PurposeThis study aims to show how market orientation (MO), brand (BR) and business strategy (cost leadership strategy and differentiation strategy), which play mediating and moderating roles, respectively, can increase competitive advantage (CA). With a focus on brand, market orientation, cost leadership strategy (CS) and differentiation strategy (DS), as well as an analysis of variance control on varying business sizes per business seniority, the current study made a theoretical contribution.Design/methodology/approachAn empirical study was created using a quantitative methodological technique. The surveyed data were collected from 379 managers or owners who participated in a face-to-face survey at different food processing companies in Vietnam. To test the hypotheses, the gathered information was examined utilizing multigroup analysis and partial least squares structural equation modeling.FindingsThe brand was found to have the greatest positive impact on competitive advantage, followed by a business strategy that positively influenced competitive advantage, and, finally, business strategies that significantly moderated the third strong positive impact between market orientation and competitive advantage. Market orientation has the fourth strong positive impact on competitive advantage, whereas brand has the lowest positive impact on market orientation.Originality/valueThis is the first investigation, according to the authors’ knowledge, into the role of market orientation as a mediator in the relationship between brand and competitive advantage in addition to the regulatory role of business strategy at two strategic levels: cost leadership and strategic focus as well as the difference between competitive advantage and market orientation in the Vietnamese food sector.