The objective of this article is to gain a better understanding of firms strategies towards nutritional tax policies and to assess their impacts from a public health point of view. We determine how new products that are nutritionally improved can successfully emerge in an asymmetrical context in which firms do not have the same strategic incentives to change the characteristics of their products. The results show that nutritional regulations may induce changes in the product quality choices by firms, but may also affect the competitive game. Under some conditions, the economic distortions are not compensated by increased health benefits.