One of the demographic issues facing the planet in the next few decades is the world's expanding population. Many predictions have been made that the world's population will expand to somewhere in the order of ten billion people sometime this century. (Although other predictions have been made that our population peak will occur much earlier and at a much lower level that that...)  
One particularly urgent and seemingly intractable problem is how are we going to feed that population? Obviously ten billion people is many more people than currently live on the Earth (we're at about 7.1 billion people at the moment) and obviously we will need much more food to feed them all. However, when the problem of feeding the world is mooted, it is worth keeping the following points (and previous blogposts) in mind.
For a start, we produce much more food currently than is consumed -- what we struggle with is waste, storage, war and transportation of the food produced.
Second, technological advances in food production will probably continue to increase our ability to produce more food on poor quality soil and marginal land.
Third, food distribution is so uneven that even though 9 percent of the world's population is today underweight, there are more people overweight (13 percent) than underweight, an historically unprecedented situation.  
Leaving those caveats and notes to one side, it is obvious that if we want to feed a growing global population in anything like an equitable manner then the current Western lifestyle and eating habits will have to change.
As I've mentioned before on this blog, I have a lot of sympathy for calls that we should change our lifestyles to save the planet or to ensure that there are enough food resources in the world for everyone. I also think that the hysteria still surrounding the global population "explosion" is often an attempt to ensure that poor people somewhere else don't have any more children so that we in the more affluent areas of the world don't have to change our resource-rich lifestyle.
Focussing on the resource-requirements of people rather than the overall global numbers seems to make a lot of sense. After all, poor people living in sub-Saharan Africa or the slums of India are not going to require nearly as much food, pollute as much, or have as large a carbon footprint as some demography blogger in New Zealand does. 
But if we should change our lifestyle to accommodate an increased global population, how much change is necessary or possible? According to this article in the Tech Times, a team of researchers at the Institute of Social Ecology has modelled various scenarios and has concluded that we can produce enough food for the entire world until 2050 without cutting down any more trees -- if (and it's a big if) everyone stops eating meat, becomes vegan and eats organic products. As the article notes: 
"Animal agriculture is the leading cause of deforestation and habitat loss with 50 percent of the world's land dedicated to livestock growing." 
Now, turning the entire world vegan may not be realistic (for a start I’d need a lot more convincing) but this analysis does show the importance of not just how much we eat, but what we eat. Eating locally, eating more vegetables and less meat, and trying to conserve resources through our food choices are all practical ways we can help the world hold many more people. It is something we can all do every day that is fairly easy -- not a big, flashy world-wide policy initiative that the UN needs to take command of. All it takes is a bit of effort on all of our parts.
The small everyday sacrifice is not going to win you many plaudits, but it does make a difference. It’s something that we will discuss in our family to see how we can change our eating patterns. But I’m making it clear right now: I'm not giving up steak.