"The women who consumed eggs as part of their diet plan lost significantly more weight, had greater reductions in waist circumference and reported significantly higher energy levels."
Study finds weight loss greater with eggs, even when all else is equal
Specifically, the study found that overweight women who ate two eggs for breakfast at least five days a week for 8 weeks (as part of a low-fat diet with a 1,000 calorie reduction):

It has been proven that the increase of high quality protein in the diet with the inclusion of eggs produces a metabolic advantage to the body. This is because of the presence of a branched chain amino acid, leucine, which is found in eggs and lean meat. In fact, it is said that the amount of eggs that is consumed, and the time of the day that it is consumed are important factors to be reckoned with in weight loss.