What are calories?

What are calories?

Defining the definition of calorie isn't difficult: according to the majority of textbooks in science, is the energy needed to raise a gram of water one degree Celsius. How does this apply and relate to caloriecounts that we see all over everything from menus for fast food to nutrition labels on snack bars

If we take a look at caloriecounts when we look at caloriecounts, we're generally trying to find out how much energy we're pouring in our body. However, a label on a food item is never going to be able tell you that, at least not completely. There are too many elements to consider, many of which depend on the individual's physical condition, and others that we're still working out.

Consider this: Starting in 2020 nuts suddenly appeared to have about 30% less calories than they had in the year before. Cashews and walnuts went through a similar drop of energy density. Nuts ' density didn't change obviously, but the method employed to determine calories did.

That's because those who work for the FDA and USDA generally still employ an outdated method for measuring calories. It was developed in the 19th century (though some exceptions are made when there's more current research available, like for peanuts). In the 18th century Wilbur Atwater, a scientist from the late 19th century decided that it was time to quantify the energy content in foods by burning the food in order to determine how much energy was present in it as well as feeding the same food items to people and then observing how much energy was present in their poop and pee. The distinction between energy that was in and the energy that went out, so to speak and the calculation of calories, was what led to the numbers that we employ for macronutrients in the present nine calories in one gram of fat, and four in one gram of carbohydrate or protein.

For the 19th century this was a huge leap in our understanding of the energy density in food. However, in the 21st century, this doesn't seem to be quite right.

[Related: The truth about measuring caloriesThe truth about counting calories

The calorie of fat found in nuts, as an example, isn't likely as if it's the same as the calorie that comes from animal fat. Although it's not clear why this happens but it is believed that our bodies can't process all foods equal, which means that certain calories remain in the food and exit in our feces, but haven't any impact on our waistlines in any way. (We should be aware that the calories-in-nuts research was partly funded by a variety of board members, although those who were involved in the research didn't actually design or conduct the research themselves).

The concept of bioavailability has just recently become a subject of investigation, and therefore there's not a lot of information regarding other types of foods we may be improperly quantifying. For instance, we're aware that cooking food can seem to help make the nutrients within the food more readily available. We are also aware that our individual microbes living in our intestines help determine how much energy we extract from our food in various ways, such as degrading the cell walls of certain vegetables. The Atwater system does not account at any point for cooking food regardless of how you cook it, neither does it take into account differences in bioavailability between different types of food items. It just goes by how many grams of protein, fat, or carbohydrate is present in the food.

The new nut research doesn't even employ a more advanced technique than Atwater employed. The researchers fed almonds (or cashews, walnuts or even cashews) to participants, and examined their poop to determine how much energy was taken in. It's not that the USDA scientists took the time to look at one food item in particular.

If we aren't able to find a more effective method of quantifying the amount of energy content of a particular food group that is it is believed that a calorie is, in reality is a term we've assigned somewhat arbitrarily to food. Be careful not to consider it a serious matter.