Eating for two? While it might sound like the golden ticket to overindulge in extra snacks and larger portions, don't let pregnancy give you the green light to exponentially increase your current food intake. Calorie needs during pregnancy don't differ much from pre-pregnancy needs, particularly during the first trimester (or first three months) of pregnancy when additional calories aren't needed.

During the second trimester of pregnancy, approximately 340 additional calories are needed per day. During the last trimester, that number increases to 450 calories per day. To put this in perspective, 300 calories can be added as a snack by enjoying an English muffin with 2 tablespoons peanut butter or a glass of reduced fat milk with a handful of almonds.

Weight gain recommendations for pregnancy are based on pre-pregnancy weight using body mass index (BMI). Your obstetrician or midwife will use BMI, along with other factors, to give you a healthful range for weight gain. The below ranges from the Centers for Disease Control and Prevention (CDC) will give you an idea of what your target weight gain might look like:

Single Pregnancy

Underweight (BMI <18.5): 28-40 pounds
Healthy (BMI 18.5-24.9): 25-35 pounds
Overweight (BMI 25-29.9): 15-25 pounds
Severely Overweight (BMI > 30): 11-20 pounds

Twin Pregnancy:

Underweight (BMI <18.5): 50-62 pounds
Healthy (BMI 18.5-24.9): 37-54 pounds
Overweight (BMI 25-29.9): 31-50 pounds
Severely Overweight (BMI > 30): 25-42 pounds

If unsure of your body mass index, use the Pregnancy Weight Gain Calculator from ChooseMyPlate.gov to calculate weight gain recommendations based on your height and pre-pregnancy weight.

Knowing your numbers is important because there are risks associated with gaining too little or too much weight. Less weight gain is associated with premature delivery and/or having a baby with low birthweight. Both of these conditions can increase baby's risk for illness and developmental delays.

Excess weight gain is associated with delivery complications and increased risk for cesarean. It may also lead to delivering a large baby, which increases the likelihood of obesity during childhood. Additionally, increased weight gain during pregnancy may be difficult to lose and thereby lead to you becoming overweight well after delivery. This increases risk for health concerns like high blood pressure, diabetes and cardiovascular disease.

To ensure you stay on track with weight gain recommendations, incorporate balanced meals and snacks throughout the day that include fruits, vegetables, lowfat dairy, whole grains and lean sources of protein. And talk to your healthcare provider about incorporating moderate physical activity, such as walking, swimming and yoga, into your daily routine most days of the week.