Tigers are carnivores and literally consume everything that is motile but most of their prey in India consists of deer, wild boar, bison or gaur, and antelope. They are voracious eaters and one fully grown male Tiger weighing around 250 plus kg can consume 30 kg of meat at one go.  

The big cat makes a kill mostly by ambush or a small chase. The death is due to fracture in the cervical region by impact as the tiger pounces and by the rupture of blood vessels in the neck by sharp canines. The big cats can hold the neck region for quite some time till the prey dies. They can hold the massive bison as well this way which is an amazing feat considering that the bull weighs over a ton in the wild. In the wild, there is no time to chew hence they clean the Animal of fur and begin eating by gulping pieces of meat.  Once the meal is over they must drink and hence they approach a waterbody or a waterhole sit down on limbs and gulp water. They consume a lot of water at one go.  

As a routine, the predators drink once in the early morning and then at dusk and this is enough. This routine is maintained even during the hot summer. The animals with fur cannot perspire and they resort to expelling heated air from the body consistently. In summer you will find the tiger panting profusely in order to control the body temperature. Another way is to wallow or bathe in the muddy pools or waterholes during the summer.   I have seen big cats literally rolling in a Pool to cool themselves. In the summers tiger bathing in a pool or waterhole is a matter of routine. This is when they drink to satiate thirst as well.  A pool may be frequented by a number of predators and sometimes there can be a conflict. Guides and naturalists keep an eye on water sources to search or track wild animals in the National Parks or reserves. 

Unlike other wild animals especially the prey species these carnivores need not be cautious while approaching as waterbody. They walk at ease to approach a waterbody and relax for quite a time in the safety of the reserves. 

Sometimes one can see the whole family submerged in water male, female, and cubs all together to beat the heat. I have often seen male tigers drinking in water or while sitting at the edge.

These predators are purely meat eaters or carnivores but on rare occasions, I have seen them eating grass or licking sand for minerals. This is nature's way of aiding digestion and consuming healthy nutrients like vitamins and minerals not available in animal meat.