While pregnancy is not the time to lose weight, women should not use their expanding bellies as an excuse to eat more than is necessary. The amount of food a woman needs during pregnancy depends on a number of things including your body mass index (BMI) before pregnancy, the rate at which you gain weight, age and appetite. All pregnant women should eat a variety of nutrient-rich foods each day. You may also need to take a vitamin and mineral supplement if recommended by your physician. (See Eating Right During Pregnancy.)
Many women start off pregnancy overweight or obese; many gain more weight than is healthy during their pregnancy. Research shows the risk of problems during pregnancy and delivery is lowest when weight gain is kept within a healthy range. Obesity during pregnancy is risky for both mother and child. Some risks include gestational diabetes, gestational hypertension (high blood pressure), Cesarean delivery, birth defects and even fetal death. If a women is obese during pregnancy, it also raises the chance her child will be obese later in life.
Weight Gain Guidelines
The latest weight gain guidelines by the Institute of Medicine are based on a women's BMI before pregnancy. (See Understanding Body Mass Index (BMI).) The amount of weight you should gain depends on what category your pre-pregnancy BMI lands in:
- Underweight: BMI below 18.5
- Normal weight: 18.5 to 24.9
- Overweight: 25.0 to 29.9
- Obese: 30.0 and above.
The weight ranges below are for a full-term pregnancy:
- Underweight: 28 to 40 pounds
- Normal: 25 to 35 pounds
- Overweight: 15 to 25 pounds
- Obese: 11 to 20 pounds.
For twins, the recommendations naturally go up:
- Normal: 37 to 54 pounds
- Overweight: 31 to 50 pounds
- Obese: 25 to 42 pounds.
There are no set guidelines for underweight BMI weight gain with twins.
In general, pregnant women need between 2,200 calories and 2,900 calories a day. A gradual increase of calories as the baby grows is the best bet. Here is an overview of how calorie needs change during each trimester:
- The first trimester does not require any extra calories.
- During the second trimester an additional 340 calories a day are recommended.
- For the third trimester the recommendation is 450 calories more a day than when you are not pregnant
Avoid extra calories by cutting down on foods high in fat and added sugars. Replace regular soda, sweets and fried foods with healthy options like low-fat milk and yogurt, whole fruit and whole grains.
Physical activity can help manage weight gain. The activity guidelines for pregnant women are 30 minutes of moderate exercise on most, if not all, days of the week. Make sure to talk with your doctor before starting or continuing any exercise routine.
Reviewed January 2013