Staff and councillors or people attending events could be able to bring their own sugar-sweetened beverages while hot drinks and alcohol will be exempt from the guidelines.
Council's research and engagement advisor Alex Staric's report said there was an opportunity for council to show leadership in public health.
But it also highlighted a number of risks including being seen as encroaching on personal choice, impacting the success of events and that the guidelines "may not contribute, or only marginally contribute, to influence positive health outcomes".
Whanganui mayor Hamish McDouall believed despite not going for a policy, guidelines could have a genuine impact.
"A lot of things begin as not enforced and unenforceable (but) that's the best way. If you can get buy-in from the population, that's a great start," he said.
McDouall said the guidelines still had to be written and come back to council but as a leadership organisation it should be setting an example for others to follow.
It was not about telling people they can't purchase their own but not making them available would put council in a position to influence, he said.
In an unscientific public poll of 220 people, more than 40 per cent favoured the introduction of guidelines while 27 per cent favoured neither a SSBP or guidelines.
Council will work with Healthy Families and the Whanganui District Health Board to develop the guidelines. In 2017 council decided to investigated a (SSBP) after a remit was adopted by Local Government New Zealand.
Only five councils have adopted a policy with two writing guidelines so far.