They found people who regularly ate breakfast lowered their chances of developing type 2 diabetes by over 30 percent. They also found that people decreased their risk of developing type 2 diabetes by 5 percent for each day of the week they ate breakfast. Previous research in nutrition has shown that skipping even a single breakfast can cause insulin resistance for the next meal.
In another study, where subjects were trying to lose weight by reducing calories, researchers found people who usually skipped breakfast and then started eating breakfast lost more weight than those who ate the same amount of calories in just two meals. However, if someone normally ate breakfast, they lost more weight if they then skipped it during the experiment. They also found that people who ate breakfast were able to reduce snacking.
Not all breakfasts are created equal, though, and what we eat matters. Another study compared eating breakfasts either high in carbohydrates or high in protein. They found eating a breakfast high in protein increased satiety by decreasing the amount of hormones that cause hunger.
Mekary RA, Giovannucci E, Willett WC, van Dam RM, Hu FB. Eating patterns and type 2 diabetes risk in men: breakfast omission, eating frequency, and snacking. Am J Clin Nutr. 2012 May;95(5):1182-9. Epub 2012 Mar 28. PubMed PMID: 22456660; PubMed Central PMCID: PMC3325839.