Both Mr Sng and Mr Jacobs think vegetarianism can alleviate the world food crisis by diverting grain used to breed farm animals to human consumption. I disagree.

According to a website by Oklahoma State University's Department of Animal Science, www.ansi.okstate.edu/breeds, it is true it is more efficient for humans to eat plant products directly rather than allow animals to convert them to human food. However, this inefficiency applies only to plant products humans can use.

In reality, over two-thirds of the feed given to animals consists of substances that are either undesirable or completely unsuitable for human consumption. Thus, by their ability to convert inedible plant materials to human food, animals, in fact, improve the quality of human diets rather than compete with humans for food.

Mr Sng also says vegetarianism could lessen environmental problems. This view is not well founded. Mr Ray Audette's book Neander-Thin, published in 2002, expresses the view that mono-culture agriculture not only depletes both soil and water sources, but also produces environmental damage by altering the delicate balance of natural ecosystems.

For instance, if people stopped breeding livestock for food, there would not be enough natural fertiliser to replenish soil for crops. We would then require the heavy use of artificial fertilisers, one tonne of which requires 10 tonnes of crude oil to produce.

Economically speaking, if a large number of people switched to vegetarianism, the global demand for grain would fall, resulting in a supply glut.

The root cause of starvation in the world is poverty rather than lack of supply. Vegetarianism would not only be an ineffective solution to world hunger, but would also compound the problem, economically and environmentally.

Ng E-Jay