While total egg consumption and the uptake of eggs/person will continue to grow long term virtually everywhere, in developing countries the gains will be via purchases of shell eggs. In contrast, the rise for many developed economies will reflect an increase in eggs eaten in egg products,which in some instances will be at the expense of the uptake in shell. Indeed, as can be seen by reference to the table, in the USA, the proportion of eggs broken for further processing and consumed in product forms now exceeds 30% of total production, and some industry observers consider that this figure will rise to 50% by 2020.

In developed nations, a transition has taken place in the ways in which eggs are perceived as part of the human diet in the past decade or so. It is now possible to show that including eggs in a diet will lower the risk of heart disease, breast and colon cancers, age-related eye diseases, muscle loss in the elderly and help in tackling the obesity issue, which is now evident in so many countries. However, whether egg marketers capitalise on the many attributes inherent in eggs that would give consumption a boost remains to be seen.

Egg consumption per person ranges widely between countries. In those surveyed by the International Egg Commission (IEC), it varied from a low of 47 in India to a high of 345 in Mexico (see table), where more eggs are eaten per person each year than in any other country in the world.

To a great extent, movements in the levels of consumption actually reflect changes in available supplies. After a profitable year, producers tend to expand output and, as long as this increase exceeds population growth, the level of consumption per person will rise. On the other hand, industry output will contract after a period of low profits or even losses and, on the assumption that imports do not increase, this will mean that total supplies decline, as will the number of eggs eaten/person.

Few countries actually directly measure egg consumption, the published figures being derived from a number of calculations, all of which are surrounded by question marks.

While questions are posed by virtually all the figures relating to the world's poultry industry – as most include a degree of estimation – by far the greatest margins of error relate to those concerning consumption and, in particular, egg consumption.

This is because:

1. the measurement of the number of layers in a country can be imprecise, as can the assessment of the number of eggs laid
2. the egg production figures usually include hatching eggs with table eggs
3. although the percentages differ by country, often a relatively high proportion of output comes from so-called non-commercial or backyard flocks, this figure being estimated
4. eggs are highly susceptible to damage in transit from the farms to the consumers' table giving rise to what may be not inconsiderable losses in distribution
5. a further problem emerges when, as in many instances, the consumption data is expressed as a quantity eaten/person, not only because of estimated changes in the human population, but also because the average egg weight differs between countries.

Hence, any series of data is best used as a guide to trends rather than absolute levels.

Sometimes 'consumption' is confused with 'demand'. That the number of eggs eaten per person in one year has declined when compared with the previous year, does not mean that the demand for eggs has fallen. This can only be ascertained when account is taken of changes in the prices which the consumers paid for the eggs.

Sadly, in these days of heavy advertising of products, the egg industry spends a relatively insignificant amount of money on promotion. Even among developed economies the sums spent on generic promotion of eggs does not even represent 1% of the retail sales value of the eggs.

In developed economies, changes in real incomes have little or no impact on egg purchases. In contrast, in developing countries improvements in real disposable incomes play a significant role on the number of eggs purchased. Indeed, the two key factors impacting on the demand for eggs are population and real income growth. Other factors, such as changing life styles, egg production systems and health scares have a role to play in influencing demand but these are mainly evident in developed economies.

In the developing countries, people are much less concerned about whether layers are kept in cages or not, or that eating eggs can have a negative impact on the blood cholesterol levels of a small proportion of the population.

An appraisal by the International Egg Commission's Statistical Analyst, Professor Hans-Wilhelm Windhorst, indicates that between 2005 and 2015, the global human population will likely expand from around 6.5 billion to 7.3 billion – an increase of 770 million or 12%. Almost 60% of this increase will take place in Asia. Indeed, this region, combined with the anticipated growth in Africa will account for 76% of the global population in 2015, and a massive 87% of the increase over this period.

Professor Windhorst has also shown that in most Asian countries per capita and total egg consumption will increase because of an expanding middle class with growing buying power. "By 2020, if not earlier, in China and India a middle class of about 700 to 750 million people with a buying power comparable to that in Europe today, will have completely changed the market situation for food in East and South Central Asia," he observes.

As indicated earlier, the news coverage given to the outbreaks of Highly Pathogenic Avian Influenza (HPAI), has not had as adverse impact on the demand for eggs as for poultry meat. In contrast the publicity, much of it incorrect, given to eggs and cholesterol has hit egg consumption, particularly in developed economies. This is a battle that is being won by egg industries, but only slowly, despite the fact that it has been proved that eating eggs has no impact on the levels of blood cholesterol for most people.