2nd of all, of course it would be possible, especially if u allow the use of animals that die of natural causes, u can still get plenty of leather, bone, sinew, etc…

Changes to diet.
Because of the indigestible components of plants such as raw cellulose and starch, certain parts of the plant such as stems, mature leaves, enlarged roots, and tubers would not have been part of the hominid diet prior to the advent of fire. Instead, the consumption of plants would be limited to parts that were made of simpler sugars and carbohydrates such as seeds, flowers, and fleshy fruits. The incorporation of toxins into the seeds and similar carbohydrate sources also affected the diet, as cyanogenic glycosides such as those found in linseed, cassava, and manioc are made non-toxic through cooking. The teeth of H. erectus and the wear on the teeth reflect the consumption of foods such as tough meats and crisp root vegetables.

Early Humans and the Advantages of Eating Meat.
The cooking of meat, as evident from burned and blackened mammal bones, makes the meats easier to eat and easier to attain the nutrition from proteins by making the meat itself easier to digest. The amount of energy needed to digest cooked meat is less than raw meat, and cooking gelatinizes collagen and other connective tissues as well, “opens up tightly woven carbohydrate molecules for easier absorption.” Cooking also kills parasites and food poisoning bacteria.

scientific evidence all indicates that we are omnivores, i.e., we can survive on a wide variety of plant and animal foods. It also used to be believed that the great apes were all frugivores (fruit-eaters), but recent reseach shows that chimpanzees at least will attack and kill small animals and will eat carrion if they find it. The chimpanzee is thought to be our closest animal relative.

The extreme opposite concept, however, that of Man the Great Hunter, also seems to be untrue. In his book The Rise and Fall of the Third Chimpanzee, Jared Diamond describes how he was invited on a hunt by a tribe in New Guinea who had retained Stone Age technology and habits of thought in the 20th century. The day’s total bag was two baby birds, a few frogs, and a lot of mushrooms. Although the men of the tribe frequently boasted of the large animals they had killed, when pressed for details, they admitted that large animals were killed only a few times in a hunter’s career. These peoples’ stone tools were far more advanced than the stone tools found on prehistoric sites, so Professor Diamond thinks it unlikely that prehistoric hunters could have enjoyed a much higher success rate than present day hunter-gatherer tribes. It seems more likely that early humans ate carrion, small prey like baby birds, and a lot of plant foods.

He cites a notable exception to this rule. The first humans to colonise a previously unoccupied island or continent, e.g., Madagascar, New Zealand, and America, found animals so tame that they didn’t run away from hunters. In these instances, something like 80 percent of the large birds and mammal species of such an area were exterminated in a relatively short time.

The underlying issue is one of morality. Moral beliefs are subjective– modern conveniences give us the luxury to say that exploiting animals is wrong, but what gives us the right to say that everyone worldwide, in every culture and time period, should have the same belief? Who are we to say that its OK for a hunter-gatherer to pick fruit from a tree, but wrong for him to take honey from a hive? Cultures and lifeways are based on adapting to environments, using what is in the environment to survive. The idea that animals are off-limits is a wholly modern notion. Even looking at the history of Hindus and other groups that consider animals sacred or are vegetarian for religious reasons, I don’t know of any evidence that anyone practiced or advocated veganism before modern times. It was often impossible, always impractical, and would have made no sense to people’s worldview.

Jared Diamond says though that in his experience (he has spent many years of his life with the tribes of Papua New Guinea) with ‘primitive’ peoples who we usually see as great hunters, and we think of primitive man in general as being great hunters, when questioned, their diet consists of mostly vegetation and some small animals. The great hunter bringing down large mammals is mostly a myth, he says.