Gorillas are principally herbivores who at least feed on a part of a green plant. Mountain gorillas spend much of their day roaming the ground in search of one or more out of the 38 plant species which they love to eat. These include celery, thistles, gallium, bamboo shoots and nettles but sometimes when the temperatures become too hot or when they fail to find a desirable feeding spot, they may end up feeding on barks of trees, dead wood and invertebrates.

The lowland gorilla on the other hand have a diet that mainly consists of fruits which they get from at least 100 species of trees and therefore end up climbing three more than the mountain gorillas in search of these colorful and sweet fruits.

Male gorillas consume more than their female colleagues; perhaps an explanation for the difference in size. Males eat up to 30 kilograms (66 pounds) of food day while the daily food consumption of an adult female gorilla is 18 kilograms (40 pounds).

Eating speeds vary among gorillas; normally basing on their age. The youthful gorillas, like the juveniles and blackbacks tend to eat their food faster that the infants and the aging gorillas. At the age of 35 years gorillas begin to develop weaknesses in their jaws while some of them begin to lose their teeth and this makes it harder for them to chew through their food.