Here's a great piece by Anahad O'Connor that looks at the dozens of studies that are supposed to link the act of eating breakfast with weight loss — and the problems that very quickly arise when you look at them closely. The biggest issue: Most of the advice you get telling you to eat breakfast if you want to lose weight is based on observational studies — large collections of information about people's lives and health that scientists then comb through looking for correlations. Like any correlation, those associations should be thought of as jumping-off points for more research, not proof of how you should live your life. With breakfast and weight loss, the truth seems to be that the two things may not be connected at all. For every study that shows them inextricably linked, another found no relationship at all ... or even an inverse relationship, where skipping breakfast led to weight loss.