Now it is one of the fastest growing developmental disabilities in the US. No one knows why but it is more common in boys than girls. 1 out of 54 boys and 1 out of every 252 girls are diagnosed with autism in the US. It is growing at a rate between 10% and 17% each year. Some experts believe the drastic change of diet in the last several decades may play a part in the rate of cases diagnosed. Sugar consumption, some experts, believe may be a causative factor and the reduction of healthy fats may also be responsible for the loss of healthy cognitive function.