The investigation addresses a randomized, parallel, long-term personalized nutritional intervention with two strategies: 1) Control diet based on American Heart Association (AHA); 2) Fatty Liver in Obesity (FLiO) diet based on previous results (RESMENA project).The diet is based on macronutrient distribution, quality and quantity, and is characterized by a low glycemic load, high adherence to the Mediterranean diet and a high antioxidant capacity, with the inclusion of anti-inflammatory foods. It also takes into account the distribution of food throughout the day, number of meals, portion sizes, timing of meal, individual needs, dietary behavior (behavioral therapy: eat slowly, teach what to buy, what to eat, when to eat). The participants are instructed to follow this strategy. This strategy (RESMENA) was even more effective than AHA after 6 months follow-up, in terms of significant reduction of abdominal fat and blood glucose level. In addition, this diet had beneficial effects for participants who were obese and had values of altered glucose, reducing significantly in RESMENA participants LDL-oxidized marker. These results are very important to apply in the present investigation since that patients with NAFLD are commonly insulin resistant.