The Centers for Disease Control and Prevention's (CDC) study, which is said to be the first government estimate of the number of children who do not eat meat, showed that 367,000 children in the US are vegetarian.
This figure is estimated to be about in one in 200 children and it is animal welfare, not health, that most often causes kids to stop eating meat, according to Richard Schwartz, president of Jewish Vegetarians of North America, who was quoted in an Associated Press report.
However, experts claim that children who are vegetarians could lack essential nutrients if they don't eat meat, such as protein. Therefore it is important to eat alternative sources such as soybeans and nuts.
This is more the case for vegans who do not eat dairy produce or meat.
The research adds weight to a separate report published last year by Business Insights - called "Ethical and Wellness Food and Drinks for Kids" - which said that children are becoming more aware of environmental issues from an earlier age.
This found that the main drivers for parents when purchasing ethical food and drinks for their children were environmental, food quality and food safety.
It said that increasing awareness of environmental concerns, such as animal welfare, means parents are purchasing these products to feel they are doing good, and are pushing these ideals onto their children.
In the US there will be 20.8 million 5-9 year olds by 2011, compared with 19.6m in 2006.
The CDC report which presents selected estimates of complementary and alternative medicine use among US adults and children, using data from the 2007 National Health Interview Survey, conducted by the CDC's National Center for Health Statistics.
The results were based on over 9,417 interviews for children aged up to 17 years.
The report defines vegetarian diets as those totally devoid of meat, red or white.
However, it said there are numerous variations as, for example, some vegetarian diets are restricted to plant products only, while others may include eggs and dairy products.
Another variation limits consumption to raw fruit, sometimes supplemented with nuts and vegetables. Also, a number of vegetarian diets prohibit alcohol, sugar, caffeine, or processed foods.