Feed My Starving Children has a volunteer location in Mesa, Arizona. They are always looking for volunteers. In fact, they have a very simple tool on their site for finding two hours windows where you can help out.
You might be wondering what makes Feed My Starving Children different. They (FMSC) produce three special MannaPack™ meal formulas developed by food scientists to specifically stop malnutrition. These three formulas are Rice, Potato-D, and Potato-W. The Potato-D formula helps with rehydration and replenishing lost nutrients. The Potato-W formula complements breast feeding to help mothers who are struggling to get the nutrients they need.
Feed My Starving Children also has an excellent food distribution network and the help of volunteers. Volunteers donate all of the money and package the foods.