MREs have the disadvantage of being extremely caloric. One MRE has enough Calories to satisfy the needs of the average person for a day, particularly just sitting, watching the scenery pass by. They are also very high in sodium. Of course, this is generally true of all the backpacking foods...
A few years ago the US and Singapore got into a disputer over their chewing gum ban. The result was that you could buy nicotine gum in drug stores. Have you been to one of the Disney parks and seen the cleaners using special tools to dissolve and scrape up chewing gum? It's a lot of effort to...
Ray Jardine, well known for doing things like cutting the tags out of clothing, cutting his toothbrush in half, packs made from Cuben, all to shave grams off his weight. Me? I need to get rid of about 30 lbs I carry around my waist before I worry about cutting my toothbrush in half.
We once brought pickled herring to a pot luck. Not a big hit. I'd think that anything that was packed in liquid, particularly an oily, pungent liquid would not be a good choice on a train.
Depending on the date, the Capital Hilton runs some pretty good specials. This is mostly on "off" weekends. I wouldn't recommend it if you have a car because parking is outrageous but it's just a few stops on the Red Line Metro to Farragut North, then a one-block bag-drag. Really, there are lots...
I agree with @OBS Chief in that you should think about convenient backpacking food. I'm not talking about freeze dried chill mac or anything messy like that but more snack foods, Beef jerky, sliced hard salami, sliced cheese, dried fruit, crackers or flat bread. This type of food will keep for...
I believe that there's a bus direct from MSY to Union Passenger Terminal (NOL).
I'm given to believe that the easiest connection between air transport and Amtrak is at Newark (EWR). Baltimore (BWI) also gets high marks.