It is a world-wide experience that economic growth creates an increasing demand for food of animal origin, and, once a certain income level is reached, the demand for food of vegetable origin shrinks. Therefore, the proportion of animal products in the human diet is almost an indicator of the income level achieved by certain population groups or whole countries (excluding vegetarian societies on the one hand and pastoral societies on the other). FAO's provisional food balance sheets (FAO, 1977) indicate that, in most low income countries, animal products contribute less than 10% to total energy intake, whereas in high income countries they contribute almost 50%