Man is an omnivore, that is, he can feed on both plants and animals. Thus, a man can be a primary consumer when he consumes plant products such as cereals, fruits and vegetables and he can be a secondary consumer when he consumes herbivores such as goat and sheep (in the form of their meat). Thus, a man can be placed at the second as well as the third trophic level of the food chain. Man cannot be a producer because he cannot convert energy from sunlight, which is chemical energy conversion to food. Only plants have that function to prepare food through photosynthesis. Therefore man can only consume food and is known as a consumer.