Most pregnant women need about 1,800 calories per day in the first trimester, 2,200 in the second, and 2,400 in the third. That said, your actual number depends on your pre-pregnancy weight, how active you are, and whether you’re carrying more than one baby. The old advice of “eating for two” overstates it considerably. In reality, pregnancy adds roughly 300 extra calories per day on average, which is about the size of a peanut butter sandwich on whole wheat.
Calorie Targets by Trimester
Your body’s energy demands don’t jump the moment you get a positive test. In the first trimester, calorie needs are essentially the same as before pregnancy. The baby is tiny, and most of the early work is building the placenta and expanding your blood volume, not fueling rapid fetal growth.
The real increase kicks in during the second trimester, when you need roughly 340 extra calories per day compared to your pre-pregnancy intake. By the third trimester, that rises to about 450 extra calories per day. For a woman who normally eats around 2,000 calories, the trimester targets look like this:
- First trimester: about 1,800 to 2,000 calories
- Second trimester: about 2,200 to 2,340 calories
- Third trimester: about 2,400 to 2,450 calories
These are general ranges for women at a normal pre-pregnancy weight. If you were underweight before conceiving, you’ll likely need more. If you started pregnancy at a higher weight, your provider may suggest staying closer to the lower end. The underlying principle from ACOG is roughly 35 calories per kilogram of your ideal body weight, plus 300 calories for the pregnancy itself.
Why Your Pre-Pregnancy Weight Matters
Calorie needs and weight gain targets are tied directly to your BMI before pregnancy. The CDC publishes weight gain ranges based on four BMI categories for women carrying a single baby:
- Underweight (BMI under 18.5): 28 to 40 pounds total gain
- 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
A woman aiming for the lower end of that weight gain range will naturally need fewer calories than one targeting the higher end. If you’re tracking closely, the weight gain itself is a better real-time signal than calorie counting alone. Gaining too fast in the second trimester often means calorie intake has crept higher than needed, while stalling weight gain can signal undereating.
What Your Body Is Actually Doing With Those Calories
Pregnancy raises your basal metabolic rate, the energy your body burns just to keep functioning, by 8% to 35% depending on the stage. The increase is modest early on and becomes more intense after the second trimester, when the baby is growing fastest and your body is maintaining a larger blood volume, a full placenta, and additional tissue.
This is why the calorie increase is backloaded into the later months. Your body simply isn’t burning much extra fuel in the first 12 weeks. By the third trimester, it’s supporting a baby that may gain half a pound per week, plus sustaining the infrastructure that keeps the pregnancy going.
Calorie Needs for Twins
Carrying twins changes the math significantly. Estimates vary, but most guidelines suggest women with a normal pre-pregnancy BMI need 3,000 to 3,500 calories per day when pregnant with twins. Underweight women may need as much as 4,000 calories, while women who started at a higher weight typically need 2,700 to 3,250.
Weight gain targets are also higher. The CDC recommends 37 to 54 pounds for normal-weight women carrying twins, compared to 25 to 35 for a single baby. Some research suggests that after 20 weeks, twin pregnancies require roughly 1,000 additional calories per day compared to a non-pregnant baseline. That’s a meaningful amount of food, and many women carrying multiples find they need to eat frequently throughout the day to hit those targets comfortably.
What 300 Extra Calories Actually Looks Like
Three hundred calories is less food than most people imagine. Any of these snacks gets you there:
- Apple slices with 2 tablespoons of peanut butter: about 304 calories
- A banana smoothie made with a cup of frozen strawberries and 3/4 cup yogurt: about 297 calories
- Two slices of whole wheat toast with a hard-boiled egg and a glass of orange juice: about 319 calories
- A bowl of oatmeal made with milk, topped with mixed berries, plus a glass of apple juice: about 331 calories
- A whole wheat tortilla with half a cup of hummus and some snap peas: about 307 calories
- Whole grain cereal with skim milk and a sliced banana: about 318 calories
The theme across all of these is nutrient density. Three hundred calories of cheese crackers technically meets the number, but a snack that combines protein, fiber, and vitamins does double duty by covering the extra micronutrient demands of pregnancy at the same time.
Adjusting for Activity Level
If you were active before pregnancy and continue exercising, you’ll burn more calories than the baseline estimates assume. The standard trimester targets are built around moderate activity levels. A woman who runs, swims, or does strength training several times a week will need to eat more to compensate, just as she would outside of pregnancy.
There’s no single formula for this, but paying attention to hunger cues and weight gain trends is the most practical approach. If your weight gain is tracking within the recommended range and you feel adequately fueled during workouts, your intake is likely on target. Persistent fatigue, dizziness, or weight gain that stalls for several weeks can indicate you’re not eating enough to support both exercise and pregnancy.
Risks of Eating Too Little
Undereating during pregnancy carries real consequences. Restricting calories limits the baby’s ability to reach its full growth potential, even in women who started pregnancy at a higher weight. Research on calorie restriction in obese pregnant women found that it reduced birthweight without improving pregnancy complications, meaning the restriction caused harm without offering the benefits it was intended to produce.
Your body also needs to build energy stores during pregnancy that it draws on later for fetal growth and, eventually, breastfeeding. When calorie intake is too low to establish those stores, the developing baby may not get the sustained energy supply it needs during the rapid growth phase of the third trimester. Severely unbalanced diets in late pregnancy, particularly those very low in carbohydrates, have been linked to higher blood pressure in the offspring later in life.
None of this means you should eat without limits. Gaining significantly more than recommended is associated with its own set of problems, including gestational diabetes and complications during delivery. The goal is steady, appropriate weight gain that matches your BMI category, fueled by nutrient-dense food rather than empty calories.