What are calories?

What are calories?

Definition of the term calorie isn't difficult: according to most textbooks on science, it's the amount of energy required to raise a gram of water just one degree Celsius. But how does it relate and relate to caloriecounts that are displayed everywhere from fast food menus to the nutrition labels of snack bars

If we take a look at caloriecounts when we look at caloriecounts, we're generally hoping to understand how much energy we're putting into our bodies. But a nutrition label is never going to give you at least exactly. There are too many aspects to consider, many of that depend on an individual's physiology, and others of which we're still figuring out.

Think about this: In 2020 almonds suddenly were able to provide around 30 percent less calories than they did the year before. Cashews and walnuts went through similar declines in their energy densities. The nuts themselves did not change, obviously, but the method employed to determine calories changed.

This is due to the fact that those who work for the FDA and USDA frequently use the same method used for centuries to measure calories. It was developed in the 19th century (though the exceptions are made in cases where there's more current research available, like for those who are nuts). In the late nineteenth century Wilbur Atwater, decided to measure the energy contained in food by burning the substance while determining how much energy was inside it and feeding the same food to the people and analyzing how much energy was contained in their poop and pee. The difference between energy in and energy out, or so and the calculation of calories, was what led to the numbers that we currently use for macronutrients nine calories in a gram fat, and four in the gram of carbohydrate as well as protein.

In the 19th century this was a massive leap forward in our understanding of the energy density in food. However, for the 21st century it's not quite as clear.

[Related: The truth about keeping track of caloriesIt's a fact!

A calorie of fat in a nut as an example, isn't likely to have the identical as the calorie of animal fat. It's still not clear the reason for this however, it appears that our bodies aren't able to process all foods equally, so certain calories remain in the food and are released into our poop, never having had any effect on our waistlines. (We must note that the research into the calories found in nuts was funded in part by various Nut boards, even though the parties involved didn't create or conduct the research themselves).

The idea of bioavailability just recently become a subject of research, which means there's a lack of data on what other types of food items we're ill-informed about measuring. We've discovered, for instance that cooking food is believed to make the nutrients in it more accessible. We also know that our personal microbes in our gut help determine how much energy we extract from our food such as by breaking down cell walls inside certain vegetables. The Atwater system doesn't account at any time for cooking food, nor does it consider how you cook it and it doesn't take into account different bioavailability levels between different kinds of foods. It's all about how many grams of protein, fat, or carbohydrates are present in the food.

The new studies on nuts don't have a less sophisticated approach as Atwater used--basically, the researchers fed almonds (or cashews or walnuts) to participants, and the study measured their poop in order to determine how much energy was absorbed. It's not that the USDA scientists were bothering to look at one food in particular.

until we can find a better method of quantifying the amount of energy content of a particular food group, it is believed that a calorie, really is just a number we've assigned somewhat arbitrarily to food items. Do not take it too seriously.