An idea and some research

[boingy]

If making a palatable low or zero alcohol beer was easy then someone would have made one by now....

(and there is a forum rule about not discussing distillation)

[darkonnis]

I agree, using a glass vessel wouldn't be the safest course of action if you plan to use something which creates a vacuum or drop in pressure.
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As for distillation, depending on the use of the product it is legal. In the UK you can produce quite a volume of fuel for personal use before you have to consider paying tax/duty on it hence my mentioning of it. If any of the mods want what I put removed then I will of course, but seeing as we've started down this road; albeit without mentioning the actual word of distillation, I thought it best to offer the safest way to do it without causing harm or injury and without breaking the law.

[orlando]

Drink less, exercise more, has to be the best option. I would rather give up drinking beer than drink the results of the alternatives suggested. Have none of you tasted alcohol free beer? It's terrible beyond words.

[killer]

I seem to remember from school chemistry lessons that you could get devices that went on a tap and produced a vacuum in some way by making use of the water flowing through them. I'm not sure what they were called, nor if you can still get them.....

Good point. I'd forgotten about that, I had to look it up as couldn't remember the name of it.
Venturi effect.

Not sure it will reduce pressure / boiling point enough though.

They are sometimes called water jet vacuum pumps and are available for 30 - 50 quid usually, and you can find them in lab equipment companies or even make them at home.
They do work very well - I sometimes use them at work. For example, they can reduce the boiling point of DMF from about 153° to 60° at maximum flow for a typical house water supply and a well sealed system.
A solid glass demi-john should take the maximium type of pressure this vacuum pump will make (about 20mBar).
In terms of reducing calories you will still have the sugars...
The vacuum will of course remove the aromatics, but I think it's an interesting experiment, especially on maybe a 5L scale if you dry-hopped after.