If your liver enzymes are high could this be because of a fatty liver?

Yes, a fatty liver will cause a rise in liver enzymes (as determined by a blood test). However, all other liver conditions will also cause a rise in liver enzymes, so concluding it is due to "fatty liver disease" purely on the the basis of high ALT/AST levels would be foolish. Some liver diseases can be ruled out on exactly how high the enzyme levels are (some require very high levels, and at certain ratios), however that still leaves quite a few possible causes for high liver enzymes.

If your liver enzymes remain high, or if you are experiencing other symptoms of liver disease (e.g jaundice, itching, tiredness, indigestion possibly with upper back pain, stabbing pain in either side of the abdomen etc...) , you will be sent for further testing to identify the exact cause of the liver malfunction, and advised as to appropriate treatment. However you may also find that your liver enzymes stabilise by themselves, without need for treatment.