Got back last Wednesday from a 2 week holiday in Botswana (Safari). It was AMAZING! We stayed in some wonderful locations (Victoria Falls, Okavango Delta, Chobe and Kalahari).
Lots of jeep trips (3-6 hours), plenty of eating (four meals a day - high tea obligatory as were sundowners!) BUT I only gained 2lbs!
I didn't think I did much exercise, but there was a lot of travel (2 x 11 hour flights, 2 x 2 hour flights and 8 light aircraft flights of 45 mins to an hour, 1 helicopter flight)
I also brought back a horrid cough, but it seems to be going now.