Study of Kiwi diet reveals good, bad and ugly

Family eating dinner
The study showed that in some ways we're eating better, in some ways we're getting worse. Photo credit: Getty

An MPI-led study has revealed the good, bad and ugly about the modern New Zealand diet.

The 2016 New Zealand Total Diet Study (TDS) tested over 4000 food samples to get a better understanding of what Kiwis are ingesting from farms to the supermarket.

Dr Andrew Pearson from the Ministry for Primary Industries told RadioLive's Home & Garden that the food samples were all prepared as a normal Kiwi family would prepare it.

The bacon was fried up and vegetables boiled before the researchers measured chemical and nutrient levels.

The study provided good news for iodine levels, which are now back to healthy levels for the first time in decades. Dr Pearson attributes the iodine levels to bread fortified with iodised salt.

"It was one of the real success stories of this study," he told RadioLIVE.

When co-host Helen Jackson asked whether non-organic foods should be a concern, Dr Pearson assured her that levels are not even close to dangerous.

MPI researchers tested for over 300 agricultural chemicals and 20 herbicides contained in the food samples.

"Certainly, [the chemicals are] there. There are certainly residues in the diet," Dr Pearson says.

But he said "there isn't a dietary risk" for those who eat non-organic foods, with the levels of chemicals and herbicides in diets across all age groups well below safe levels.

"Even if you look at the mixture of chemicals across the diet, it's not something Kiwis need to be concerned about because it's still far below these safe levels."

The study wasn't all good news, with sodium levels about the same as they were in 2009. Dr Pearson explained that excess sodium was primarily linked to the processed foods in the study.

"We are getting far too much salt for nutrition reasons," he said.

He pointed out that the study doesn't account for extra salt added by Kiwis in the kitchen, which is a problem that MPI is keeping in mind. A high-sodium diet can lead to various health risks, including high blood pressure.

Aluminium levels were also higher than expected, though Dr Pearson told RNZ that these levels are not high enough to cause harm.

MPI will work with the food industry to reduce an additive called sodium aluminium phosphate that is typically added to baked goods.

Trace levels of lead have continued to drop over time, which Mr Pearson said is very good news. His team believes that the Kiwi diet is close to containing levels of lead that would naturally occur in the environment.

MPI runs the thorough study every five years.

Home and Garden with Tony Murrell, 7am - 10am Saturday and Sunday mornings on RadioLIVE and streaming live to the rova app on Android and iPhone.