The most common form of chronic liver disease, recently defined as MASLD, is strongly linked to obesity and metabolic syndrome. Lifestyle changes are part of MASLD prevention. The very low-calorie ketogenic diet (VLCKD) is a useful option for treating MASLD and reducing liver steatosis in patients with obesity. We assessed whether a greater degree of steatosis could have a positive or negative impact on how well 8 weeks of using the VLCKD improve steatosis and fibrosis in a patient population of overweight and obese individuals. Anthropometric parameters, along with changes in hormone and metabolic biomarkers, were also assessed both before and after the dietary change. The study population included 111 overweight (14.41%) or obese subjects (85.59%) aged between 18 and 64 years; the 75 women and 36 men involved were not taking any medicine. In both the raw (0.37 95% CI 0.21; 0.52) and the multivariate models (model a: 0.439 95% CI 0.26; 0.62; model b: 0.437 95% CI 0.25; 0.63), there was a positive and statistically significant correlation between the CAP delta value and the CAP before using the VLCKD. Additionally, the liver stiffness delta was found to be positively and statistically significantly correlated with liver stiffness before the use of the VLCKD in both models: the multivariate model (model a: 0.560 95% CI 0.40; 0.71; model b: 0.498 95% CI 0.34; 0.65) and the raw model (0.52 95% CI 0.39; 0.65). Systolic and diastolic blood pressure, insulin resistance (measured by HOMA-IR), insulin, HbA1c, fasting blood glucose, total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides, BMI, waist circumference, and fat mass, were all decreased (p < 0.001) following the use of the VLCKD. However, following the use of the VLCKD, there was an increase in vitamin D levels. (p < 0.001). We found that using the VLCKD for 8 weeks has a greater effect on improving steatosis and fibrosis in subjects who initially have more severe forms of these conditions.