Vegetarian/Vegan
There is a difference between vegetarian and vegan. The complete vegetarian diet is free from any animal products (meat, dairy, eggs, fish etc). Veganism is a lifestyle, where one does not buy, eat, wear, or use anything that comes from animals.
By that definition I am not vegan, but I have been fairly successful over the past 2 years now with the vegetarian approach (with some dairy, egg, and fish here and there). I have been packing this stuff called the ultimate meal (ultimatelife.com) with a stick blender and large cup (and apples/bananas) for making smoothies in hotel rooms. It is absolutely worth every penny, and consists of high quality ingredients, including some of the most potent forms of protein you can have (plant based). I try to make 2 meals (smoothies) a day, although that means you still have to pack additional food if you want to cover time flying, that is what I have found to be the hard part.
I recently worked with a vegetarian pilot, he said it was not too difficult to accomplish if read up on travel and vegetarian eating. His recipes were out of the book Fit for Life, and he said he never felt so good for years.
On a side note, I did get some good advice once. When you shop at a grocery story, try to buy around the perimeter of the store, because that is where you will find more of the natural foods (produce, meat, dairy, etc.) According to some health experts, you should avoid processed foods as if your life depends on it (refined sugar, refined flour etc.) which are usuallly in the middle of most grocery stores.