Guatemala is very similar to south of Mexico with lots of corn-based food, beans and, unfortunally, tradition of using lard when cooking. "Tamales", even without meat, are made with animal fat. Look for "frijoles refritos" (refried beans) in supermarkets and tortillas in the streets. Fruits and vegetables are good, but a bit pricier than in Mexico. It's also possible to find ice-cream without milk - ask "sin leche" in any heladeria/neveria.