Two years ago on April 15th I took a solo hike up Snake Den Ridge Trail in the Smokies. I was carrying a 50 pound pack, not in good enough shape. It began to snow as I started about 8a.m. Because of my age, lack of fitness, and pack I proceeded extremely slowly. Because of the snow and 28 degree weather I did not want to stop as there was no place to sit on the narrow rocky trail. I had a good breakfast before starting but did not eat during the day. My feet were wet from crossing streams.
Long story, short, I came down with hypothermia (?) about 4pm. I knew enough to realize I was in trouble. I stopped, pitched my tent, heated water, ate, drank, and survived.
Moral? Lack of energy provided by food contributes to Hypothermia very quickly.