Cooking and grinding reduces the cost of meat digestion.
Level 5 - mechanism / opinion, no new human data
Animal physiological laboratory experiment (non-human model).
PubMed 17827047 · doi:10.1016/j.cbpa.2007.08.014
What was done
Burmese pythons (Python molurus) were fed one of four experimental beef diets weighing 25% of body mass: intact raw beef, intact cooked beef, ground raw beef, or ground cooked beef. Researchers measured pre-feeding and postprandial oxygen consumption rates up to 14 days following feeding to calculate specific dynamic action (SDA), representing the metabolic cost of digestion, absorption, and assimilation.
What was found
Postprandial peak oxygen consumption, peak scope, and total SDA differed significantly among treatments. Cooking decreased SDA by 12.7%, grinding decreased SDA by 12.4%, and combined cooking and grinding decreased SDA additively by 23.4% compared to intact raw meat.
Why it matters
Provides experimental evidence that thermal and mechanical processing reduces the metabolic cost of digestion, supporting the hypothesis that cooking increased net energy gain during human evolution.
Limits
The abstract does not state the number of animals used (n). Findings are from an ectothermic reptile model (Burmese python) consuming large infrequent meals, which limits direct extrapolation to human digestion.
Cited by
- supports Stephen Secor's research on boa constrictors showed that ground rats require significantly less diet-induced thermogenesis to digest than whole rats.