Index

2007-09-30

Vegan, Vegetarian, Omnivore, and Carnivore

Vegans follow a philosophy of eating only vegetable products, whereas vegetarians allow themselves to eat some animal products such as eggs and milk. Vegans usually avoid animal products for ethical, health or environmental reasons, whereas vegetarians who consume eggs and milk point out that their dietary choices do not harm other living beings. Omnivores will eat both vegetable and meat products, and carnivores eat only other animals.

Humans have evolved eating a varied diet and this has resulted in evolutionary adaptations that set certain limitations on what we should eat to be healthy. Unlike other mammals, humans do not have the capacity for making Vitamin C and this requires regular consumption of fruits and vegetables to avoid scurvy. Similarly, the human body needs to have Vitamin B12 and essential omega-3 and omega-6 fatty acids that can be satisfied by eating fish. People who are strictly vegan usually develop Vitamin B12 deficiencies unless they consume fortified products. Vitamin B12 deficiency can result in anemia and nervous system damage. Low levels of Vitamin B12 increase the risk of heart disease or pregnancy complications.

Cats are strict carnivores whose nutritional needs must be the met by eating meat or animal-based protein. Insufficient dietary protein results in the loss of skeletal muscle tissue. Like humans, cats convert carbohydrates that are not used for energy into body fat. A diet should have the right proportion of macronutrients to supply all the essential nutrients with a low enough level of calories to avoid obesity.

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