Calculating Food Calories - burning a marshmallow

(Joey) #1

If you’ve ever wondered about how “calories,” “kcal,” and “Food Calories,” can be determined (and the differences), then this 8 minute snippet from Khan Academy offers a wonderful blackboard example, walking you through the math.

Loads of fun with a Bunsen Burner and one poor marshmallow… :nerd_face:

BTW, once you appreciate how calories are determined, if you’ve ever suspected that the link between how the “caloric content” of food (as shown on nutrition labels) actually affects your body after you’ve eaten it, well, then this ought to help fortify your suspicions. :wink:

(Bacon is a many-splendoured thing) #2

My other gripe is that a (kilo)calorie is defined as the amount of heat released by burning the food in question, which is completely irrelevant to the human body, which counts the energy yield in ATP molecules. Carbohydrate and glucose both yield about the same number of ATP molecules per gram, after subtracting the ATP cost of metabolising them.

Protein, on the other hand, yields a lot less ATP per gram, and this is because of the energy cost of deaminating the amino acids and then converting them to either glucose or a fatty acid (some amino acids go one way, some go the other way, and a few go both ways) before they can be metabolised. This is why, under normal circumstances, protein contributes nothing to meeting the body’s energy needs.

#3

wowza :partying_face::exploding_head:

I truly thought I was personally gearing up for a space shuttle mission thru NASA :laughing: Astronaut Karen if I can truly understand those equations in the end, I almost did not HAHA

another key being 0 nutritional value. yea eat that ‘for what’ reason cause it gives ‘0’ to us. supports 0 nutrients for body thriving effects, vitamins, minerals we require for life and adds squat other than ‘hits that sugar addiction’ and roller coaster ride of eat more sugar after that ‘4 controlled marshmellows’ we wanted :flushed:

but again I see those calculations on the board as it went down and I am AWED by it all but then again I sure don’t get galaxy worm holes thru physics calcs or how to calc light speed time and more but darn, ALL WE SEE HERE in true science is those 4 marshmellows IN that serving ‘convert to darn near no calories’ and ‘AIN’T we ALL been there’ on that useless info but true science it is :slight_smile: :wink:

fun video and good info put out and good conversation on it I would think! cool

(Central Florida Bob ) #4

It never ceases to amaze me how something as useless as the calorie content of food being burned could become so implanted in the consciousness of the world.

I’ve been around people who know nothing about any of the metabolic processes involved, and wouldn’t know a resting metabolic rate from rest stop on the interstate, but that spout off about “watching calories” and “eat less - move more.” Any question about how many calories they think they need and why, or what kind of variation in calories between two pieces of food would just result in blank looks.

But Everybody Knows all you gotta do is burn more calories than you eat.

(Joey) #6

So true. Imagine if we got all worked up over ensuring we exhaled just as much as we inhaled… you know, to ensure we don’t oxidize and explode.

(Bacon is a many-splendoured thing) #7

It’s a holdover from the time, well over a century ago, when all we knew how to do was to burn food to see how much heat it released. As though people were steam engines, and we derived our energy from literally burning our food inside our bodies.

But if “a calorie is a calorie,” then we don’t get to blame Coke and Pepsi for the effect of their products on our bodies, so I suspect that the commercial interests at play have something to do with the persistence of this way of thinking.

#8

suspect? nah, they are way involved to the up the greed profits! I ain’t go no doubt on this one :wink:
You’re being kind saying suspect on this one HA

(Megan) #9

ROFL