Is there any value in rethinking how we measure the energy content of food?

(Crow T. Robot) #1

I’ve thought about this quite a lot after discovering the fallacy of CICO, but never asked the question before.

Why don’t we express food value in terms of how many ATP molecules are potentially available in it, rather than how much heat we can get by burning it with fire (AKA calories)? Any problem doing that? Would it even be helpful?

Seems to me like it would kind of be the great equalizer, and probably more useful, but I might be looking at it too simplistically.

Interested in your thoughts.

(You've tried everything else; why not try bacon?) #2

That’s a brilliant idea. The answer to your question is that the caloric measurement was developed before Krebs described the Krebs cycle and the construction and metabolism of ATP, and inertia has kept us thinking in those terms ever since.

But you got me thinking (always dangerous), and it would seem that perhaps we should even ask the more fundamental question of whether it is even relevant to know the energy potential of food in the first place.

(Michele) #3

I started writing this on another thread but thought I would put it here instead. This is me hypothesising. I don’t see how the CICO thesis can be entirely representative. It’s far too simplistic. Haven’t calorie values been worked out in a lab rather than a human body 1g carb 4kcal etc?
Not all foods are made of the same components and get put to the same end use. Ignoring non nutritional carbs for the moment (flour, sugar). So thinking about nutritional carb carrying foods (veges) they also contain fibre. Then there’s proteins and fat. Each are constituted from different base products/building blocks. Sure some can be pulled apart and made into something else or stored in a different format, surely that takes energy to do that?
In addition when an essential component is missing the body has to malfunction or work around the problem (thinking T1D here with sugar in urine). Then we have carbs vs net carbs because of fibre.
So what happens when a person’s metabolism increases? Is there an overall increase in body temperature? Or more resources put into repairing, rebuilding etc, where does the extra go if it’s not stored as fat, especially when deliberate exercise is not increased?
I might not be expressing myself well so apologies if this seems garbled.