They don’t have sources, because the available scientific evidence strongly suggests that they’re wrong. The classic study on this used pythons to measure the

They don’t have sources, because the available scientific evidence strongly suggests that they’re wrong. The classic study on this used pythons to measure the energy cost of digestion. Cooked meat was significantly cheaper to digest than uncooked meat: https://www.sciencedirect.com/science/article/pii/S1095643307015632 https://www.sciencedirect.com/science/article/pii/S109564330... Another study on mice measured metabolic changes following a diet of cooked vs uncooked food. Again, mice did better with cooked meat than with uncooked (they lost weight on both as a pure meat diet is not a perfect food or mice, or humans for that matter): https://www.pnas.org/content/108/48/19199 https://www.pnas.org/content/108/48/19199