Sunday, Nov. 13, 2011
Do you like your steak rare or well done? A new study suggests we may be biologically adapted to skip rare, still-bloody beef in favour of thoroughly cooked meat.
Researchers have found meat provides more energy when it’s cooked, leading them to believe cooking played a key role in human evolution.
Lead author Rachel Carmody, a Ph.D. candidate in the department of human evolutionary biology at Harvard University, and a team of researchers compared how different preparations can affect the energy value of food. Using mice as test subjects, they found that the energy the rodents gained was greater when their food was cooked than when it was pounded and consumed raw.
The researchers fed separate groups of mice organic sweet potato or organic lean beef, prepared in various ways, over 40 days. They tracked the changes in the animals’ body mass to determine the energy they gained or lost on each diet.
Researchers hypothesize that changes to the structure of proteins caused by cooking may allow more to be absorbed and digested by the consumer, rather than by bacteria in the gut. Moreover, cooking makes muscle fibres easier to chew and increases the surface area of the meat that is exposed to gastric acids and enzymes. Cooking may also kill pathogens, like E. coli and salmonella, thus reducing the amount of energy the body expends for immune defence, the researchers suggested.
Their findings support the idea that traditional calorie-counting may be an inaccurate measure of the energy content of food. That also explains why raw-food diets generally lead to weight loss, Ms. Carmody said in an e-mail. However, such diets are not without risk; the researchers noted that previous studies found raw foodists experience high rates of chronic energy deficiency and reduced fertility. “This finding suggests that, in humans, the caloric gains conferred by cooking may be not merely advantageous but also necessary for normal biological function,” says the study, published in the Proceedings of the National Academy of Sciences.
So, the lesson I’m taking away from this? Isn’t some wacko, cultish Oprah-fad diet rumour. But if I didn’t go to the gym, or had no time jog, i’mma eat rawer. Whereas if I haven’t been eating enough on a single day, I’ll eat more well done veggies, meat etc. One should never eat the same things all the time, prepared the same way. That is insanity, and anality. Not to mention BORING. Our ancestors as they hunted and gathered, had a variety of things going through their systems, depending on what was hunted or how far the tiger was or what yummy bush berries they walked into. Variety and moderation is what, in my opinion, is healthy.