As adults, it can be overwhelming wading through the varying opinions on how many carbohydrates we should eat. Many of us with a history of being overweight find that low to moderate carbohydrate consumption works very well for us. Many others find success at either of the extremes of paleo carbohydrate intake: ketosis versus plenty carbohydrates from “safe starches”. This is why I wrote my 3-part series on Optimizing Carbohydrate Intake for Your Body (see here, here and here). However, this opened up the question from many of you: what about kids?
In general, I’m not a big fan of counting macronutrients for kids (or anyone, if you can get away with it). If you present your child with a variety of healthy foods, most kids will naturally eat what their body needs to be healthy. However, it is the natural tendency of parents (especially parents who are trying to address their own health issues with a paleo diet) to worry about whether or not their child is getting the right amount of, well, just about everything. It is also helpful to have some guidance as to what exactly you should put in front of your kids. For example, is it healthy to let them eat as much fruit as they want? I know my kids would gladly eat fruit all day!
When it comes to macronutrient ratios for kids, I think we can get a very good idea of how they should be eating by looking at the composition of human breast milk. In prehistoric cultures, children likely received at least some breast milk until the age of 4 or 5 years, so it’s a pretty safe bet that the macronutrient ratio of breast milk is a good guide at least for kids up to that age. Milk is considered the perfect food for growth of a young child and I believe that we can continue to use the macronutrient ratio of breast milk as a general guide for the diets of our children for as long as they are growing (after all, the macronutrient ratio of breast milk is often used to as a guide for carbohydrate consumption for adults!).
The macronutrient ratio of human breast milk is quite variable, depending on the diet of the mother, the amount the baby nurses, and the age of the baby. There seems to be some signaling from the baby to the mother, and it is very likely that much of this variability reflects the specific dietary needs of the baby at that time. The carbohydrate content of human breast milk varies between 57% to 70% (as a percentage of total milk solids). Fat makes up 28-39% of milk and protein makes up about 7-10% (as a percentage of total milk solids) . Translating this to a percentage of caloric intake (which is a far more familiar number for most of us) the carbohydrate content of human breast milk is 40-55%. When these numbers are used to provide guidelines for adult carbohydrate consumption, an amount of glucose needed by the growing brain of a baby/child is subtracted (which is why The Perfect Health Diet ends up with a recommendation closer to 20-30% carbs for adults). We don’t need to go to these lengths here (phew! because this has already been enough math for me for one day!) because kids brains continue to grow and develop, even until their mid-twenties (sorry if I just offended anyone in their early- to mid-twenties by calling them kids).
Your child’s carbohydrate need will probably vary with growth spurts, developmental spurts, and age. On average, their carbohydrate needs will probably tend to go down as they get older (protein especially will take its place). Caloric intake varies dramatically with growth spurts, developmental spurts and age as well, so it’s tough to convert this to a number of grams of carbohydrates your kid should be eating. Instead, think of it this way: to achieve 40% of their calories from carbohydrates, something like half to three quarters of their plates should be fruit and vegetables (including plenty of starchy vegetables). The reason why 40% of calories from carbohydrates doesn’t just translate to 40% of their plate being fruits and vegetables is because non-starchy vegetables are not very carbohydrate/calorie dense (especially compared to whatever fat you may also have on the plate).
The point of this post isn’t to get you counting the carbohydrates your child is eating, but rather to point out that quite a lot of fruit and vegetables is just fine for your growing child. And as long as they are eating some of their meat and healthy fats and you are presenting them with a variety of healthy food options (think meat, fish, organ meat, healthy fats such as avocado, olives, and coconut oil, green veggies, colorful veggies, cruciferous veggies, starchy veggies and all kinds of fruit), it’s probably not worth worrying about.