Read the following excerpt from a satirical novel:
"In a world where everyone prided themselves on their health, Mary proudly flaunted her capacity to consume whole pizzas and mountain-sized sodas in a single sitting, declaring loudly, 'This is the path to true vitality!'. The townsfolk, perplexed yet intrigued, nodded with solemn agreement, convinced they had discovered a new lifestyle trend to follow."
What form of irony is predominantly showcased in this excerpt?