Calories -- are they all the same? Yes and no

October 05, 2012|By CHRIS COPLEY |
Chris Copley/Herald Mail

In the diet world, there are a few vocabulary words that are generally considered as bad words. All too often, "calorie" is one of them.

But that's too bad, because, according to Brittany Smith, clinical dietitian at Meritus Medical Center, calories are simply a measurement of the potential energy of a food.

"Most things you're consuming have some amount of calories based on the carbohydrates, proteins and fat. Your body metabolizes calories to get energy," she said. "So it's pretty much like putting gas in your car when you eat."

Calories provide fuel for the body. Food provides calories. And many people describe food using calories alone, as if that was a complete and thorough description. It's not. Food provides much more than just fuel. It also provides protein — structural material for repair and maintenance — and chemicals — vitamins and minerals  — our bodies need to do different tasks.

What use is a calorie?

First things first. In terms of weight loss or weight gain, calories are your primary measurement.

"If you want to lose weight, you need to consume less calories than you're expending," Smith said. "If you want to gain weight, you have to consume more. It's all calories."

Different types of foods contain different amounts of energy, Smith said. Dietitians say there are 4 calories in a gram of protein, 4 calories in a gram of carbohydrates, 7 calories per gram of alcohol and 9 calories per gram of fat.

So how many calories —  that is, how much body fuel —  does a person need in a day? How many calories should a person eat? It's different for each person. To figure your calorie needs, you can use a simple formula based on your age, gender, height, weight and level of activity. Calculators are available online and in many diet books.

That equation, according to Peter O'Connor, tells you your basal metabolic rate.

O'Connor, who turns 31 this month, is an Advanced Placement chemistry teacher in Boonsboro High School. He teaches his students about calories in connection with chemical reactions in the body.

But he also knows the effectiveness of counting calories. One day, almost two years ago, O'Connor decided he had to handle his weight. He dropped more than 220 pounds in about 18 months.

"I started about December 2010, right after Christmas, at a weight of 378 pounds," O'Connor said. "Then over the course of the year, I watched my calories. I kept a log of the calories I was (burning), and my goal was to get down beneath 180 pounds."

He now weighs about 160 pounds.

Energy storage, energy use

O'Connor said the human body is like a very, very complex machine. At any given moment, a body is pumping blood, repairing skin, growing hair, contracting muscles to focus the eyes, fighting invasive microbes, filtering wastes in the kidneys, transporting oxygen atoms from the lungs to the circulation system, adjusting muscles to maintain balance and hundreds or thousands of other tasks.

All this takes energy to function.

"Energy is a huge portion of what we deal with in chemistry," he said. "A calorie is a measure of the energy a food can produce, and by produce we mean by digesting. So when you read 90 calories on something, it's saying 90 calories of energy can come out after the chemical reactions that take place in your body."

To lose weight, O'Connor said he knew he needed to change his lifestyle. He started by figuring his basal metabolic rate.

"Most calculators  — and I never go to one website or one book (for my calculations); I always averaged a bunch of values," O'Connor said. "Most places would say I was around 3,200 basal metabolic rate calories. That was what I needed to survive, just to maintain. I structured my (diet) to around 1,200 to 1,400 calories. I tried to get closer to 1,400. And now I'm going upward to 15, 16, 17 hundred calories, depending on the day."

He also increased his physical activity to boost the amount of stored fuel his body used. He used a smart-phone app to track his calorie consumption and his daily activity level — his calorie burning. He said tracking the calories-in-and-calories-out process was helpful.

"Some people are very conscious about (recording) their calories — every day, every thing. I did that every now and then, but it was more a guide for what I should be doing. That really helped out," O'Connor said. "There were a couple (other) things that helped out. Friends were always a good support structure. And planning my meals. (Losing weight is) a tough process. If it wasn't for the friends, app and meal planning, it wouldn't have happened."

A food is more than a bunch of calories

O'Connor admitted that during his weight-loss campaign, he allowed himself "tunnel vision." Although he included fruits, vegetables, grains and other whole foods in his diet, he focused primarily on calories and paid less attention to nutrition.

But he knows the difference.

"One hundred calories of McDonald's french fries is equivalent to 100 calories of spinach, if you're only dealing with the amount of energy provided," he said. "Does that mean they have the same nutritional value? Absolutely not."

Tammy Thornton agreed with O'Connor's conclusion. Thornton is a registered dietitian with Washington County Health Department. She also leads Emotional Brain Training workshops, which help people learn about the triggers which lead to overeating.

For her, calories-based descriptions of food are misleading.

"Calories in my opinion are not all the same. Depends on how you frame that," she said. "For example, say I eat 300 calories for breakfast. I could eat a plain white bagel and butter or jam. However, on the other hand, maybe I want to have an omelet with peppers and onions on the side. Each breakfast is about 300 calories. But the difference is the bagel is nothing but carbohydrate. The other breakfast is 300 calories packed with nutrient. And it's going to keep me full a lot longer."

Thornton said foods contain other components, such as fiber and water content. These provide a feeling of fullness.

"Take raisins and grapes," she said. "A quarter cup of raisins is 100 calories. A cup and a half of grapes is also 100 calories. The grapes will be more filling. That's what you need to consider with calories."

So are all calories that same? Should a diet be described solely with calories? Thornton said no.

"Compare 100 calories of carrots to 100 calories of cotton candy," she said. "You're going to get more micronutrients — vitamins, minerals — in the carrots. They enhance our immune system. Whereas the cotton candy — no nutritional value whatsoever."

Calories have a place in a person's diet, Thornton said. They are useful in tracking weight. But overall health is about more than just weight.

"I personally do not like using calories as a measure. I think food composition is the main thing. Protein, healthy fats, carbohydrates," she said. "I know in the past counting calories was a big deal. I would probably use them to assess a diet. However, there are other components of food (than) how many calories are consumed."

Scientifically speaking - what is a calorie?

OK, it's time for Mr. Science. Lesson one: Scientifically speaking, what is a calorie?

Peter O'Connor, an Advanced Placement chemistry teacher in Boonsboro High School, pointed out a contradiction between "calorie" used by dieters and "calorie" used by chemists.

One of calories, he said, is 1,000 times larger than the other.

"When chemists look at the side of a (food package), it's aggravating to us," O'Connor said. "In the U.S., we use ‘calorie' for a term that really should have a different unit. A 100 calories printed on the side of a box or serving — to a chemist, that's 100,000 calories."

A calorie, as scientists use the term, is the amount of energy required to raise the temperature of 1 gram of water at about room temperature 1 degree celsius. That's not a lot of heat.

A food calorie, as used by American dietitians and food processors, is 1,000 times as big as a science calorie. Researchers call this a kilocalorie, or a Kcal. European dieters, O'Connor said, have another term.

"You go to Europe or other countries and you'll see on the sides of their boxes 'kilojoules,'" he said, "because kilojoules is the international unit for energy."

You've been educated. You're welcome.

-- Chris Copley, Lifestyle assistant editor

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