I suppose that it rather depends on whether you know that the person wants to have gained weight or not. If you do, then your knowledge of that individual person will dictate how best to tell her/him.

More generally, for people whose preference for the matter is unknown, there is much to be said for "you look well" or some other general compliment on the person's appearance.

I have just finished "London Tramways" by John Reed. Does that count?

This looks fun.

A cake connoisseur despairs...

Looks like you all had such fun - shame that I missed it. Some very impressive outfits!

I'm not sure where the purported 1/10 figure comes from - these things are inherently hard to measure - but this one is easy to avoid by following the simple rule of not sending large quantities of money to people that one's never met before.

Interesting. Are there any particular keywords for which people search?