almost every time i play CIV Warlords, i enter inside some city and its show me starvation in red letters and the city decrease how i solve this condition??
thx for all
hope you understand me....

work a farm or pasture. if you dont have any bonus resorse, irrigate a grasland. if you not are able to work an irrigated grasland you will need to settle the citys in better spots.

Basically you have a food shortage

You need two food for every citizen so you need to work some tile with equal or more (farmed grassland = 3, cottaged grassland =2) to balance those with less (mined grass hill = 1 food).

Check out the war academy it should help you with and a lot of other stuff.

http://www.civfanatics.com/civ4/strategy/