Pregnancy
I recently discussed the role of carbohydrates during pregnancy in an episode of The Ancestral RDs Podcast. The most important reason why women need adequate carbohydrates during pregnancy is to ensure adequate fetal brain development and growth. Another reason is because a high protein diet can be dangerous during pregnancy, and when you cut out carbohydrate as a major macronutrient, you usually can’t help but increase protein as a percentage of calories. Protein intake greater than 25% of calories during pregnancy may lead to decreased mass at birth and increased perinatal morbidity and mortality for the baby.
The Institute of Medicine recommends a minimum of 175 grams of carbohydrates per day during pregnancy, which is 29% of calories on a 2400 calorie diet. Paul Jaminet advises pregnant mothers to restrict protein to about 15% of calories and to obtain 30% of calories as carbohydrates. Chris recommends a moderate carb approach for most pregnant women (except those with any type of diabetes) in his book, Your Personal Paleo Code (published in paperback as The Paleo Cure in December 2014).
Like these other experts, I generally recommend 30% of calories from carbohydrates for my pregnant clients, and also for those who are struggling with fertility. Unless you have diabetes or a serious neurological condition that requires carbohydrate restriction, it’s not worth the risk playing around with a low carb diet when you’re pregnant, and these diets aren’t conducive to fertility for many women either. (If you’re interested in more reasons why carbohydrates can affect fertility, read this great post by Stefani Ruper.)