Public Health

Professor Grant Schofield and Dr Caryn Zinn,
Auckland University of Technology. 2013

Prof Grant Schofield

Schofield is director of the Human Potential Centre at AUT and does ongoing research into physical activity-based research that includes nutrition. Schofield also had a Damascus moment, in the Pacific Islands.

In Vanuatu, the people eat the same way they have for decades - on fresh produce they grow or catch themselves - mainly fish, vegetables and coconuts. The population were healthy and happy.

About 60 per cent of their calories come from fat, more than double the average New Zealand intake. There was very little carbohydrate, just a small amount of rice.

On Kiribati, the islanders survive on a staple of cheap imports such as soft drinks, white rice, flour, sugar, tinned fish and instant noodles.

The people rely heavily on foreign aid, nearly all the adults were overweight or obese. The children were malnourished. Rampant diabetes meant the hospital was amputating up to 20 limbs a week.

"That's when the penny dropped," Schofield said. "Two islands - The difference? The food. Specifically, the amount of carbohydrates. If you ever wanted evidence that processed carbohydrates damage humans, you should go to Kiribati and have a look for yourself.

Together they wrote a book called “What the Fat: Fat's IN: Sugar's OUT,” 2015

and a new one called “What the Fat: Sports Performance,” 2016

Dr Caryn Zinn

A Damascus Moment

Zinn says she was “very loyal” to mainstream low-fat, high-carb dietary guidelines.

Schofield came across some old high-fat related research, five years ago, and asked her opinion.

She almost said. “Take your low-carb diet and go somewhere else. I am the dietitian and I know."

Instead, Zinn scrutinised the research. She was soon “flabbergasted” to realise that everything she had learned and thought she knew about diet and nutrition was wrong.

“The evidence that led to mainstream dietary guidelines was largely observational, correlation-based research,” Zinn said. “From a quality viewpoint, it did not compare to the solid, randomised controlled trials (RCTs) that were available to support low-carb, high-fat diets.”

Zinn in her practice worked with many who weren't able to maintain the weight loss. She began to realise that there was good reason: They were constantly hungry because they were eating too many carbohydrates and too little fat.

Part of that realisation involved understanding why carbohydrate really isn't an essential nutrient.

Zinn also realised that fears about low-carbohydrate and ketogenic diets, that worried her, were “just scare mongering”.

As a consequence, Zinn said: “I'm embarrassed to say that I used to teach my students that low-carbohydrate diets were bad because ketosis was bad.”

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