Dietician Robert Quigley said that even with degrees in nutrition and food science, he still "brought the wrong food home from the supermarket".
"We keep saying it's about personal choice and people [being able to] look after their health and well-being.
"But we need to provide them with the ability to make those good choices."
A Herald survey of shoppers at a Grey Lynn supermarket found people's grocery trips were complicated by the need to decipher labels on goods.
Lexia Bell-Kerr said products' healthiness were disguised by meaningless phrases like "Lite" and "99 per cent fat-free", which did not given an indication of their true qualities.
Lisa Brunel said she spent nearly all of her 30-minute shopping trip poring over labels.
"It's very hard to tell what is the healthiest thing. I usually look for a health tick, but we could do with something which told you quickly how healthy it was, and what country it is from."
She suggested a shift to the "traffic light" labelling used in the United Kingdom.
In April, food manufacturer Sanitarium proposed that New Zealand adopt the red, amber and green labelling system to eliminate consumer confusion.
The traffic light labels told consumers whether they should eat a food item often, occasionally or sparingly. They were also used to reinforce numbers showing whether foods have healthy, neutral or unhealthy proportions of fat, saturated fat, sugar and salt.
Dieticians and some political parties supported the idea, but most food producers were reluctant to adopt the new system.
That move and 60 other recommendations were being considered by the transtasman council of state and national food ministers for decisions this year.
Mr Quigley said: "Everyone has a role to play and at the moment nobody is putting it high on their agendas. That includes government, food producers, universities and food consumer groups."
Australian research published in April found confusion over "best before" and "use by" labels led to New Zealanders needlessly dumping $750 million of food a year.