It's sort of a sliding scale. Sandwich ziploc bags are light, but get really soft when filled with hot water and require the support of something like a fitted cozy. Hard bits such as noodles can poke holes in them through rough handling or mashing of the food bag. Freezer ziplocs handle boiling water just fine and don't get holes. The storage grade is intermediate. It works much better than sandwich bags and not as well as freezer bags. Boil-in bags and some of the other things suggested above also work fine. Another option is to same the zip-closed bags for nuts (Blue Diamond is one brand), Splenda sweetener, and other food products. They are a bit heavier than ziploc freezer bags, but they are larger and do the job well. They may have fewer plasticizers to get into the food.
Good closures keep animal-attracting odors down. Repackaging commercial backpacking meals is a great idea, but should be done close to the trip to avoid oxidation.