Nonalcoholic fatty liver disease (NAFLD), a metabolic disorder related to insulin resistance and metabolic syndrome, has become a public health concern. Currently, the principal therapeutic modalities targeting NAFLD are lifestyle interventions. However, the efficacy of long-term lifestyle interventions in managing NAFLD remains largely unexplored. This study aimed to evaluate the efficacy of long-term lifestyle interventions in middle-aged and elderly men with NAFLD. All 280 eligible patients were randomized to the control or test group. Patients in the test group received counseling on diet and exercise from 2 physicians every 3 months via a phone call. Patients in the control group received only counseling in annual checkups without regular intervention. After the 2-year periodic intervention, body weight, abdominal circumference, ALT, TCH, LDL-C and HDL-C decreased in the test group. Specifically, the fatty liver index (FLI) and NAFLD-fibrosis score (NAFLD-FS) reduced markedly in the test group. However, in the control group, there was only a significant decrease in LDL-C, HDL-C and NAFLD-FS (P < 0.001). The liver steatosis grade of the test group decreased significantly, while it increased in the control group. In NAFLD, long-term lifestyle interventions exert an anti-obesity effect and attenuate liver dysfunction and steatosis.