How Many Calories Should I Eat During Pregnancy? A Trimester Guide to Calorie Tracking

For a single pregnancy, most people need no extra calories in the first trimester, about 340 extra a day in the second and about 450 extra a day in the third. If you needed 2,000 calories before pregnancy, that is roughly 2,000, 2,340 and 2,450 a day. Twins, your starting BMI and your activity level change the number, so confirm it with your provider.

Search "how many calories should I eat during pregnancy" and you will hear that you are "eating for two". That is not how it works. A baby needs far less energy than an adult, and for the first three months most people need no extra food at all.

This guide gives you the trimester numbers health authorities use, the weight gain that goes with them, and a safe way to use a calorie tracker while you are pregnant. It is general information. Your obstetrician, midwife or a registered dietitian should set your personal targets.

How many extra calories do you need in each trimester?

The figures below come from the National Academies' energy requirements for pregnancy, which the American College of Obstetricians and Gynecologists (ACOG) also uses. They assume one baby and a healthy pre-pregnancy weight.

Trimester	Weeks	Extra calories per day	If you needed 2,000 kcal before
First	1–13	About 0	About 2,000 kcal
Second	14–27	About 340	About 2,340 kcal
Third	28–40	About 450	About 2,450 kcal

Three hundred and forty calories is not much food. It is about a Greek yogurt with fruit and a handful of nuts, or a turkey sandwich on whole-grain bread. Four hundred and fifty is a sandwich and a glass of milk.

The numbers change if you:

• Are carrying twins or more. Needs are higher, and your provider will give you a separate target.
• Started pregnancy underweight or with a high BMI. Your weight-gain range changes, so your calorie target does too.
• Have a physical job or train hard. Your baseline was already higher than average.

To find your starting number, work out your pre-pregnancy maintenance calories with a TDEE calculator, using your pre-pregnancy weight, then add the trimester amount. Treat the result as an estimate to check with your provider.

How much weight should you gain during pregnancy?

Calories in pregnancy exist to support healthy weight gain, so the two numbers go together. These are the Institute of Medicine ranges for one baby, which the CDC and ACOG use:

Pre-pregnancy BMI	Total weight gain
Underweight (below 18.5)	28–40 lb (12.5–18 kg)
Healthy (18.5–24.9)	25–35 lb (11.5–16 kg)
Overweight (25–29.9)	15–25 lb (7–11.5 kg)
Obesity (30 or higher)	11–20 lb (5–9 kg)

Most of the gain happens after the first trimester. Early on, a gain of 1 to 4.5 lb is typical. After that, many people gain around a pound a week in the second and third trimesters if they started at a healthy BMI.

Weekly weight bounces around with water and digestion, as it does outside pregnancy (see why your weight fluctuates). Look at the trend over a few weeks, and let your provider judge whether you are on track at your appointments.

Should you track calories while pregnant?

Tracking is not required, and many people never do it. It can help if:

• Nausea or food aversions make you unsure whether you are eating enough.
• You have gestational diabetes and your care team wants you to watch carbohydrates.
• Your provider says your weight gain is well above or below your range.
• You simply want to check that protein and regular meals are covered.

It is a poor fit if counting numbers makes you anxious, or if you have a history of disordered eating. In that case, tell your provider, and ask for a dietitian referral instead of logging food.

What to focus on instead of the calorie number

During pregnancy, what you eat matters at least as much as how much. When you log meals, check these as well:

• Protein. The recommended intake in pregnancy is about 71 g a day, up from 46 g. Eggs, dairy, poultry, fish, beans and tofu make this easy. Our guide to how much protein you need per day explains the basics.
• Folate, iron, iodine and choline. Most of this comes from a prenatal vitamin, but leafy greens, beans, lean red meat, eggs and dairy help.
• Omega-3s. The US Dietary Guidelines suggest 8 to 12 oz a week of low-mercury seafood such as salmon, sardines or shrimp.
• Regular meals. Long gaps without food make nausea and heartburn worse for many people.

Is a calorie deficit safe during pregnancy?

On your own, no. Guidance for pregnancy is to aim for healthy weight gain, not weight loss. Searches for "calorie deficit while pregnant" usually come from people who started pregnancy with a higher BMI and want to avoid gaining too much. That is a real concern, and the answer is a lower gain range (11 to 20 lb for a BMI of 30 or higher) that your provider monitors, not a diet you run yourself.

If you used a calorie app to lose weight before you got pregnant, change your settings now. Most trackers keep a weight-loss deficit running until you turn it off.

Common calorie tracker problems during pregnancy (and fixes)

General calorie apps are built for weight loss. That causes a few predictable problems when you are pregnant.

1. The app still has a weight-loss goal. Switch to maintain weight, or replace the target with the one your provider gave you.
2. The target never goes up. Apps do not know your trimester. Raise the target yourself at about week 14 and again at about week 28.
3. Red warnings when you go "over". If the app treats your extra 340 calories as a failure, ignore the color. Your provider's number is the one that counts.
4. Weight gain looks like "lack of progress". It is the goal. Some people prefer to stop logging weight in the app and leave that to their appointments.

How to use SlimAI if you are pregnant

SlimAI is a general calorie and macro tracker, not a pregnancy app. It does not build pregnancy-specific targets, and it is not a substitute for prenatal care. If you want to log food while pregnant, here is how to set it up:

• Pick "Maintain weight" as your goal, not "Lose weight".
• Enter your provider's numbers. SlimAI Pro lets you set your own daily calorie, protein, carb and fat targets, so you can type in what your care team recommends and update it each trimester.
• Log quickly. Snap a photo, say what you ate, or type it. The AI estimates calories and macros, and you can edit ingredients and serving sizes before saving. Read how accurate AI calorie tracking is to know where photo estimates need a quick check.
• Track water. The water tracker helps if you are prone to forgetting to drink.

Conclusion

For a single pregnancy, most people need no extra calories in the first trimester, about 340 more a day in the second and about 450 more in the third. Those calories support a weight gain range set by your starting BMI. A calorie tracker can help you check you are eating enough and getting enough protein, as long as you turn off weight-loss goals and use the targets your provider gives you.

Sources and References

• Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. National Academies Press, 2005.
• Institute of Medicine and National Research Council. Weight Gain During Pregnancy: Reexamining the Guidelines. National Academies Press, 2009.
• American College of Obstetricians and Gynecologists. Nutrition During Pregnancy (FAQ).
• Centers for Disease Control and Prevention. Weight Gain During Pregnancy.
• U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020–2025, Chapter 5: Women Who Are Pregnant or Lactating.

This article is for general information and is not medical advice. Always follow the guidance of your obstetric care team.