Well, if we go by wikipedia, we can get several different versions:
"The Wendigo is part of the traditional belief systems of various Algonquian-speaking tribes in the northern United States and Canada, most notably the Ojibwe and Saulteaux, the Cree, the Naskapi and the Innu people.[4] Though descriptions varied somewhat, common to all these cultures was the conception of Wendigos as malevolent, cannibalistic, supernatural beings (manitous) of great spiritual power.[5] They were strongly associated with the Winter, the North, and coldness, as well as with famine and starvation.[6] Basil Johnston, an Ojibwe teacher and scholar from Ontario, gives one description of how Wendigos were viewed:[7]
“ The Weendigo was gaunt to the point of emaciation, its desiccated skin pulled tautly over its bones. With its bones pushing out against its skin, its complexion the ash gray of death, and its eyes pushed back deep into their sockets, the Weendigo looked like a gaunt skeleton recently disinterred from the grave. What lips it had were tattered and bloody [....] Unclean and suffering from suppurations of the flesh, the Weendigo gave off a strange and eerie odor of decay and decomposition, of death and corruption. ”
Well, dunno what to do with Winter theme thing except maybe be listed as being associated with them in legends. That does give nice description to them though... Hmm..
"At the same time, Wendigos were embodiments of gluttony, greed, and excess: never satisfied after killing and consuming one person, they were constantly searching for new victims. In some traditions, humans who became overpowered by greed could turn into Wendigos; the Wendigo myth thus served as a method of encouraging cooperation and moderation.[8]
Among the Ojibwe, Eastern Cree, Westmain Swampy Cree, Naskapi, and Innu, Wendigos were said to be giants, many times larger than human beings (a characteristic absent from the Wendigo myth in the other Algonquian cultures).[9] Whenever a Wendigo ate another person, it would grow in proportion to the meal it had just eaten, so that it could never be full.[10] Wendigos were therefore simultaneously constantly gorging themselves and emaciated from starvation."
Well, this could be interesting. A monster that grows in size more it eats.
Also, where does it say that? .-. It says that you become one by being possessed by cannibalistic spirit or becoming cannibalistic spirit yourself...