The U.S., being a very fat nation, is almost as obsessed with weight loss “tricks” as it is with stuffing calorie-dense “food” into its collective gaping maw. Though diet fads come and go, one old adage has persisted: Dieters who eat breakfast tend to be skinnier. Now, researchers from the University of Alabama at Birmingham (who apparently decided to look into the whole “correlation vs. causation” thing) have found something shocking: When it comes to losing weight, eating (or skipping) breakfast has approximately zero effect.

In a first of its kind study published in the American Journal of Clinical Nutrition, researchers set out to measure the effect of recommendations to skip breakfast (as well as changing one’s breakfast habits) on weight loss. The 16-week trial enrolled 309 otherwise healthy overweight and obese adults, 20-65 years old. While the control group was only provided nutrition information, experimental groups were instructed to either eat or skip the day’s first meal. In the end, there was no measurable effect on weight loss based on experimentation.

“Previous studies have mostly demonstrated correlation, but not necessarily causation,” said lead author Emily Dhurandhar, Ph.D. “In contrast, we used a large, randomized controlled trial to examine whether or not breakfast recommendations have a causative effect on weight loss, with weight change as our primary outcome.”

Though disconcerting for breakfast-for-weight-loss Zionists, the researchers believe the findings are actually a good thing.

“Now that we know the general recommendation of ‘eat breakfast every day’ has no differential impact on weight loss, we can move forward with studying other techniques for improved effectiveness,” Dhurandhar said. “We should try to understand why eating or skipping breakfast did not influence weight loss, despite evidence that breakfast may influence appetite and metabolism.”

To their credit, the researchers do point out several limitations to the study. For one, focusing on weight loss as the final outcome ignores more nuanced measures like body fat or metabolism, to say nothing of appetite. Also, though 16 weeks is longer than most studies like it, there’s still the possibility that trends would emerge from an even longer study. Finally, since there was no measure of the type of foods breakfast eaters consumed, there’s no telling what (if any) foods might be more helpful than others.

Still, if nothing else, the researchers see the study as a perfect example of why it pays to be skeptical.

“The field of obesity and weight loss is full of commonly held beliefs that have not been subjected to rigorous testing; we have now found that one such belief does not seem to hold up when tested,” said David Allison, Ph.D., director of the UAB Nutrition Obesity Research Center and senior investigator on the project. “This should be a wake-up call for all of us to always ask for evidence about the recommendations we hear so widely offered.”