Breakfast is often said to be the most important meal of the day, but according to a new review out Wednesday in the BMJ, it won’t help you lose weight. The study found no good evidence that regularly eating breakfast helps us cut down on calories or avoid weight gain. More damning, it even found some evidence that skipping breakfast entirely would be better for our waistlines—although you should probably find better ways to stay fit.
There are good reasons to eat up early in the day, especially if you’re young. Research has shown that regularly eating a healthy breakfast (think fruits, veggies, and whole grains) helps kids and teens develop normally and stay sharp in school. Many public health organizations and doctors have similarly recommended adding a healthy breakfast to your routine as a way to prevent obesity or promote weight loss.
The theory behind this advice is simple: Eating early will speed up your metabolism and keep you from feeling extra hungry and overeating at later meals. There is evidence of this theory from some studies. These studies are usually observational, though, meaning they only look for indirect associations between two things (in this example, eating or skipping breakfast and weight loss or less obesity) in a decent-sized group of people. But in the past few years, some randomized and controlled trials—often considered the gold standard of evidence—have failed to find the same link.
“The problem is that those who eat breakfast tend to be different to those who don’t. Therefore, the problem with observational studies is that it may not be the breakfast eating that is good but rather the individual’s wider healthy lifestyle and food choices that result in the benefits on weight,” senior author Flavia Cicuttini, an epidemiologist at Monash University in Australia, told Gizmodo via email.
Cicuttini and her team decided to round up and analyze as many relevant clinical trials on the topic as they could find to help settle the question, something scientists call a meta-analysis. They looked at 13 trials, conducted in the U.S., UK, and Japan between 1992 to 2016, that collectively studied more than 500 adults of varying weight and body mass index. Some of the trials tested if adding or skipping breakfast could affect weight; others looked at whether breakfast would affect a person’s total calories in a day.
“We found that those who ate breakfast tended to eat about 260 extra calories per day more and on average gain 0.44 kilograms [roughly a pound],” said Cicuttini. “Importantly there was no evidence for improved metabolism in those who ate breakfast or that they were less likely to overeat later in the day.”
This pattern held up regardless of where the studies took place or how much the volunteers weighed.
The authors did add their findings shouldn’t be taken as definitive. For one, the overall quality of the evidence they reviewed was deemed to be low. Few of the studies blinded the volunteers, meaning they knew if they were eating breakfast or not. Granted, that might be hard to practically hide from someone, but studies also rarely blinded the researchers who had to measure and calculate the results they got from the volunteers—another science no-no. All of the studies, the team found, also had a high or unclear risk of bias.
The authors say it’ll take more research, preferably from large, high-quality trials, to be completely sure of anything. But in the meantime, Cicuttini said, there are clear takeaways the average person should have from their research.
“The key message is that if a person likes to eat breakfast that is fine,” she said. “However, there is no evidence that we should be encouraging people to change their eating pattern to include breakfast in order to prevent weight gain or obesity... It may do the opposite!”