I thought creatine might be good for cycling, but apparently it may not be the thing to use on long tours. Actually, the only thing I have ever heard it being used for was before and after lifting weights. Actually, eggs are an excellent source of absorbable protein where absorbtion is the matter, but then there is the matter of fat. If one is using the fat then perhaps it is ok, but excess fat in the diet has been more than just linked with colon cancer and other maladies. Eggs are loaded with protein, and where is all that protein mostly concentrated? In the yolk with the fat. If you follow the Pritikin plan, you know to dump the yolks and use the whites. However, I think high fat diets are mostly associated with what is known as the typical western diet which is known to be pretty much loaded with fatty foods from many sources. Eating plenty of eggs on tour would be ok as long as one watched his or her intake of fats from other sources. When on long tours and megadosing with water soluble vitamis and keeping up on the others, and drinking brewer's yeast a few times a day, I am pretty sure my energy levels were higher than usual. I have also carried a full complement of minerals.
Any nutritionist might tell you all you really need is a good, balanced diet of fresh fruits and vegetables, whole grains and cereals, and this is true within limits. But consider pedaling a fully-loaded touring bike three thousand miles over varied terrain, hills, mountains, rolling, etc. It might call for supplements. I will tell you something that I know will provide a long, even flow of energy. You take a good quality juicing machine. Juice a 50-50 combination of carrot and celery juice. Make half a quart or a quart. Drink it down. Go out for a long ride in the hot sun. See if you can feel the difference. I always could. The first time you might not notice it too much, but the second or third time you will feel a major difference as compared the energy you might be used to from just regular meals. Nutrition makes a difference.
It will not hurt you to take nutritional supplements on tour. It may add a little weight but that's ok.