What is a Calories?

The word calorie carries a lot of weight. We know we're supposed to avoid too many of them, but things get more complicated after that. What, exactly, are calories, and how do I burn them?


A calorie is a unit of heat energy that fuels your body, making it possible to move, breathe, think, sleep—and even digest food to make more energy.While there is some disagreement about who first coined the term calorie, we know the French chemist Antoine Lavoisier used it in experiments he conducted during the winter of 1782–1783. He used a device called a calorimeter to measure how much ice melted in a metal container due to the heat emitted by guinea pigs housed inside it. Over time, that measurement was refined by other scientists to mean the amount of energy needed to raise the temperature of a kilogram of water by 1°C—what's known as a kilocalorie.


The food calorie and a kilocalorie (kcal) are technically the same thing, but we use the term calorie rather than kilocalorie because of an American chemist named Wilbur Olin Atwater. In the late 1880s, Atwater traveled to Germany to study at physiologist Carl Voit's laboratory, where Voit was researching the nutritional value of food and animal feed. Inspired by that research, Atwater took measurements of different foods with a bomb calorimeter—a device that essentially measures the heat in food when burned—by having study participants eat, and then measuring and subtracting the amount of heat leaving their bodies through respiration and waste. He used a respiration calorimeter to measure their breath and a bomb calorimeter to burn their poop, and from that calculated just how many calories were left in their bodies to be used. When writing about his research, Atwater used the word calorie (kcal wouldn't be used in America until 1894, when it was published in a physiology textbook).


Based on his experiments, Atwater created a system for calculating the calories that human bodies can get from our food. There are three types of food nutrients that deliver caloric energy—fats, proteins, and carbohydrates—and Atwater arrived at a caloric measurement of each: A fat gram has nine calories, while a gram of protein and a gram of carbohydrates each have four. That system was modified by USDA scientists in 1973, but it's otherwise still the basis for how calories are calculated today.



When you eat, enzymes in the mouth, stomach, and intestine break down nutrients by turning fats into fatty acids, sugars into simple sugars, and proteins into amino acids. Then, using oxygen cells throughout your body, these components are broken down into energy—a process known as metabolism.


Most of the calories we burn each and every day are used just to keep our body functioning, with about half going toward powering our major organs—the brain, liver, kidneys, and heart. We use the rest for physical activity and the process of converting food to energy. Anything not used by the body is then stored, first in the liver and eventually as fat cells.

Some foods, like honey (carbohydrates), are easily digestible, whereas nuts (a mix of carbohydrates, fat, and protein) can't actually be fully digested at all. There are also digestibility differences within the same type of food. For example, in plants, older leaves tend to be sturdier (and therefore harder to digest) and less caloric than younger ones. Most significantly, especially in terms of human evolution, whenever we cook or process food, the body can get more calories as compared to that same food eaten raw. All of this has an impact on the amount of calories we can actually use.


There's no food you can eat to speed up the rate at which you burn calories (changes from foods like spicy peppers are fleeting), but factors like age and rapid, drastic weight loss can slow it down.

Building more muscle can increase your metabolic rate (although how much is debatable), since muscle requires more energy to function than fat does. And while cardiovascular exercise might not permanently boost your metabolism, it does burn calories; just how much depends on your weight and how vigorously you exercise.


Examples of higher calorie burning exercises include cycling and running, but almost every activity burns something, so you could potentially burn more calories throughout the day by consistently doing low-energy activities like gardening or pacing during a conference call than you would during 30 minutes of fast cycling.



We still use the Atwater system for calculating food calories, but it's far from perfect. For one thing, a USDA study found that people absorbed fewer calories from nuts than had been estimated under Atwater's system—a serving of almonds, for example, provided not 170 calories, but 129. There's some evidence that people tend to digest food at all sorts of different rates too, depending on the individual makeup of our gut bacteria, meaning that the absorption of calories may differ from person to person.


Scientists now believe the numbers on food labels are more of an estimate than a precise measurement. While companies are required to provide caloric information on food labels, the FDA doesn't specify exactly how those calories should be calculated. Some companies, like McDonald's, send their food to a lab for measurement, while others estimate the total by adding up the calorie count for each food component from the USDA's massive food composition database. As scientists continue to refine how we calculate calories, we'll come to have a better idea of the energy we can actually get from these different foods.


*source: mentalfloss.com/article/541378/what-calorie


How many calories is that human? A nutritional guide for prehistoric cannibals

calories is that human?

If you were to eat, say, another human being, how many calories would you be taking in? That’s a valid question not only for health-conscious people, but for anthropologists, too. You see, our human ancestors were cannibals — but we don’t really know why. Did they kill and eat each other like they would a mammoth or a wholly rhino — for the meat? Or were they practicing some sort of religious ritual?

To answer that question, James Cole, a senior lecturer in archaeology at the University of Brighton, looked into the nutritional value of a human being and then compared it to that of other animals our ancestors dined on. He found that eating a man provides fewer calories than gobbling down a mammoth, bison, or red deer. And that suggests that our ancestors ate each other not for nutrition but for some other purpose — maybe as a form of funerary or cultural ritual. The findings were published today in the journal Scientific Reports.


