SCD is a wonderful diet because it reflects how mankind origionally ate.
"The Specific Carbohydrate Diet™ is biologically correct because it is species appropriate. The allowed foods are mainly those that early man ate before agriculture began. The diet we evolved to eat over millions of years was predominantly one of meat, fish, eggs, vegetables, nuts, low-sugar fruits. Our modern diet including starches, grains, pasta, legumes, and breads has only been consumed for a mere 10,000 years. In the last hundred years the increase in complex sugars and chemical additives in the diet has led to a huge increase in health problems ranging from severe bowel disorders to obesity and brain function disorders. We have not adapted to eat this modern diet as there has not been enough time for natural selection to operate. It therefore makes sense to eat the diet we evolved with."