This is a descriptive study which generally aims to assess the knowledge, attitude, and practice (KAP) in managing type 2 diabetes mellitus (T2DM) of among 32 adult outpatients in San Pedro City, Laguna. The study described associated factors with the KAP of T2DM outpatients. Sociodemographic, KAP, and food frequency questionnaires were used to obtain information. Results revealed fair knowledge (84%), good attitude (88%), and good practice (44%) in managing T2DM among respondents. The FFQ analysis revealed that the daily carbohydrate intake of most respondents came from white rice. For protein, egg and fish were consumed “3-4 times per week”. For fat, cooking oil was consumed “daily”. The median intakes per food group were deficient as compared to the DNG Pyramid recommendations. There was a positive relationship between attitude and practice. No association was observed between knowledge and attitude/practice. Age, employment status, and employment sector have a relatively strong association with knowledge level. Community-based nutrition education programs should be conducted to improve the knowledge in diabetes self-management of the T2DM outpatients in the study, and to improve their food choices as this can influence glycemic response.