What is the fine-grained topic of the following text: Gatorade Zero – PepsiCo’s sugar free version of Gatorade – is 'off to a great start', according to PepsiCo CEO Indra Nooyi; highlighting trademark Gatorade as a stronghold in PepsiCo’s North American Beverages Unit. Only return the topic.
The success of Gatorade Zero in PepsiCo's North American Beverages Unit.