Benefits of Food from Animals

1. They are rich in vitamins and minerals.
2. Eating meat strengthens the bones and immune system.
3. Young children should consume enough milk to enrich the calcium in the body.
4. Drinking milk makes the bones and teeth stronger.Benefits of Food from Animal.Meat: it's what's for dinner.
   Meat consumption has a long history in human evolution, likely going back to the earliest known human-like ancestor living 5–7 mya (1–3). The presence of primitive stone tools beginning at ∼2.5 mya in eastern Africa indicates that early humans likely had the capability of cutting and processing meat from animals. For example, cutmarks made from stone tools on the bones of animal prey found in Kenya and Ethiopia indicate meat consumption (4,5). Before 2.5 mya, the archaeological record of meat consumption is nonexistent, but the commonality of hunting and meat eating by our nearest common ancestor, the chimpanzee, suggests that meat eating has an ancient history, extending before the appearance of a human-like primate some 6–8 mya (6).Meat: it's what's for dinner.
   ABSTRACT:
   Animal source foods (ASF) have always been a constituent of human diets. Their pattern of use, however, changed in dramatic ways over the course of human evolution. Before 2 million years ago (mya), meat in particular was acquired opportunistically via hunting of small or young animals and scavenging of animals killed by other species. At some point after that time, humans began to hunt cooperatively, making possible the acquisition of meat from large game. The marked increase in human heights between 2.0 and 1.7 mya may be linked to more efficient means of acquiring meat, namely through hunting.
   The final pattern of meat (and other ASF) use before the modern era is associated with the shift from hunting and gathering beginning ∼10,000 y ago. This fundamental dietary change resulted in a narrowing of diet, reduced consumption of meat and increased focus on domesticated grains. The study of archaeological human remains from around the world reveals that this period in human dietary history saw a decline in health, including increased evidence of morbidity (poorer dental health, increased occlusal abnormalities, increased iron deficiency anemia, increased infection and bone loss). Human populations living in developing and developed settings today rely on meats with lipid compositions that when eaten in excess promote cardiovascular disease.
   How Animal Sourced Foods Contribute to a Healthy Diet
   ASF such as milk, meat, eggs and fish contribute to a balanced human diet, especially in LMICs where meals are largely starch-based and lacking diversity. ASF contribute towards food and nutrition security in terms of caloric (energy) intake but also in terms of nutrients that are essential for the healthy functioning of the human body.

Dietary energy is fuel for the human body and needed to keep it alive and warm. An adult woman with a low level of physical activity (e.g. doing administrative work in an office and spending most of her free-time sitting) requires about 7000 Kilojoules (kJ) per day to maintain her body weight, in men it is about 25% higher. These basic energy supplies can be obtained from carbohydrates, proteins and fat in the diet. One gram of carbohydrates (sugars and fibres), protein or fat contain 16, 17 and 37 kJ energy, respectively. 
ASF are considered energy-dense foods mainly due to their higher fat contents. That is one reason why they are frowned upon by the figure-focused but comparatively sedentary population in HICs. However, in populations with chronic caloric undersupply, animal fat can help increasing the number of calories in the dish. Plant-based food is rich in energy, too, although a lot of may be lost during cooking.

Other than energy, ASF also contain a lot of micronutrients. Moreover, those that they contain are also highly bioavailable to humans, which means that humans can utilize them very easily, some of them even more efficiently than from plants. For instance, ASF contain proteins of high biological value because the profile of the amino acids (the building stones of proteins) are very well-matched to the human body's requirements; they contain all amino acids that humans need and even contain some that plants do not. 
Tryptophan is an amino acid that is converted into niacin (vitamin B3) which the body needs to function properly: It is a precursor of the neurotransmitter serotonin (for well-being and happiness) and the hormone melatonin (for regulating sleep and wakefulness). Another example is Vitamin B12 (cobalamin), which is helping to build and maintain the nervous system and red blood cells. Iron, too, is an important nutrient found in ASF.
Iron deficiency is thought to be the most common cause of anaemia,a condition found most commonly in sub-Saharan Africa (WHO, 2015).
These nutrients and a few others cannot be synthesized by the human body itself, so they have to be obtained from the diet, which is why they are referred to as “essential”. Tryptophan can be found in some vegetables and staples such as rice but communities with a staple diet that is maize-based may have some deficiencies that can result in disease. Vitamin B12 is exclusively found in animal products, especially liver, but never in plants.

In the case of iron, it can be found in both ASF and plant food. There are two types of iron in food: first, haem-iron which is only found in meat, poultry, fish and seafood, and very easily absorbed in the human intestine; and second, non-haem iron which is found in plant-based foods, such as vegetables, cereals, legumes and pulses. However, it is not easily absorbed by the human body. Moreover, much smaller amounts of animal sourced foods, especially liver, need to be eaten to obtain the required amounts. 
This is especially helpful in improving children's diets as they cannot consume big volumes of foods, and small amounts of animal sourced foods could already significantly improve a crop-based diet. In addition to that, the presence of haem-iron in one dish (e.g. in pig liver) facilitates better absorption of non-haem iron (e.g. cabbage or spinach) in the meal.