Marketing research shows that soft drinks with “diet” in the name are not that popular with male consumers because they associate the word with food / drinks for women.
The “Wild Health” Coca Cola ad (starring Japanese singer Namie Amuro) seems to be aimed more at Japanese men.

This ad, like many Japanese ads, uses English even though many people in the target audience may only have some understanding of what the text means. English is used because it is “catchy” and to some viewers in Japan it may make a product seem more international / exotic / unique.
Essays on May 2021 TOK essay prescribed title #2 are based on investigating differentiating between change and progress. This Coca Cola ad has different aspects of change and progress:
- Whether the move from Diet Coke to Coke Zero is progress or not
- How the introduction of sugar free soft drinks could be viewed as progress from one perspective but as just change from another
- How the use of English in advertising in Japan could be viewed as progress / not progress