> So here's another back of envelope calculation.
>
> Embedded energy in manufacture and distribution of confectionery =
> 43MJ/kg. [1]
> Nutritional energy in chocolate 22MJ/kg [2]
> cycling 1km to shop at 20km/hr = 100 watts for 3 minutes = 1.8 kJ.

> Total energy used = 1.8 *43/22 = 3.5 kJ per km
> Driving = 2700kJ per km [3]
>
> so cycling seems to be in the range of 100 to 1,000 times more energy
> efficient than motoring. I think that you'd have to find some pretty
> exotic food (or an arithmetical error in my analysis) to make that bit
> of hyperbole from Chris Goodall stand up.