Found a really interesting article on nutrition!
Death of the calorie
Some notable quotes:
"Susan Roberts, a nutritionist at Tufts University in Boston, has found that labels on American packaged foods miss their true calorie counts by an average of 8%. American government regulations allow such labels to understate calories by up to 20% (to ensure that consumers are not short-changed in terms of how much nutrition they receive). The information on some processed frozen foods misstates their calorific content by as much as 70%."
"That isn’t the only problem. Calorie counts are based on how much heat a foodstuff gives off when it burns in an oven. But the human body is far more complex than an oven. When food is burned in a laboratory it surrenders its calories within seconds. By contrast, the real-life journey from dinner plate to toilet bowl takes on average about a day, but can range from eight to 80 hours depending on the person. A calorie of carbohydrate and a calorie of protein both have the same amount of stored energy, so they perform identically in an oven. But put those calories into real bodies and they behave quite differently. And we are still learning new insights: American researchers discovered last year that, for more than a century, we’ve been exaggerating by about 20% the number of calories we absorb from almonds."
"Some people’s intestines are 50% longer than others: those with shorter ones absorb fewer calories, which means that they excrete more of the energy in food, putting on less weight."
"There’s a further weakness in the calorie-counting system: the amount of energy we absorb from food depends on how we prepare it. Chopping and grinding food essentially does part of the work of digestion, making more calories available to your body by ripping apart cell walls before you eat it. That effect is magnified when you add heat: cooking increases the proportion of food digested in the stomach and small intestine, from 50% to 95%. The digestible calories in beef rises by 15% on cooking, and in sweet potato some 40% (the exact change depends on whether it is boiled, roasted or microwaved). So significant is this impact that Richard Wrangham, a primatologist at Harvard University, reckons that cooking was necessary for human evolution."
"The difficulty in counting accurately doesn’t stop there. The calorie load of carbohydrate-heavy items such as rice, pasta, bread and potatoes can be slashed simply by cooking, chilling and reheating them. As starch molecules cool they form new structures that are harder to digest. You absorb fewer calories eating toast that has been left to go cold, or leftover spaghetti, than if they were freshly made. Scientists in Sri Lanka discovered in 2015 that they could more than halve the calories potentially absorbed from rice by adding coconut oil during cooking and then cooling the rice. This made the starch less digestible so the body may take on fewer calories (they have yet to test on human beings the precise effects of rice cooked in this way). That’s a bad thing if you’re malnourished, but a boon if you’re trying to lose weight."
