Hi.
Thanks for posting query at HCM.
Value of AST or 
ALT greater than 85 or above maybe investigated further.
HAV, 
HBV, 
HCV, Alcohol ingestion , obesity are common causes of 
liver disease.
Rule out HBV and HCV
Usually ALT or AST values higher than "two times the upper normal limit", is considered abnormal ( in some countries, ALT or AST values of more than 100 are considered abnormal). 
advice for fatty liver:
- abstinence from "Alcohol" 
- LOW fat diet should be followed, AVOID junk food and beverages
- decreased oil consumption (oily food)
- NO red meat
- green vegetables should be ingested daily
- use lemon juice (lemonade) once in a day
- reduce weight if overweight/obese
-"recheck liver enzymes after 6 to 8 weeks" and/or 
ultrasound.
any further questions are welcomed.
hope to answer your concern.
wish you good health.
regards,
Dr Tayyab Malik