FROM SUGARS TO GRAINS: PUSHING FOOD INDUSTRY CHANGE

Nutritional scientist Dr Lisa Te Morenga (Ngāpuhi, Ngāti Whātua, Te Rarawa) is the latest recipient of the Royal Society’s Hamilton Award – for excellence in research over the course of an early career.

PHOTO: VICTORIA UNIVERSITY OF WELLINGTON

Driven by a desire to make a difference in Māori health, Lisa Te Morenga completed a PhD nine years ago investigating the effects of diet composition on diabetes risk, then began researching the effects of sugars on bodyweight.

Her reviews and studies have been influential, with one paper used by both the USDA (United States Dietary Guidelines) and the EFSA (European Food Standards Association).

Lisa says, “People think sugar is the evil, toxic thing, but as nutritionists we know that dietary intake is more complex. There was this whole movement a few years ago, where people were saying sugar caused the obesity epidemic and diabetes, and fat had been unfairly maligned. And it’s more complicated.”

One thing her early work showed was that, unlike claims to the contrary, there was nothing metabolically special about sugar in terms of how its calories contributed to body weight. It sounds like a simple finding, but it has enormous implications.

“If you turn around now and blame sugar for everything, we’ll see a proliferation of junk foods that are high in fat and low in sugar. We won’t be better off, because the issue is junk food in general, or ‘discretionary foods’, and not eating enough healthy foods. We do eat a lot of sugar. But we also eat a lot of discretionary fat, salt, and refined carbohydrates.” For example, “If all you did was brought in a sugar tax to get people to reduce soft drink intake, I don’t think it would be effective. We need multi-factorial public health strategies.”

She adds, “It’s not just about getting consumers to make healthier choices. You need the industry to buy into it too. They’ll respond to the consumers, but they can also drive what the consumers choose.”

Essentially, says Lisa, “we’re all eating more than we need, and not exercising enough. If I think back to the food portions my family served when I was a teenager, they were smaller. Cakes were smaller. And supermarkets weren’t open all the time. We’ve got used to things getting bigger and bigger, and more food around us all the time.

“I don’t think there’s any magical nutritional solution to our health and obesity crisis, but everyone wants one.”

WORKING WITH WHO

Lisa has had a policy of saying yes to opportunities. “For early career researchers, if you’re brave and you take those, even if you’re not quite sure, they can lead you places you might never have anticipated.”

As a result of her sugar research, “I was invited to World Health Organisation (WHO) meetings to present on the work and then to actually contribute to drafting their nutritional guidelines on free and added sugars.”

It was a fascinating process. “If you’ve ever seen the WHO guidelines, they’re very simple. They basically say ‘adults and children should consume less than 10% of their energy intake from free sugars.’ But it’s amazing how long it can take to construct that. “The panel debates how every word could be interpreted. Like, ‘Hmm … in countries where intakes are already below 10%, we don’t want them to think they can increase their sugar intake …’ I went to about four meetings, four days each, all around the world, where we just worked constantly, reviewing evidence, updating reviews, discussing the nuances. It was great.”

FINDING THE BEST FIBRE

Lisa is now focusing on dietary fibre. “Earlier this year, we published a big systematic review looking at the effect of fibre and carbohydrate quality on health. It’s a key piece of evidence that will sit behind the carbohydrate review that WHO are working on at the moment.

“It shows that high-fibre intakes are associated with lower risk of most chronic diseases. That’s useful, because people have been quite anticarbohydrates, but you don’t get fibre in anything other than carbohydrates. So carbs aren’t that bad for you, if it’s high-fibre, wholegrain stuff.” However, the word “wholegrain” is tricky. “I’ve got PhD students who are clarifying that we need to pay attention to the structure of the grain in wholegrain foods, not just the composition.”

This is to do with how processed it is. “Most food standards around the world define ‘wholegrains’ based on the ‘composition’ of the food. That is, if you call something a wholegrain it’s got to have all the constituent parts of a grain in approximately the same proportions as you’d find in the original grain. But it doesn’t matter if that’s completely powdered or if it’s the actual wholegrain with its original structure.

“In the late 1980s, some researchers showed that it looked like the structure was important, but no one repeated that work and it wasn’t adopted into recommendations. Now everyone wants to healthwash their food, so there are all these foods called ‘wholegrain’ that don’t look like they’ve actually got any real whole grains in them.”

This is important. For example, “It’s looking like, for people with diabetes or pre-diabetes, it’s particularly important to look for less processed wholegrains. They’re more resistant to digestion, which means they release the glucose slower. “Breadmakers are interested in this research because they’ve seen bread come under threat from the low-carb movement. They’re interested to see how they can make bread healthier. I’m interested in it from a public health point of view because bread is cheap and environmentally sustainable.”

“Breadmakers are interested in this research because they’ve seen bread come under threat from the low-carb movement. They’re interested to see how they can make bread healthier. I’m interested in it from a public health point of view because bread is cheap and environmentally sustainable.”