood volume expands by nearly 50 percent. Folate is critical for preventing neural tube defects and ideally should be started before conception, since the neural tube closes within the first four weeks of pregnancy, often before many women know they’re pregnant.
Why “Eating for Two” Is Misleading
The old advice to eat for two dramatically overstates what’s needed. Doubling your calorie intake would mean consuming an extra 1,800 to 2,000 calories per day, roughly six times the actual recommendation for the second trimester. That level of overconsumption leads to excessive weight gain, which increases the risk of complications for both mother and baby and makes postpartum weight loss significantly harder.
A more accurate way to think about it: you’re eating for 1.15. The baby’s caloric needs are real but modest, and your body becomes more efficient at absorbing nutrients during pregnancy. Your intestines slow down, extracting more energy and micronutrients from the same amount of food. This is part of why first-trimester calorie needs barely change at all.
If you’re struggling with nausea in the first trimester and eating less than usual, that’s generally fine. Most women have enough nutritional reserves to support early fetal development even with reduced intake. The priority shifts in the second and third trimesters, when the baby’s growth accelerates and consistent, nutrient-dense eating matters most.