Submission + - Why the calorie is broken (arstechnica.com)
An anonymous reader writes: Nutrition is a subject for which everybody should understand the basics. Unfortunately, this is hard. Not only is there a ton of conflicting research about how to properly fuel your body, there's a multi-billion-dollar industry with financial incentive to muddy the waters. Further, one of the most basic aspects of how we evaluate food — the calorie — is an incredibly imprecise concept. "Wilbur Atwater, a Department of Agriculture scientist, began by measuring the calories contained in more than 4,000 foods. Then he fed those foods to volunteers and collected their faeces, which he incinerated in a bomb calorimeter. After subtracting the energy measured in the faeces from that in the food, he arrived at the Atwater values, numbers that represent the available energy in each gram of protein, carbohydrate and fat. These century-old figures remain the basis for today’s standards." In addition to being outdated, the amount of calories taken from a meal can vary from person to person. Differences in metabolism and digestive efficiency add sizable error bars. Then there are issues with serving sizes and preparation methods. Research is now underway to find a better measure of food intake than the calorie. One possibility for the future is mapping your internal chemistry and consulting a massive database to see what foods work best for you. Another may involve tweaking your gut microbiome to change how you extract energy from certain foods.
