WEDNESDAY, Nov. 9 (HealthDay News) -- Cooked meat provides more energy than raw meat and may have helped drive human evolution, according to a new study.
The finding that cooking increases the energy we derive from meat also raises questions about the way modern humans eat, said Rachel Carmody, a student in the department of human evolutionary biology at Harvard University.
In her study, she fed two groups of mice different diets of meat or sweet potatoes over 40 days. The food was prepared four ways: raw and whole; raw and pounded; cooked and whole; and cooked and pounded.
Changes in each mouse's body mass index were tracked, along with how often they used an exercise wheel. The results clearly showed that cooked meat provided more energy to the mice than raw meat, Carmody said.
The study appears in the Proceedings of the National Academy of Sciences.
"The results of this paper are equally relevant to human evolution and to the way we think about food today," Carmody said in a Harvard news release.
"It is astonishing that we don't understand the fundamental properties of the food we eat. All the effort we put into cooking food and presenting it -- mashing it up, or cutting it, or slicing or pounding it -- we don't understand what effect that has on the energy we extract from food, and energy is the primary reason we eat in the first place," she noted.
Early humans were eating raw meat as early as 2.5 million years ago but they underwent a sudden change about 1.9 million years ago. Their bodies became larger, the size and complexity of the brain increased, and adaptations for long-distance running appeared.
Some theories suggest that increased meat in the diet produced these evolutionary advances, but Carmody's findings point to another reason -- cooking meat provided early humans with more energy.
The Smithsonian has more about human evolution.
-- Robert Preidt
SOURCE: Harvard University, news release, Nov. 7, 2011
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