Yes, and more than that. Fish do not need this food, assuming they are healthy to begin with and not fry. Automatic feeders are also dangerous, they are known to stick and dump food in.
If you intend being away a week, the fish will be fine; do a major water change the day before, and feed them normally after. If the vacation is more than two weeks, either again forget feeding, or find a reliable person to do it; preparing individual packages of food for a tank, instructions to feed only one of these and then maybe once or twice a week--lots of options.
Holiday feeding blocks are made from layers of calcium and food. Its a bit like a birthday cake with multiple layers, except you have calcium, food, calcium food, calcium, instead of cake and jam.
If the pH of your tank water is less than 7.0, the calcium can dissolve very quickly and release all the food. If it isn't eaten straight away, it breaks down and produces ammonia.