Could you gain A LOT of weight by drinking LOTS of deuterium water?

[Simfish]

You could gain a lot of weight and still have very little body fat! Of course, you'd need to do it for a very long period of time (for the D2O to replace all the H2O in your body). But would there be health risks? haha.

[Dadface]

I like the question and I think the full answer has to be very complicated.Something that comes immediately to mind is that as the D2O builds up the viscosity and other properties of blood and other body fluids will be adversely affected,and the heart ,kidneys and other organs will not be able to function as effectively and start to shut down.

[Skrambles]

The average atomic weight for H2O is about 18, and the average for D2O is about 20. You would add roughly 11% to the water weight you replace. I don't know if that qualifies as "A LOT."

The added weight would probably increase blood pressure, but it's hard to say if the viscosity would be affected very much. The chemistry shouldn't change either, since you wouldn't be changing the number of electrons.

[Proton Soup]

looks like diffusion through membranes would be slower. chemical reaction rates would be slower. evaporation of water on the skin would be slower.

http://en.wikipedia.org/wiki/Isotope_separation

[Borek]

But would there be health risks?

Yes, serious.

http://en.wikipedia.org/wiki/Heavy_water#Effect_on_animals

[Andy Resnick]

The permeability of water and deuterium oxide through aquaporin-1, the main water channel in the body, is about equal:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2154366/

It's odd that deutrium inhibits cell division- I wonder if the effect isn't D2O, but rather the D ion replaces H in proteins etc. (hydrogen-deuterium exchange), altering the activities- I couldn't find a clear study,tho.

http://www.terraformers.org.au/deuterium.html

[Borek]

My bet is that due to the isotopic effect speeds of reactions change, and they are getting "out of sync" - while situation in cells is always dynamic, they are in some sort of steady state or dynamic equilibrium. Deuterium disrupts this equilibrium, concentration of some things goes up, of some goes down - that's a serious problem.