I understand the confusion and there is even a whole thread about it somewhere on here. But let me see if I can explain.Where did you get this information? I can't work out how you get those numbers?
Per 100gm, eggs have 12.2gm protein, 9.9gm fat.

In that egg weight that you note it includes water weight which does not give energy or calories. If eggs are only protein, fat, and vitamins or minerals and moisture content.. According to weight, I agree with your numbers. But according to calories is where I derive my figures from since water has zero calories it doesn't count towards intake value. The birds will simply drink more or less water to meet their hydration needs. And they eat according to their energy needs. In other words if you convert your figures to calorie count instead of weight is where I derive mine from.
So, protein is 4 calories per gram and fat is 9 calories per gram. So rounding the figures you provided... 12 g of protein is 48 calories. And 10 g of fat would be 90 calories. You didn't state an overall calorie count for your 100 g chicken egg, but if you use these calorie counts compared to the total... THAT is where I get my numbers from. When you cook an egg some of that water weight will evaporate.
Sorry if I am repeating myself!


I found that thread...
https://www.backyardchickens.com/threads/calculating-protein-percentages-of-eggs-and-peas.1251407/
Make it a great day!
