- Overweight/obese (BMI over the 85th percentile) male and female adolescents (age range 10-17) with elevated serum aminotransferase levels, diffusely echogenic liver via ultrasound suggestive of fatty liver, and/or prior diagnosis of NAFLD. Participant eligibility will depend on the ability of one parent to attend the initial diet instruction and individual counselling sessions with the registered dietitian during week 2, 4 and 6 of the diet intervention.