Chapter 3 - Animal Products and Human Nutrition

Abstract

Total and per capita consumption of animal products (meat, milk, eggs, and fish) are increasing globally. This shift reflects improved living standards, consumer demand, and efficient production. It should be recognized that 765 million people still suffer from chronic undernourishment/hunger. Animal products have high contents of protein and fat, particularly saturated fat. Animal products provide a source of highly digestible protein and of high quality with good balance of amino acids particularly indispensable amino acids. In the USA, people with an omnivorous diet consume 65% of their protein intake and 26% of their energy from animal products. The Recommended Dietary Allowance for protein is 56 g day−1 for men and 46 g day−1 for women. Meat, fish, eggs, and dairy products are a valuable source of minerals including calcium, zinc, and iron together with vitamins, such as vitamin B12. Animal products are predominantly low in carbohydrates except dairy products, which contain the disaccharide, lactose. The intestinal enzyme, lactase, is essential for lactose digestion. The expression of lactase decreases in most children. However, the enzyme persists in some people depending on their genetics and they can readily digest dairy products. In contrast, when lactase declines there is lactose intolerance. Animal products, such as liver and eggs are important sources of essential fatty acids (alpha-linolenic acid, linoleic acid, eicosapentaenoic acid, and docosahexaenoic acid; these being critical to the development of the brain and nervous system. Nutrient deficiencies, especially of animal product-rich nutrients, are a major problem globally. Protein malnutrition continues to be a major problem globally. Protein–energy deficiency results in stunting and insufficient weight in over 175 million children. Deficiencies in micronutrients result in 50% of deaths, directly and indirectly, to children and infants less than 5 years old globally. Iron deficiency impacts 30% of the world’s population. Vitamin B12 deficiency is widespread globally being found, for instance, in 40% of children and adults in Latin America, 70% of children in Kenya, and 80% of children in India and in the elderly and vegans in Western countries. Processed red meat and probably nonprocessed red meat have negative effects on health and mortality. Cholesterol is no longer viewed as a nutrient of concern for overconsumption. The safety and sustainability of animal products and ongoing use of animal products are discussed.