Try to buy eggs and you know that size does matter. But seriously is there any significant difference in nutritional composition in small/medium/large/extra-large eggs.
I normally avoid buying the small or extra-large ones because I think they are “genetic abnormalities”. Is there any truth in that ? Also, does the same hen sometime lay small eggs and sometimes large ones - or are there hens who are consistent about this ?
By that logic, jockeys and basketball players should be considered “genetic abnormalities”. I guess we should avoid eating them at any rate.
All that is being done here is selective breeding for a desired characteristic, here either large or small eggs. Our chickens always produce pretty consistant eggs, some consistantly smaller than our average from one particular hen, one consistantly larger from another. I have no data that they are different nutritionally, other than the fact that larger ones have more calories. I would not expect there to be other nutritional differences.
Larger eggs are bigger.
What this means is, on an egg-per-egg basis, a larger egg will have more of everything. I’ve not come across any information that the proportions of the components differ, though.
From a cooking standpoint, egg size can matter because most US recipes are optimized these days for the “large” size egg.