Can "low fat" eggs have an impact on meringue formation? Yesterday I tried making a meringue-based dessert with a recipe I've used successfully a few times before, which calls for 6 egg whites and 1.5 cups of sugar. I made sure to have no egg yolk with the whites, I used a stainless steel bowl and mixer attachment, the eggs were at room temperature - everything to my knowledge that should result in perfect peaks after mixing thoroughly. 

After getting everything together though, my first batch of meringue never got past a marshmallow fluff-like thick but somewhat runny consistency. I tried again two more times being very careful to make sure everything was perfectly clean, and ended up with the same results each time. 

At this point while cleaning up, I notice the packaging for the eggs stating that they have "25% less saturated fat than regular eggs" eggs, due to a special diet.

Could lower than average fat content in eggs affect getting stiff peaks from a meringue?
I would look at the age of the eggs - take a look at the sell by date on the carton.

If the eggs are fresh it takes more whisking to get it to stiffen up, but once there it will hold longer.

If the eggs are older it doesn't take much whisking to get stiff, but you need to not let it sit out for too long or it will get runny and collapse.

You might also look at the temperature. If the eggs were room temp they would act more like older eggs. If the eggs were cold from the fridge they would act more like newer eggs. 

Sounds like you did a good job of checking for a clean bowl and no yolks. Buying new eggs that are fresh, cold and not served a special low fat diet will probably do the trick.

Hope that is helpful.