Younger Australians are cutting back on things they need as well as things they want, as rising rents and home loan repayments force them to make tougher spending decisions than older people who have more savings, new research shows.

CommBank spending data shows Australians on average are slowing their discretionary spending as interest rates and consumer prices rise, but the 25-29 age group is the only one that is also spending less on items considered essential.