The demise of the Danish fat tax

Posted on November 19, 2012 by Bill Shrapnel

As governments struggle to address the rising prevalence of obesity and other chronic diseases there have been increasing calls for taxation on selected foods as a means of improving the quality of national diets. Last year Denmark introduced the world’s first ‘fat tax’, but in an abrupt turnaround the much maligned tax has been repealed. What went wrong?

Targeted taxation of foods

The rationale for targeted taxation of foods to improve health draws on the fundamental economic principle that the demand for any good is related to its price. If the price goes up, the demand goes down, and vice versa. Hence the demand for goods is said to be ‘elastic’. Viewed through this prism, addressing diet-related chronic disease becomes straightforward – use the tax system to increase the price of junk foods and lower the price of healthier foods. Too easy.

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Sugar-sweetened drinks and obesity: threat, opportunity, or both?

Posted on November 7, 2012 by Bill Shrapnel

Following the failure of the ‘eat less fat’ strategy for addressing the obesity epidemic the focus has shifted to sugar-sweetened beverages. Will this approach be more fruitful? Is sugar the problem, or is it liquid calories? Or are we missing something obvious?

Two new studies recently published in the New England Journal of Medicine have shed further light on the issue of soft drinks and weight gain.

Two new soft drink studies

Ebbeling and colleagues studied 224 overweight and obese adolescents who regularly consumed sugar-sweetened soft drinks. Half the subjects participated in a 1-year program designed to decrease consumption of these beverages. Both this intervention group and a control group were followed up for a further year after the intervention was complete. After one year the mean body weight of those in the intervention group was significantly lower (1.9kg) than that of the control group, though significance was lost at two years. So the program worked while underway but its effects did not persist.

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Our Dietary Guidelines: better, but good enough?

Posted on October 22, 2012 by Bill Shrapnel

Following consultation with stakeholders, the draft Australian Dietary Guidelines have been further refined, with some improvements in relation to cereal fibre, trans fats and added sugar. Even the mess around saturated fats has been tidied up a bit, but is it enough?

The first post on The Sceptical Nutritionist highlighted several problems with the draft Australian Dietary Guidelines and these have been discussed in detail in recent months. Encouragingly, some of the issues appear to have been addressed during the consultation period. The clues come in a draft appendix to the Australian Dietary Guidelines that was recently released for consultation, which includes the latest version of the key Dietary Guidelines statements.

More emphasis on cereal fibre

There is now greater emphasis on cereal fibre. The previous statement that recommended cereal foods should be ‘mostly wholegrains’ has been changed to ‘mostly wholegrain and/or high cereal fibre varieties’. This is consistent with the science as many of the studies used to support the wholegrains recommendation used high fibre foods, suggesting that recommending high fibre cereal foods was equally valid.

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The Australian Paradox is confirmed: sugar intakes are falling

Posted on October 8, 2012 by Bill Shrapnel

Last year’s contentious finding that intakes of sugar in Australia have declined over recent decades as obesity rates rose was attacked mercilessly, but the publication of a new report has vindicated the researchers.

In the last few years sugar has become public enemy number one in the fight against obesity. Not only is sugar supposedly making us all fat, sugar is actually toxic (Is sugar ‘toxic’?) and even addictive (Now sugar is ‘addictive’). Or at least that’s the story you hear from the popular press.

With anti-sugar sentiment at fever pitch, two Australian nutritionists had a radical thought: why not look at some scientific evidence?

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Why do children prefer sweet foods?

Posted on September 27, 2012 by Bill Shrapnel

All children like sweet foods. Maybe now we know why.

All humans appreciate sweetness in foods. However, this preference for sweetness is not constant throughout life; it’s age-dependent, being strong in children but relatively weak in adults. The transition occurs in late adolescence, in both sexes. This is not a western phenomenon – it is experienced in all races and cultures.

But why is it so? What purpose does the preference for sweetness in childhood serve? Is it a problem? And should nutritionists intervene to manage children’s preference for sweetness?

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Do monounsaturated fat-rich diets prevent diabetes?

Posted on September 19, 2012 by Bill Shrapnel

An important new dietary trial has produced challenging results. And there is more to come.

