Monday, April 4, 2011
This post has a few graphs of very broad trends in food consumption around the world. All data come from the FAO (FAOSTAT Food Supply section) and run from 1961 to 2007. First up, above is the trend in total food supply in kCal/day/person for the world's largest areas (sorry Oceania). You can see that all areas have had steadily growing food supply in broad brush strokes. There are places in Africa where people are starving, but still, the average African eats about 25% more calories than his or her grandparents 40 years ago.
There have been some setbacks - for example, European consumption fell in the early 1990s when the collapse of the communist world caused a sharp reduction in food production in Eastern Europe, pulling down the European average. North American food supply peaked in 2005 and then fell slightly to 2007. I would guess this is due to the food/oil price spike at that time, but since North America had a different response than the rest of the world, it may also have something to do with those of us in North America just starting to reach practical limits to how much food we can stuff into our bloated faces.
So this is further context to recent food price spikes. Not only have farm prices been falling for decades previously, but the world has been getting better and better fed (at least as measured by quantity). Thus there is significant scope for a lot of us to eat less (not that we will do so willingly, but if forced, we aren't going to starve). Of course, there are many individuals for whom this is not true, and sudden changes will always cause much commotion.
This is also context for considering possible climate disruption to global agriculture going forward. Civilization currently has large unused reserves on both the supply side (agricultural investments not made because of low prices), and on the demand side (food consumed by people eating more than they really need). Thus, the real issues will be the social/political response to higher food prices (as we've seen in the Middle East lately), rather than any absolute shortage. People are creatures of habit, and the more their habits are disrupted by factors external to themselves, the more angry they get, which can translate into a force for political change.
Looking at the major macronutrients, here's an estimate of the fraction of calories coming from fat (obtainted by multiplying the FAO figures for grams of fat by 9 kCal/g):
You can see that not only are we all eating more and more, but we are all also getting more and more fat from our diets. Most strikingly, the average Asian is eating almost twice the fat percentage of forty years ago.
The North American line is interesting. I'm almost inclined to wonder whether the downswing from 1985 to the late 1990s reflected conscious efforts to be "low-fat", whereas the upswing after that represents the success of "low-carb" diets. I could be wrong, but I suspect there's no composition of nutrients that will allow people to eat as much food as North Americans eat, while driving everywhere, and still be healthy.
Finally, here is the fraction of calories coming from protein (again figured at 4 kCal/g).
I found this rather surprising. North American protein consumption is declining as a fraction of the diet (not in absolute terms), and most places are pretty flat. There also isn't nearly as much variation as I would have expected across the world. For example, I expected to see Asians eating a much lower protein diet than Americans forty years ago, and rapidly rising, but it's not so. Their protein fraction has only fluctuated a couple of percentage points the entire time.