Over the past 50 years, agricultural activities has been significantly increases to keep up with the growing population of the world. A regular meat diet of human mostly consists of beef, pork, lamb and chicken. Meat is recognised to be a significant part of the human diet because it provides good source of nutrients, including great amount of proteins and micronutrients such as iron, vitamin B12 etc. However, meat intake should be restricted as research shown that meat, especially processed meat, are a risk factor of cancer and cardiovascular disease.
Meat are identified as the richest source of proteins. Proteins, made from amino acids is an essential component to muscles building in human. However, as the human body can only produce 60% of the amino acids compulsory for protein synthesis, the missing 40% has to come from external diet (de Castro Cardoso Pereira et.al, 2013). Meat is the ideal source as it consist of all the essential amino acids. However, studies found that these amino acids could also be obtained by combining legumes and wheat gluten in diet. By substituting meat with other protein food sources, such as fish, nuts and low-fat dairy products in diet have also concluded to significantly lower the risk of mortality (Harvard, 2014).
Iron is a vital component in the human body. It is known to present in a wide range of foods. In accordance to many findings, iron deficiency can results in impairment of biological functions, particularly in the growth and development of children. Heme-iron, which is only available in animal foods, is the better form of iron as it is high in bioavailability and can be easily absorbed by the human body (de Castro Cardoso Pereira et.al, 2013). Non-heme iron, which is an inverse to heme-iron, is mostly found in legumes, dairy products and cruciferous vegetables. Even though, legumes such as beans are the only source of iron in some population, this intake is not highly recommended, as some studies have shown that legumes may weaken iron absorption as they consist of non-digestible carbohydrates (de Castro Cardoso Pereira et.al, 2013).
Meat is a major dietary source of vitamin B12. Vitamin B12 intake required attention as low-intake of it is recognised to link with elevation of homocysteine, a risk factor for CVD and stroke. Several studies have shown that moderate meat consumption can lower the risk of B12 vitamin deficiency as well as proven that people with regular meat consumption tend to have lower homocysteine levels than vegetarian (McAfee et.al, 2010).
On the contrary, even though meat is a great source of various nutrients, meat is also high in bad, fatty contents such as saturated acids and trans-fatty acids. High level of these fats can elevate low-density lipoprotein (LDL) cholesterol, which is a risk factor of cardiovascular disease (Cattlemen, 2014). Studies have shown that consumers that consume high level of meat in their diet tend to have both higher total cholesterol level and LDL cholesterol than vegetarians and moderate or low meat intake consumers (McAfee et.al, 2010). A moderate serving of meat daily is recommended to be the portion of a palm-sized (Harvard, 2014).
As meat consumption is necessitate for good health, a meat demanding diet has recognised to use up many more natural resource that plants diet. In accordance to the Intergovernmental Panel on Climate Change (IPCC), agricultural activities is one of the underestimate factors which lead to global warming (Dunn, 2009). As the practice of industrial agriculture results in a great loss of land, deforestation is proceeded to make more land available for more agricultural production and suburban expansion.
Moreover, in order to fulfil the meat diet requirements of the growing populations, agricultural enterprises raises large numbers of animals, known as Concentrated Animal Feeding Operation