There is an ongoing debate on the contents of a draft report published by the National Health and Medical Research Council (NHMRC). The authors of this report are the Dietitians Association of Australia, with help from well known nutrition experts such as Dr Katherine Baghurst, Dr Peter Baghurst, Dr Lynne Cobiac and Dr Anthea Magarey.
The goal of the update is to translate the NHMRC Nutrient Reference Values for Australia and New Zealand Including Recommended Dietary Intakes (NRVs) into food consumption patterns that:
a) deliver the nutrient requirements for people of varying age/gender, activity levels and life-stages
b) are culturally acceptable, socially equitable and environmentally sustainable
c) reflect the current Australian food supply and food consumption patterns
d) provide some flexibility in food choice and;
e) promote health and wellbeing.
The approach used in the draft report was to use a mathematical model to optimise diets that theoretically contain all nutrient requirements for the various age, gender, and life stage groups analysed. The target was the least amount of energy (kilojoules, kJ), using a) to e) as constrains to the model.
Me being a modeller, I think this is a fabulous study that would be better placed as a research article, and not a draft for public consultation.
Why? Because the use of cultural, social and environmental constrains to model diets is highly controversial. In essence, it is like lumping concepts in fair trade, sustainable food chains, vegetarian/vegan/ carnivore/ religious beliefs into a simple set of mathematical limits. Can it be done? yes, but the richness of these topics is unavoidably simplified in a mathematical model, to the point of becoming a meaningless exercise.
For example, How do we assess some foods as more sustainable than others? True sustainable foods are not only judged in terms of their production footprint: it is also about distribution, manufacturing, marketing AND consumption. And distribution includes transport, storage, packaging and trading of foods. Therefore, it is not just a matter of saying that meat is more polluting than fruit and vegetables.
Likewise, social equity does not only refer to consumers, it also refers to producers. Unfortunately, the draft report uses a number of cliches about social and environmental factors to establish the constrains in their model.
The Australian published an article on July 21 2010, suggesting that the CSIRO and the National Heart Foundation were against the idea of including environmental drivers as an argument to limit the meat, fish and dairy intake in normal diets.
The Australian’s note refers to the submissions of both CSIRO and the Heart Foundation to the draft; I was not able to read those submissions myself, and neither the general public will be able to access them until the final report is released. Not surprisingly, the Australian Food and Grocery Council are also against the idea of using environmental drivers to suggest national diet guidelines.
Do I think that the model used in the NHMRC draft report was correct? No. I think it oversimplified very complex issues beyond what needed to be assumed in order to provide credible answers.
But I do think that there is a need to debate the effect of consumers’ food choices and environmental impacts. A good argument supporting this vision is given by Dr Rosemary Stanton in her Crikey article published yesterday. And I certainly think that we should acknowledge the social, political and environmental forces that make recommended national diet guidelines impossible to achieve for some parts of the population. I think this debate is extremely important.
A healthy diet is determined only by the effect of nutrients ingested in the human body. This ideal is what should set the vision of any dietary recommendations for a nation. Yet, when we choose the foods we eat, we are all subjected to social, cultural and environmental constrains. These constrained choices may undermine or benefit our health, our environment, our communities and our world. It is this effect that needs to be investigated. I am an adamant advocate of this holistic vision of food chains.