We tell lies to children because the truth is too hard for them to understand at their level of knowledge. (See, for example, models of atoms that have a nucleus and protons and electrons buzzing round it.)
So, with that in mind, children learn that one calorie is the amount of energy needed to raise 1 g of water by 1 degree c.
But what does that actually mean for a human body? How is a calorie in fat worked out? How is a calorie in sugar worked out? How do we know they're equivalent?
> So, with that in mind, children learn that one calorie is the amount of energy needed to raise 1 g of water by 1 degree c.
I find this to be wonderfully ironic, because the nutritional calorie is 1000x larger than the physics calorie. In nutrition, one calorie is the amount of energy needed to raise 1kg of water by 1 degree C. So yes, it's entirely possible that this fellow didn't know what a "calorie" was in the realm of nutrition.
Yep. When you see "calorie" on US food labels, that's actually a big-C Calorie, or food calorie, which is equal to a kilocalorie from regular physics.
If it were regular physics calories, the energy content of food would be nowhere near enough to sustain us. A typical human body at rest will consume around 8 megajoules per day, or about 2 million calories. But that's only about 2 thousand big-C food Calories.
Exaggeration for effect? It's perfectly plausible that a mathematician / physicist would have a weak layman's understanding of energy balance in nutrition.
One important thing in higher education for math and physics is to be able to perform detail technical computations or modeling for phenomenons. In common high school and undergraduate physics class, it only requires students to be able to come up models with intuitions. But in graduate schools, you are trained to examine each step to make sure nothing is left out or based on assumptions that are wrong in your mind.
Therefore a lot of time you are not sure what something is until you re-examine all postulates that you learn when you are young.
An MIT-trained physicist should know the common name for a unit of energy. Sure, he might not remember the conversion from joules to calories, but to have never heard of it?
That's taking a literal reading ("I didn't know what a calorie was"), but perhaps he was referring to a more nuanced understanding ("I didn't understand how energy was used by the body"). That interpretation wasn't clear from the text though -- it seemed an overwrought attempt to portray an "Aw shucks, I didn't know what I was doing!" attitude.
"Calorie" in the context of nutrition has a different meaning than "calorie" in the context of physics. Three orders of magnitude different, to be precise. It's entirely plausible that he had no idea of the special nutritional definition, since you'd never encounter that outside of nutrition, and things like food labels almost always fail to make the difference clear.
Comments
You are an M.I.T.-trained mathematician and physicist. How did you come to work on obesity?
...I didn’t even know what a calorie was.
I call bullshit.
We tell lies to children because the truth is too hard for them to understand at their level of knowledge. (See, for example, models of atoms that have a nucleus and protons and electrons buzzing round it.)
So, with that in mind, children learn that one calorie is the amount of energy needed to raise 1 g of water by 1 degree c.
But what does that actually mean for a human body? How is a calorie in fat worked out? How is a calorie in sugar worked out? How do we know they're equivalent?
> So, with that in mind, children learn that one calorie is the amount of energy needed to raise 1 g of water by 1 degree c.
I find this to be wonderfully ironic, because the nutritional calorie is 1000x larger than the physics calorie. In nutrition, one calorie is the amount of energy needed to raise 1kg of water by 1 degree C. So yes, it's entirely possible that this fellow didn't know what a "calorie" was in the realm of nutrition.
Wait, what? That would be one kilocalorie. And that's what's listed on most food?
Yep. When you see "calorie" on US food labels, that's actually a big-C Calorie, or food calorie, which is equal to a kilocalorie from regular physics.
If it were regular physics calories, the energy content of food would be nowhere near enough to sustain us. A typical human body at rest will consume around 8 megajoules per day, or about 2 million calories. But that's only about 2 thousand big-C food Calories.
Forgetting or ignoring this difference results in amusing things like the beer and ice cream diet: http://training.fitness.com/weight-loss/beer-ice-cream-diet-...
Exaggeration for effect? It's perfectly plausible that a mathematician / physicist would have a weak layman's understanding of energy balance in nutrition.
You're probably right. Maybe in an audio interview the irony would have come through.
Why do you say it as bullshit?
One important thing in higher education for math and physics is to be able to perform detail technical computations or modeling for phenomenons. In common high school and undergraduate physics class, it only requires students to be able to come up models with intuitions. But in graduate schools, you are trained to examine each step to make sure nothing is left out or based on assumptions that are wrong in your mind.
Therefore a lot of time you are not sure what something is until you re-examine all postulates that you learn when you are young.
> Why do you say it as bullshit?
An MIT-trained physicist should know the common name for a unit of energy. Sure, he might not remember the conversion from joules to calories, but to have never heard of it?
That's taking a literal reading ("I didn't know what a calorie was"), but perhaps he was referring to a more nuanced understanding ("I didn't understand how energy was used by the body"). That interpretation wasn't clear from the text though -- it seemed an overwrought attempt to portray an "Aw shucks, I didn't know what I was doing!" attitude.
"Calorie" in the context of nutrition has a different meaning than "calorie" in the context of physics. Three orders of magnitude different, to be precise. It's entirely plausible that he had no idea of the special nutritional definition, since you'd never encounter that outside of nutrition, and things like food labels almost always fail to make the difference clear.