What is the management of nash and nafld in 24 y bmi of 19.5 healthy male no alcohol or meds or anything synthetic, even home made food?

Nto specific: In general the rx of NASH is typically to control factors that make it worse: 1) treat and control diabetes if present, 2) maintain a normal body weight, 3) correct high cholesterol and elevated triglycerides in the blood with diet and or medicines.

NASH treatments: At this time NASH is very hard to treat - avoiding obesity, avoiding alcohol and other liver injuring disease like hepatitis are the mainstays to avoid progression. Severe cases are usually good candidates for transplants.

No standard: The key will of course be increasing your level of aerobic fitness. I trust the diagnosis is right & that other causes of fatty liver / elevated enzymes (especially hepatitis c) have been ruled out. I hope you will not let somebody's idea that "synthetic is bad" limit your willingness to take medication. Betaine in beet juice, and of course vitamin e, are things to talk about with the team.