So it was supposed to be this simple. Calories eaten less calories burned is the simple formula for weight loss or gain. But for most of us who have experimented with multiple diets, we know that it is absolutely not true. Ask any bodybuilder, even from the 50s, and they will say it’s not true. Finally science is trying to catch up.
Recording the calories your consume through Fitbit and quantifying calories based on the information on food packaging is may seem like an exact science but it is not. They are just best guesses. Worse yet, as scientists are increasingly finding, some of those calorie counts are flat-out wrong.
I’ll avoid going on the details on how calories are calculated. You can read it up on links given at the bottom. But what you need to know is that depending on the calorie-measuring method that a company chooses – the FDA allows two more variations on the theme, for a total of five – a given serving of spaghetti can contain from 200 to 210 calories.
How about the inaccuracy of serving size? Just chefs heaping on a extra french fries or more sauce can cause a dish to exceed it’s listed caloric value.
Even if the calorie is accurate, there is apparently significant variations between the total calories and the amount our bodies extract. “All the nutrients – the fat and the protein and things like that – they’re inside this plant cell wall.” Unless those walls are broken down – by processing, chewing or cooking – some of the calories remain off-limits to the body, and thus are excreted rather than absorbed.
Richard Wrangham, an anthropologist at Harvard University, and his colleagues have since shown that cooking unlaces microscopic structures that bind energy in foods, reducing the work our gut would otherwise have to do. It effectively outsources digestion to ovens and frying pans. The same effect holds true for meat: there are many more usable calories in a burger than in steak tartare.
This means that Industrial food processing, which subjects foods to extremely high temperatures and pressures, might be freeing up even more calories. Hence the difference in the caloric values between cooked and uncooked food
There’s also the problem that no two people are identical. Differences in height, body fat, liver size, levels of the stress hormone cortisol, and other factors influence the energy required to maintain the body’s basic functions. Two people of the same sex, weight and age, may differ by up to 600 calories a day – over a quarter of the recommended intake for a moderately active woman. Even something as seemingly insignificant as the time at which we eat may affect how we process energy. In one recent study, researchers found that mice fed a high-fat diet between 9am and 5pm gained 28 per cent less weight than mice fed the exact same food across a 24-hour period. The researchers suggested that irregular feedings affect the circadian cycle of the liver and the way it metabolises food, thus influencing overall energy balance
Another factor that is now being studied on is the trillions of tiny creatures that line the intestines. The diversity of microbes that each of us hosts is as individual as a fingerprint and yet easily transformed by diet and our environment. And though it is poorly understood, new findings about how our gut microbes affect our overall energy balance are emerging almost daily.
Other evidence suggests that gut microbes might affect weight gain in humans as they do in lab animals. Take the case of the woman who gained more than 40 lbs after receiving a transplant of gut microbes from her overweight teenage daughter. The transplant successfully treated the mother’s intestinal infection of Clostridium difficile, which had resisted antibiotics. But, as of the study’s publication last year, she hadn’t been able to shed the excess weight through diet or exercise. The only aspect of her physiology that had changed was her gut microbes.
At the end of it all, we do have to re-look at calorie counting and instead have a closer look at overall balance of food and satiety. Due to the numerous factors that affect calories absorbe, we definitely have to look at a personalised nutrition plan for each of us for optimum health.
Something that my interest you further – Nutritional value of food
Adapted from http://mosaicscience.com/story/why-calorie-broken