You鈥檙e wrong about breakfast. And so is everyone else. Despite years of hype, two new studies point to a startling conclusion: skipping breakfast doesn鈥檛 necessarily lead to weight gain. Nor does eating breakfast boost your metabolism, suppress appetite, or reduce overeating later in the day. But it still might be one of the most important meals of the day (more on that later).
鈥淥ur findings are a bit of a reality check,鈥 said nutritionist Emily Dhurandhar, an assistant professor in the (UAB), lead author of one of the studies. 鈥淚t鈥檚 a broader question we鈥檙e trying to answer. As a message interpreted by the general public, just recommending people eat breakfast is not sufficient.鈥
While years of observational research have shown associations between eating breakfast and being leaner, none of the studies reach the gold-standard level of evidence of showing causation鈥攔andomized controlled trials鈥攖o show that breakfast was indeed responsible for weight loss, says James O. Hill, a professor of pediatrics and medicine at the , and co-author on Dhurandhar鈥檚 .
At last, gold-standard research on breakfast has arrived. And the findings subvert years of nutritional advice while highlighting one often underestimated and under-hyped benefit of the morning meal. Dhurandhar鈥檚 trial randomized 309 overweight or obese adults who were given healthy eating advice to two groups. One group ate breakfast and the other skipped. Both groups lost a little weight, but there was no greater weight loss in the breakfast eaters as compared to the skippers. The researchers are careful to note that the study was not a controlled feeding trial and the subjects were not told what to eat at breakfast.
Another , led by James Betts, a senior lecturer in nutrition from the University of Bath, randomized 33 lean adults to either eat or skip breakfast for six weeks. The study found no appreciable difference in metabolic or cardiovascular health markers. 鈥淚t is commonly stated that breakfast kick-starts metabolism and/or reduces snacking, etc. We saw little or no evidence of these things,鈥 Betts said.
Insofar as testing has gone, the evidence hasn鈥檛 boded well for breakfast. But it wasn鈥檛 all bad news, Betts said. His study was also one of the first to measure how a feeding pattern influenced physical activity levels throughout the day using combined heart rate and accelerometry (think: sophisticated wearable tech, not just pedometers).
Betts sums up the results: 鈥淪pecifically, the breakfast group was much more physically active than the fasting group, with significant differences particularly noted during light-intensity activities during the morning.鈥
In this case, this was causal evidence (not just correlation) that breakfast gets people moving鈥攇ood reason to keep enjoying the most important meal of the day.
Our near-sacred regard for 鈥渄on鈥檛 skip breakfast鈥 is one of the most fundamental but oversold nutritional guidelines, and as we鈥檙e now discovering, there are plenty of other flawed recommendations in the nutrition world. So the problem isn鈥檛 with breakfast. It鈥檚 with a failure of skepticism, says the study鈥檚 senior investigator whose began the attack on the conventional thinking, David Allison, director of UAB鈥檚 .
鈥淭his goes back to the idea that we need to be more skeptical鈥攚e as scientists, as journalists, we as public health officials,鈥 Allison said. 鈥淭hese platitudes sound good. You tend to believe them, but some might not be true.鈥
The perpetuation of pro-breakfast bias could be said to come in part by lobbying and funding of research by food companies keen on selling breakfast cereals and packaged breakfast foods. But diet myths are also often spread through shoddy reporting and writing. And they frequently come from public figures at the intersection of health and pop-culture. Take this line from the polarizing . His site reads, 鈥淭he fact is, when you鈥檙e trying to lose body fat, you can鈥檛 skip breakfast鈥︹ and 鈥淏oost your metabolic rate by 25%.鈥
Don鈥檛 trust Dr. Oz? How about this line from the Mayo Clinic鈥檚 site, 鈥淚n fact, skipping breakfast actually increases your risk of obesity鈥 or this quote from a researcher on Yahoo! Health, 鈥淪kipping breakfast may lead to one or more risk factors, including obesity, high blood pressure, high cholesterol and diabetes, which may in turn lead to a heart attack over time.鈥
Not only is the Internet rife with this kind of language, but so too is the scientific literature, Allison points out. And it鈥檚 not always in research that has received food industry funding, he says. There鈥檚 what he calls 鈥渨hite hat bias鈥 largely found in observational or short-term trials that also suggest breakfast produces beneficial effects on metabolism and satiety. But, once again, these types of studies cannot demonstrate causation. These limitations are rarely addressed in the research or in the media hype. Plus, not all breakfasts should be considered equal; the timing and nutritional content (think: sugary cereal versus eggs) are both key.
鈥淚t鈥檚 tempting to assume that if something shows promise in a short-term study, or if it has some aspect on insulin or fat metabolism, that we can extrapolate from these. But I think that it鈥檚 important that we test these things,鈥 Dhurandhar said.
If there鈥檚 one underlying message these researchers are giving, it鈥檚 just this: beware oft-repeated diet advice not rooted in evidence. Additional vague platitudes that perhaps deserve equal attention are 鈥渆at everything in moderation鈥 and 鈥渆at only when you鈥檙e hungry.鈥
As made clear with the rigorously designed tests on breakfast, our presumptions don鈥檛 always hold true. But breakfast now has one new thing going for it: increasing physical activity.
鈥淲hether or not you have breakfast can dictate how much activity you engage in, which directly impacts energy balance but also holds implications for health via the independent benefits of living a more active lifestyle,鈥 Betts said.