While there are certainly exceptions to any rule, in general, women shouldn't diet during pregnancy. There are several reasons for this. First, weight gain is an essential part of a healthy pregnancy for most women. Further, dieting can result in depriving your developing baby of the nutrients it needs to survive and thrive.
Weight Gain
During pregnancy, most women need to gain weight. If you were of a healthy body composition prior to becoming pregnant, your obstetrician will likely advise you to gain 25 to 35 pounds over the course of your pregnancy, explain Drs. Michael Roizen and Mehmet Oz in their book "You: Having A Baby." Women who are underweight prior to becoming pregnant may need to gain a bit more, while those who were overweight may need to gain less--or may not need to gain at all.
What the Weight Is
While it can be disconcerting for some women to watch the numbers on the scale increase dramatically during pregnancy, it's worth remembering that not all the weight you're gaining is fat. For a typical weight gain, you actually gain fewer than 7 pounds of body fat, explains the American Pregnancy Association. The remaining weight includes the baby, the placenta and amniotic fluid, the increased weight of your uterus and breasts and a variety of other things such as increased blood volume.
Dieting Risks
When you diet for weight loss, by definition, you're providing your cells with fewer nutrients than they need to sustain themselves. This forces your body to pull from your fat reserves to make up the energy difference. Your fetus has no fat reserves as it develops, however, meaning that it's very easy to create nutritional deficiencies in your developing baby by denying yourself calories. Further, when you limit calories, you also limit vitamins, which are critical to fetal development.
General Guidelines
In general, if you're concerned about your weight during pregnancy, talk to your obstetrician. Many doctors prefer that you eat a healthy, balanced diet and seek to either reduce the rate at which you're gaining weight or avoid gaining weight rather than attempting to lose weight during pregnancy. Drs. Roizen and Oz note that both overeating and undereating increase your developing baby's risk of obesity later in life, making a healthy diet during pregnancy important to you both.
References
- "You: Having A Baby"; Michael Roizen, M.D. and Mehmet Oz, M.D.; 2009
- American Pregnancy Association: About Pregnancy Weight Gain
