What to Eat When You're Pregnant: Second Trimester

Congratulations! You made it to the second trimester of pregnancy. You can take a deep breath and relax. The risk of miscarriage has dropped dramatically, and you are hopefully coming out of the fog of exhaustion and morning sickness. Some women will continue to be sick throughout pregnancy, but the worst should be over. The second trimester is the best, according to veteran moms, because the extreme fatigue and sickness have faded but you are not yet feeling the (physical) weight of the baby.

What's Going on in Your Body

Your baby is now about the size of a lemon and its head is one-third of its body size. "In the second trimester of pregnancy, the baby is continuing in rapid growth and development," says Crystal Karges, M.S., R.D.N., a San Diego-based private-practice dietitian and lactation consultant. The baby's sex will become clear, toenails will form, and his or her eyes will begin to move-all in the second trimester.

Most women feel the best and most energized in the second trimester. If this sounds like you, get moving. Take advantage of the times you feel great to get in some exercise to help you gain weight healthfully. You should gain about 1 pound per week for the rest of the pregnancy if you were a healthy weight when you conceived (BMI 18.5-24.9). If your BMI was 25 or higher when you got pregnant, aim to gain about 1/2 pound per week during the second and third trimesters.

Although the nausea might be gone, other symptoms may arise in the second trimester. "Because your body is making room for the baby and your growing uterus is putting pressure on your stomach, you might start to experience some gastric reflux (heartburn)," says Ingrid Anderson, R.D.N., founder of Results Dietetics. "Ligaments that support a woman's expanding belly will also begin stretching, which can cause achiness known as round ligament pain. With increased weight gain and pregnancy hormones can come leg cramps as well as mild swelling of the lower extremities," says Karges. That's not all. Your ta-tas are growing too. "Sometimes moms-to-be may experience further increased breast tenderness (and growing breast size) and possibly start experiencing back aches from pregnancy-related weight gain," says Lindsey Janeiro, R.D.N., C.L.C., dietitian and owner of Nutrition to Fit.

Important Nutrients

Recipe to Try: 8-Layer Taco Salad

Iron: Found in meat, poultry, seafood, beans and dark leafy greens.

Calcium: Found in dairy (milk, yogurt, cheese) and dark leafy greens.

Omega-3 fatty acids: Found in fatty fish, chia seeds, flaxseeds and fortified foods.

Magnesium: Found in nuts and seeds, bananas and yogurt.

Vitamin D: Found in fortified foods, like milk, soymilk and fortified cereals; also in fatty fish and egg yolks.

Folic acid: Found in beans, fruits, leafy green vegetables and your prenatal vitamin.

Here's some good news for you: you can eat more now. You should increase your calories by an extra 340 per day in the second trimester to support your baby's growth and development. Don't live by "eating for two" though, or you could gain an unhealthy amount of weight, possibly leading to poor outcomes for you and your baby. Not to mention, the more you gain, the more you will have to lose post-delivery (no, thanks!). If your BMI is healthy at conception (18.5-24.9), you should gain 25-35 pounds throughout pregnancy, according to the Institute of Medicine. If your BMI is under 18.5, you should gain 28-40 pounds. If you are overweight (BMI 25-29.9), you should gain 15-25 pounds during pregnancy, and obese women (BMI 30 and above), should aim for 11-20 pounds of weight gain during pregnancy.

There is no need to count calories, though. Focus on food groups, not numbers. "Foods that are high in calories but won't have detrimental effects on your blood sugar and cholesterol include avocados, nuts (such as walnuts or almonds) and nut butters, seeds (such as pumpkin seeds or ground flaxseeds), unsweetened dried fruits and hummus," says Molly Cleary, R.D., a dietitian at New York-Presbyterian Hospital. Iron is also important, she says. "Try getting your iron from at least one serving of seafood or poultry, a half cup of beans, and at least one serving of leafy greens daily. Bonus points if you eat your plant-based iron with vitamin C, such as citrus foods or red bell peppers." Vitamin C increases the absorption of iron. "Calcium is also of particular concern," she says, "It can be found in dairy (such as yogurt and low-fat milk), other fortified milk substitutes and leafy greens."

Karges notes that vitamin D, magnesium and omega-3 fats are also crucial in the second trimester for the baby's skeletal and brain development. Continue taking your prenatal vitamins throughout the entire pregnancy.

Exercise during the Second Trimester

Before you get moving, get the OK from your doc. Once you are cleared, move your body in a way that feels good to you. "Keeping the body active and strong will give the mom-to-be more energy, a better night's rest, strength as the growth of the belly continues, as well as help with making smarter nutritional choices," says Tara Mazanec, a personal trainer and holistic health counselor in Boston.

Kayla Mehr, also a trainer in Boston who specializes in prenatal exercise, says, "I recommend a strength training program three to four days a week to help prepare for labor and for the strength she will need for carrying and lifting her baby. On the other days of the week, cardio and/or prenatal yoga is a great way to cross-train and help improve endurance, stretch tight muscles and focus on meditation."

"During the second and third trimesters, a pregnant woman should focus on building more strength in her back to help with the increase in weight on her front side," says Mehr. She also recommends women do seated rows to help with the change in posture, as well as squats and pelvic-floor exercises (yes, we're talking kegels).

Only a few movements are a no-no in the second trimester. "Avoid extremely high-intensity/high-impact exercise where the breath is labored for an extended period of time, avoid lying flat on your back, and listen to your body if you feel you need to rest during your workout," says Mazanec. Of course, always get the go-ahead from your doctor before trying a new exercise routine.

Watch: How to Make a Healthy Taco Salad Recipe

• What to Eat and Avoid during Pregnancy: What to Eat and Avoid during Pregnancy
• Healthy Pregnancy Meal Plan: Healthy Pregnancy Meal Plan