Sunday, November 03, 2013

Never, ever, take dietary advice from the soft drink industry

It is reckless with the truth

Never take dietary advice from the soft drink industry.

Remember Coca Cola’s infamous 2009 “myth-busting” campaign featuring the actress Kerry Armstrong? It said it was it a myth that Coke made you fat, a myth that it rots your teeth, and a myth that it was packed with caffeine.

The Australian Competition and Consumer Commission made it publish corrective advertisements about all three. "Coke's messages were totally unacceptable, creating an impression which is likely to mislead that Coca-Cola cannot contribute to weight gain, obesity and tooth decay,” the Chairman said at time.

The industry is at it again. But this time the message is more dangerous, precisely because it sounds more believable.

Three leading health organisations - Diabetes Australia, the Heart Foundation and the Cancer Council - banded together this week to to run a television ad which shows the 16 teaspoons of sugar in a 600ml bottle congealing into fat as they enter a drinker’s body.

They want vending machines banned from schools, the sugar content cut, and the manufacturers to “stop promoting the message that high-kilojoule beverages are part of a healthy, balanced diet”.

I don’t like their chances. Appearing on ABC News 24 to respond the chief executive of the Australian Beverages Council Geoff Parker spoke instead of “getting people to understand the concept of the total diet”.

According to the Beverages Council, “all kilojoules matter, it doesn’t matter where those kilojoules come from.”

What matters is “energy in and energy out - what it really comes down to is that people will put on weight if they consume more kilojoules than they expend through physical activity”.

It’s simple, and it turns back clock on dietary science thirty years. It was indeed once thought that all fuels were much the same. It didn’t matter what you poured down your throat - if you poured in less you would get thin, if you exercised more you would burn it off and get thin.

It’s still definitionally true, but it tells us nothing about the way different types of fuel affect our compulsion to pour things down our throat and our ability to burn fuel off.

Carbohydrates - especially sugar - are special. Science journalist Gary Taubes outlines our emerging knowledge of them in his two latest books Good Calories, Bad Calories and Why We Get Fat.

Human beings grow because we secrete hormones. Insulin is one of them. Sugar fires up insulin.

Here’s what happens when we take in several teaspoons of sugar (there are 16 in a 600ml bottle)...

Insulin and associated chemical messengers intercept whatever fat we are digesting before it gets to our bloodstream and stash it wherever they can, often pumping it into fat cells. At the same time the substances that allow fat to leave our fat cells get scarce. Fat gets locked in to the cells. It becomes temporarily unavailable. We feel weak and hungry. If we are unlucky we’ll reach for more sugar.

As Tabes puts it: “We don’t get fat because we overeat; we overeat because we’re getting fat.”

(Some of the sugar also gets directly turned into fat in our livers as the television ad indicates, but the more important effect is that insulin helps push other fat into our fat cells and temporarily prevents it getting out.)

As with most science there’s room for disagreement. The mechanism is more complicated than I have just described and it is not yet fully understood. But what is known - for certain - is that fuels ain’t fuels. Some fuels promote fat growth, hunger and sloth in a way others do not. They help determine whether it’s more energy in or more energy out.

Advising people to take care with “energy in and energy out” when your own product is making that difficult is particularly cruel, in my opinion.

And so too is parading misleading statistics (a bugbear of mine, I’ll admit). The Beverage Council says across all children the proportion of energy provided by soft drinks halved from 3.3 per cent in 1995 to 1.6 per cent in 2007.

It sourced that claim from a report that doesn’t make it. When I asked for the real source it provided another, an analysis that happens to have been funded by the Beverage Council itself, with extra funding to “write the manuscript by Coca Cola South Pacific”.

That report specifically says that two figures are not directly comparable. Among teenagers soft drink consumption climbs with age. The 1995 figure covers children aged up to 18 years, the 2007 figure only children up to 16 years.

The industry is reckless with the truth. It’s the last place you should turn for advice about your diet.

In today's Canberra Times, Sun Herald