6564
Mice fed ad lib . on any of the palatable diets were heavier , fatter and had higher blood leptin than controls , and had reduced NPY and increased cocaine - and - amphetamine - regulated transcript mRNA in the ARC .
 Chemical: cocaine; Chemical: amphetamine
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: cocaine; Chemical: amphetamine