For a large percentage of women, the time when they gain the most weight is when they are pregnant. More than 25% of women gain more than 40 pounds during pregnancy. Typically, 18 to 20 pounds are due to the baby and pregnancy changes, so the rest of the weight gain (20+ pounds) will stay on your body after childbirth.

The Institute of Medicine now recommends the following guidelines for pregnancy weight gain, depending on body type, with the average being 30.5 pounds for women in the U.S:

Underweight Women 28-40 pounds
Normal Weight Women 25-35 pounds
Overweight Women 15-25 pounds
Obese Women 11-20 pounds

As you can see, it’s imperative to watch what you eat. Here are some tips we think you will find beneficial for eating right, not only to keep your weight within reason, but also to help with pregnancy challenges:

Cut down on eating out in restaurants and fast food restaurants. The expense is high as is the calorie, fat and salt content. The typical American household spends $2,668 a year in eating out.

Make sandwich, soups and salads at home. Learn how to cook some simple dishes. Over the next five years you will save thousands of dollars and avoid a large amount of weight gain for you and your child.

Use low calorie salad dressings.

Avoid fried foods. The high amount of fat not only adds to weight gain, but fat slows the emptying of the stomach and therefore worsens gastric reflux that causes heart burn.

Drink low fat milk-- 2% or preferably 1%. Actually, 2% milk is 37% calories from fat and 1% is 18% calories from fat. One of many examples of deceptive food labeling.

Avoid nuts, they are high in calories and fat. A handful of peanuts (3.5 ounces) contains over 600 calories and a day’s fat requirement for a woman.

Get vitamins from food sources as well as a supplement.

If you are underweight, a study suggests you might consider taking a vitamin supplement that contains 25 mgm of zinc, which tends to increase the weight of babies.

Avoid fish that is high in mercury. The danger is that methyl mercury can affect the central nervous system in the fetus. Fishes that are high in mercury are swordfish, shark, king mackerel and tile fish.

For constipation, increase the fiber in your diet. Fiber One cereal has the highest fiber. Also drink plenty of water and exercise.

For nausea, eat carbohydrate rich foods that are easy to digest such as crackers, cereal, pretzels or rice cakes. Fatty foods delay stomach emptying and will worsen nausea and vomiting. Cold foods are also tolerated better than hot foods.

Remember iron pills can cause nausea and constipation.

Eat slowly so the hormones released from your intestine have time to signal your brain that you are getting full.

Don’t make the mistake of classifying carrot cake as a vegetable.

When you go to the buffet don’t get a huge amount of food so you have to eat it with a knife and a forklift.

You can see how easy it can be to eat right once you have the right tips. Pregnancy is not the time to let yourself go, but rather the time to really watch your health. For additional tips on having a healthy pregnancy, look for great books on the topic such as Fetus to Fifth Grade.

Author's Bio: 

Want to get more pregnancy tips? Get Fetus to Fifth Grade The author, Dr. Schapira is an internationally recognized physician and researcher in the areas of nutrition and cancer prevention, and has been featured in the New York Times, Los Angeles Times, USA Today, CNN, NBC Nightly News and The Today Show. Stop by the site for a copy of the first three chapters.