There is somewhat of a craze about Raw-food diets going around recently, including some of my friends that have gotten into it. For an adult it is their prerogative, what they put in their stomachs, but a child has different nutritional needs from a full grown adult. I was wondering if there is any research or information on the effects of feeding a child (say 1-10 years old, after weaning) a raw food diet.
This entirely depends on the specifics of your 'raw food' diet.
Many people use raw food diets to describe a diet that is very low in artificial sweeteners, preservatives, and other non-natural additives. Others use it to describe a diet where you simply don't cook anything. One makes sense, another absolutely does not. Finding research specific to your question is going to be very difficult, though. The annoying thing is that the question of whether a raw-foods diet is healthier for you is one of the easiest things to answer, but one of the hardest things to prove. Everything we know about the body points away from using the over-processed junk that's wormed its way into our food supply over the last 80-90 years. However, proving that this junk causes diseases in a controlled study is practically impossible because there are so many variables in human digestion that can't be properly isolated and eliminated. Even if you were to sustain an experiment group completely on TV dinners and noted a huge uptick in cancer rates, there's no way to say for certain what ingredient or system of ingredients in the TV dinners did it, or even that the experiment group wasn't just more prone to cancer to begin with.
The best one can do at this point in time is to look at the what facts we do know about the human body decide what to believe for yourself. To more fully answer your question, I'll go over a few variations of 'raw foods' diets with some rationales you should find fairly simple to verify or disprove on your own. I would link a ton of websites but most of my learning comes out of textbooks given to me by health professionals - I can't easily make it available for Internet consumption due to logistics and copyright laws.
"Basic" raw foods diets, where one simply cuts out things like high fructose corn syrup, preservatives like sodium nitrate, bleached white flours, and so forth should perform very well in children. Meat is cooked and consumed in this diet, and grains are used in a balance with everything else (instead of eaten heavily, like the 'food pyramid' plan). So, these are basic foods like spinach, eggs, milk, ham, beef, nuts, whole-wheat bread, and natural corn. There is no reason why this would not perform well in children because their digestive systems are getting precisely what they expect to get; nothing more and nothing less. The foods in this diet have been consumed for hundreds or thousands of years and there is absolutely no evidence of harm coming to their consumers (excepting special cases such as food allergies). The range of allowed foods provides all the things the body has been known to need, and a largely unaltered state. A variation of this one is the "vegetarian" raw foods diet, where one doesn't eat meat but does consume animal by-products like milk and eggs. This one needs a little more vigilance due to the voracious vitamin needs of children, but again does not pose any particular deficiency.
A "Vegan" raw-foods diet has a few warning signs on it. In this diet, no animals or animal by-products are consumed. In adults, this can work alright if the adult does not have a big need for physical conditioning or labor. In children, muscle, bone, and sinew gains are guaranteed. The entire vitamin B complex is crucial for the growth and maintenance of these things and a vegan diet is critically deficient in it. A vegan diet can procure some parts of the B complex, but you cannot get significant quantities of real, natural B12 without consuming animals or animal by-products. B6 is also difficult to obtain in sufficient quantities to support a youthful growth spurt, though adults have much less trouble getting enough. "Vegan" supplements of B-vitamins are often derived from mineral or crystalline sources that your body cannot digest at all, so these too are no substitute. An 'herbivore' diet such as this one also doesn't make a huge amount of sense from a physiological standpoint. Most herbivores have intestinal tracts that are around 10 times their length from hip to shoulder. Humans fall short of this, usually around 6-8 times. Humans also lack the multi-chambered stomachs and specially formulated enzymes that most pure herbivores have to get the most out of their food.
A "pure" raw-foods diet would be what Barbie was talking about above. Meat is eaten, but it is not cooked and eaten raw like everything else. For now, let's ignore the multitude health risks from routinely eating uncooked meat (as a matter of fact, I think this would be construed as child endangerment in many states in the USA). The practice of eating raw meat doesn't make sense from a cursory look at the human digestive tract. Compared to a pure carnivore, such as a lion, our average stomach pH is much closer to neutral and our intestines themselves have a smaller diameter, providing less surface area for partially digested meat chunks to be absorbed. Cooking is what allows us to get the maximum amount of nutrition out of meat for the least amount of risk. In fact, there are some theories that the extra nutrition from cooking is part of what made humans smart enough to form societies in the first place. Children have a very pronounced need for that extra nutrition, as they are physically growing on a near daily basis. Presenting that nutrition in an inherently harder to digest format does not seem to be a terribly rational thing to do.