The marketing director wanted to see how mimicking weight loss commercials from the post-war era would connect to the audience. This scripts mirrors a commercial from the early 1950’s, making allowances for new legal language. The spot itself sought to engage audiences through a cheerful tone. Ultimately it performed very poorly.
In retrospect, the commercials that performed the best (without celebrity endorsement) had a lot of fast edits, graphics, and claims. They gave the appearnace of authority, which is likely how they drove results. However, at the time, the product was not approved by the FDA and any semblance of authority potentially put the company at risk.