The study below points to the idea that in a state of protein deficiency, this may influence the body towards greater consumption in order to fill the void. However, the structure of a westernized diet of carbohydrate rich foods can be counter productive (1). By replacing protein with carbohydrates alone, the body will tend to still eat more when the carbohydrate is high on the glycemic index (2). A higher protein breakfast has been shown to have an impact on glycemic variability (3) that can likely play into satiety throughout the day.
From this stand point, it is natural to conclude protein from eggs or lean meat for breakfast will suffice, which are excellent sources. This assumption is correct, however, there are two reasons why I prefer whey as a source: convenience, and price. The only other problem that people will have is finding a good source of whey that is altered(4). This is why I am recommending Earth Fed Muscle. http://www.earthfedmuscle.com// Not only are they are a reliable source, they care about their product.