Pregnancy Weight Gain: How Much, How Soon?
Unlike the equation used to calculate your BMI, the process of putting on pounds is not an exact science (if only it were that easy punch in the numbers, gain just the right number of pounds, at just the right rate!). Your rate of weight gain will depend on a variety of factors, such as your metabolism, your activity level, and genetics.
If you have a fast metabolism or you’re very physically active you may gain weight more slowly (and will consequently need to eat more calories) than someone who puts on weight by just looking at a pint of ice cream, or who leads a very sedentary lifestyle. That said, there are some general guidelines, and these, too, depend on your BMI. Here, some approximations:
If your BMI is less than 18.5, plan to gain 5 pounds in the first trimester and 28 to 40 pounds total during your pregnancy (roughly a pound a week).
If your BMI is between 18.5 and 25 (average weight), aim to put on about 3 pounds during the first trimester and plan to gain around 25 to 35 pounds total.
If you’re overweight (your BMI is between 26 and 29), gain 2 pounds during the first three months and between 15 and 25 pounds total before your baby is born (less than a pound a week).
If your BMI is 30 or more, you should gain around 11 to 20 pounds total and talk to your practitioner about managing your weight gain.