Tuesday, September 30, 2008

Dietary guidelines and the obesity epidemic

In a recent issue of the American Journal of Preventive Medicine (2008;34:234-240; http://www.ncbi.nlm.nih.gov/pubmed/18312812?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum) Paul Marantz, Elisabeth Bird and Michael Alderman from the Department of Epidemiology and Population Health of the Einstein College of Medicine, New York, published a paper in which they call for higher standards for dietary guidelines. Their paper argues that dietary guidelines are often based on indirect and sometimes weak evidence, that resulting guidelines may cause harm instead of health benefits, and that dietary guidelines may better be avoided if not based on adequate evidence. They use the fat reduction guideline as an example. In the 1980s and 90s dietary recommendations in most countries included recommendations to reduce dietary fat intake to less than 30 or 35 percent of total energy intake. The authors argue that this recommendation was not based on firm evidence (i.e. total fat is not an issue, type of fat is more important) and that the recommendation has issued changes in peoples diets and in food production and innovation towards less fat, but also towards more sugar and other carbohydrates, leading to higher calorie intakes, and thus possibly contributing to the obesity epidemic. A comment on their paper by Steven Woolf and Marion Nestle was published in the same issue (http://www.ncbi.nlm.nih.gov/pubmed/18312816?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DiscoveryPanel.Pubmed_RVAbstractPlus).

Local produce and the 100 mile diet

'Normal' farming, with the use of loads of fertilizer, long transport distances from farms to food industry to retail to consumers causes lots of wasted energy and leaves a huge carbon foodprint. I reported here earlier on the 100 mile diet, initiated by Alisa Smith and J.B. MacKinnon, i.e. "local eating for global change" (http://100milediet.org/). The 100 mile diet may be much easier for more people when 'skycraper framing' is applied: vertical farming right in the middle of urban areas.

Vertical framing is a possible means to grow grains, fruits and vegetables and fruits, raise poultry and pork, use their waste as fertilizer, and use city waste water for irrigation. A vertical farm could potentially reduce the fossil-fuel use and emissions associated with farming. Year round growth and harvesting could be possible, and consumers could get real fresh, organic produce near their city homes.

Vertical or skycraper farming (http://www.sciam.com/article.cfm?id=growing-vertical-skyscraper-farming or http://en.wikipedia.org/wiki/Vertical_farming), i.e. a multi-storey building with integrated crop and animal farming, is one of the ideas for Earth 3.0 (http://www.sciam.com/article.cfm?id=introducing-earth-3-point-0), as described in the September 2008 issue of Scientific American. In these Earth 3.0 terms, Earth 1.0 was the earth that existed for billions of years untill well into the 18th century. Earth 2.0 came into existence with the industrial revolution leading to enourmous tehnological achievements and health benefits resulting in longlevity and prosperity for at least the richer part of the world.

Earth 3.0 should combine the prosperity of Earth 2.0 for all with the sustainability of Earth 1.0. With a large majority of the world population living in cities within the next few decades, vertical farming may contribute to a more sustainable and healthy food producion chain.

The technology for vertical farming does exist and the idea has received quite a bit of media attention lately (see http://www.verticalfarm.com/Default.aspx).