Today, cannibalism is a taboo (although it’s still practiced by some remote tribes). But we have evidence that our prehistoric ancestors — including Neanderthals — dined on human flesh. All over Europe, bones of early humans, collectively called hominins, show butchering marks similar to those found on animal remains. Some hominin bones are clearly chewed, or broken to extract the marrow; sometimes the base of the skull is missing, meaning someone was trying to get to the brain. Researchers mostly believe that early humans were eating the dead because they provided easy access to tasty steaks, Cole says. But there are still questions about how often we practiced cannibalism — and why.

In modern humans, cannibalism happens for a variety of reasons: some people have resorted to eating human flesh after surviving plane crashes; in some cultures, the dead were eaten as part of ritualistic process; other times, dining on humans is a sign of sociopathic behavior (think Hannibal Lecter). So how do we know that cannibalism in early humans doesn’t have some meaning other than pure nutrition? Cole wanted to know, and thought of answering the question by calculating the nutritional value of humans vs. animals.

“He’s bringing a different perspective to the question,” says Hélène Rougier, an associate professor of anthropology at California State University, Northridge, who did not work on the study. “It’s an interesting approach.”


*source: https://www.theverge.com/2017/4/6/15189678/prehistoric-cannibalism-humans-calories-nutrition-neanderthal-behavior


Fat vs calories: What is more important to burn for weight loss?

Fat vs calories

Weight loss is all about eating healthy, burning fat or calories to come to a good shape. Eating less and moving more is said to be the ultimate hack to shed kilos in a short period of time. But there is a huge difference between burning calories and burning fat. Both have a different effect on the body and even the outcome of burning them is different. The major question still remains the same, what is foremost, burning fat or calories? Let's find out the answer to this complex question.

The difference between burning fat and calorie

Calories from food and beverages you consume either get used immediately or are stored as energy reserves. Our body converts unwanted calories to triglycerides, which are stored in fat cells. When you exercise, your body draws energy from recently consumed calories as well as energy stored for fuel. If you decrease your calorie intake and increase your physical activity, the portion of the energy you expend comes from the fat stored in the body.


As you know that you need to consume fewer calories and burn more in order to burn 1 kilo of fat. So, when you follow this trick of consuming fewer calories and involving yourself in physical activity, you technically end up burning both. Burning calories forces your body to access energy stored in the form of fat. Similarly, burning fat, while keeping your calorie intake low, will make your body use more of the calories you have just consumed and store less of them.


The end result

If you eat more calories than you burn, then of course you will not lose weight and fat from the body. Even if you workout for a good amount of time in the gym and consume the same amount of calories as soon as it is depleted, it will be stored as triglycerides in the body.

So, burning fat only provides a temporary solution to your weight loss problem. If you want to lose body fat, the only solution is to create a calorie deficit.

*source: https://timesofindia.indiatimes.com/life-style/health-fitness/weight-loss/fat-vs-calories-what-is-more-important-to-burn-for-weight-loss/articleshow/70435079.cms


Calorie Calculator

Powered by the USDA National Nutrient Database, the Food Calorie Calculator below allows you to choose from thousands of foods and brands, and see nutrition facts such as calories, fat, protein, carbohydrates, fiber and sugar. Get started by entering your food and drink choices under “Keywords”. If you want a quick tally of your choices, click “Add” next to the item to display a summary below.


Calorie Calculator Online: https://caloriecontrol.org/healthy-weight-tool-kit/food-calorie-calculator/


*source: https://caloriecontrol.org/healthy-weight-tool-kit/food-calorie-calculator/


Calories for Kids

Calories for Kids

*source: HealthyChildren.org

How Many Calories Do Kids Need?

Kids come in all sizes and each person's body burns energy (calories) at different rates, so there isn't one perfect number of calories that every kid should eat. But there is a recommended range for most kids between 6 and 12 years old: 1,600 to 2,200 per day, depending on how active they are.

When they reach puberty, girls need more calories than before, but they tend to need fewer calories than boys. As boys enter puberty, they may need as many as 2,500 to 3,000 calories per day, especially if they are very active. But whether they are girls or boys, kids who are active and move around a lot need more calories than kids who don't.

If you eat more calories than you need, the body changes extra calories to fat. Too much fat can lead to being overweight and other health problems. Only your doctor can say if you are overweight, so check with him or her if you're concerned. And never go on a diet without talking to your doctor!.

High-calorie foods — such as sugary sodas, candy, and fast food — quickly add up to too many calories. Instead, eat a healthy, balanced diet. Exercising and playing are really important, too, because physical activity burns calories.

How the Body Uses Calories

Your body needs calories just to operate — to keep your heart beating and your lungs breathing. As a kid, your body also needs calories and nutrients from a variety of foods to grow and develop. And you burn off some calories without even thinking about it — by walking your dog or making your bed.

But it is a great idea to play and be active for an 1 hour or more every day. That means time spent playing sports, playing outside, or riding your bike. It all adds up. Being active every day keeps your body strong and can help you maintain a healthy weight.

Watching TV and playing video games won't burn many calories at all, which is why you should limit those activities to no more than 2 hours per day. A person burns only about 1 calorie per minute while watching TV, about the same as sleeping!


source: https://kidshealth.org/en/kids/calorie.html