A decade ago two similar studies were undertaken in Finland and the United States to test whether type 2 diabetes could be prevented by diet and lifestyle. In both studies, overweight subjects with pre-diabetes were placed on low fat, weight reduction diets and exercise programs. Amazingly, the results of the two studies were exactly the same: the interventions lowered the incidence of diabetes by 58% over three years. The key drivers of the benefit were considered to be weight loss and increased physical activity.

One issue that these trials did not explore in any depth was the role of diet quality in diabetes prevention i.e. was the ‘low fat’ aspect of the diets relevant? The recent results of the PREDIMED trial provide some tantalising insights.

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Why traffic light labelling of foods won’t work

Posted on August 29, 2012 by Bill Shrapnel

The policy makers are desperate to do something about obesity but traffic light labelling would achieve nothing. The nutrition criteria at the heart of the concept are wrong.

Health authorities around the world have struggled to find effective ways of addressing the obesity epidemic. One recommended strategy is the introduction of traffic light labelling of food products to make it easier for the general public to choose healthier foods in the supermarket. It is argued that healthier food choices would not only tackle the obesity issue but could also address many other diet-related chronic diseases. Sounds good in theory but it simply won’t work. Continue reading →

Wholegrains, whole foods and health: where does the science end and the philosophy begin?

Posted on August 22, 2012 by Bill Shrapnel

When nutrition experts review the same data and come to different conclusions we have to ask why?

Nutrition experts review scientific evidence for different reasons. On the one hand a review might be conducted during the development of healthy eating advice for the general public – this has occurred recently in Australia during the preparation of the new Dietary Guidelines. In the United States and Canada, another reason for reviewing scientific evidence is to apply for a health claim – a government-sanctioned claim for use on food packaging. Such claims are a boon to marketing and are highly sought after. Whatever the motive for a scientific review on a particular topic, the results should be pretty much the same. Evidence is evidence. But it doesn’t always turn out that way.

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‘Is low fat milk unhealthy?’

Posted on August 8, 2012 by Bill Shrapnel

A current affairs program broadcast last week posed the question: ‘Is low fat milk unhealthy?’ And then followed up with ‘For more than two decades we’ve been encouraged to go low fat or even no fat when it comes to milk, but stunning new results may change all that.’ Really? What are these stunning new results?

Whenever new scientific findings are announced via current affairs programs on television my scepticism antennae start to twitch. It’s a safe assumption that a public relations firm has been engaged to push the story through to the general public. Let’s look at the science behind it.

The trigger for the program was a review published in the European Journal of Nutrition exploring possible links between the consumption of high fat dairy foods and risk for cardiovascular disease and obesity. This is one of a series of reviews of epidemiological evidence relating to dairy foods published over the last few years.

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Carbohydrate quality: a new model

Posted on July 24, 2012 by Bill Shrapnel

The long-held view that carbohydrate-rich foods are protective against heart disease, or at least benign, turns out to be wrong. Carbohydrate recommendations are too high but which carbohydrate-rich foods should be recommended in a healthy diet and which foods should be culled?

One of the most important findings from nutrition research in recent years was that carbohydrate confers similar risk for coronary heart disease to saturated fat. This turned 20 years of dietary advice on its head as it meant that the long-recommended low fat diet was not protective against heart disease. It followed that carbohydrate recommendations were too high and if lower intakes of carbohydrate were to be recommended, it would make sense to preference ‘good’ carbohydrate.

But what is good carbohydrate? Ask this question to a room full of nutritionists and the argument will go on for hours. Thirty years ago starch was considered good and sugars were bad, based on the assumption that starch was digested more slowly and raised blood glucose levels more gradually than sugars. However, studies of glycaemic index showed this assumption to be wrong. So should nutritionists forget about sugar and start recommending low GI foods? There are also arguments over whether ‘wholegrain’ or dietary fibre is the better measure of a good cereal food. In the United States, nutrition authorities have adopted nutrient density as an over-arching principle of their latest dietary guidelines. It would certainly make sense to favour nutrient-rich carbohydrate foods if total carbohydrate intake (or calories) was to be limited. So there are lots of options and opinions but no consensus on what represents good and bad carbohydrate.

Against this swirling background Professor Manny Noakes from CSIRO and I recently published a new model for assessing the nutritional quality of carbohydrate-rich foods.

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