The media can just never get enough of these ‘doing XX can kill you’ headlines, so it’s up to me to come behind them and clean up the mess. The recent research on eggs is one example, and the latest study on how skipping breakfast can cause you to die of a cardiovascular event, is another.
The New York Times, CNN, USA Today, and every other major media outlet has jumped on this study with headlines like ‘Skipping breakfast linked to higher risk of heart disease death!’.
Maybe it’s me, but any time a headline has the word ‘death’ in it, I just can’t look away, and I’m assuming most people can’t, either.
So does skipping breakfast really mean we’re going to die from heart disease?
Let’s take a look at what the study said.
This is what we know about breakfast
When it comes to breakfast, the research is consistent: in that, I mean consistently undecided.
Earlier in the year, a study came out that concluded that eating breakfast could cause weight gain. Other breakfast studies in past years have come to various conclusions about whether the meal is important for health and learning, but the research has always been inconclusive and the studies contradictory of each other’s findings. Moreover, many of the studies had questionable methodology, and many of them have been sponsored by breakfast food companies like Quaker or Kelloggs. That’s not a deal breaker, but we do need to note that many (okay, most) studies sponsored by food companies tend to come out in favor of those companies.
What Did This Study Find About Breakfasts?
Researchers used NHANES III data from 6550 participants between1988 to 1994. NHANES is the National Health and Nutrition Examination Survey, during which the CDC uses data collected from a large cohort of people in the US to assess the health and nutritional status of adults and children. This breakfast study gleaned all of its data from the data that was already collected from NHANES.
They were asked how often they ate breakfast, and chose from the following options:
This breakfast study adjusted for age, sex, race/ethnicity, socioeconomic status, dietary and lifestyle factors, body mass index, and cardiovascular risk factors.
Follow-up occurred between 17 and 23 years after the data was taken from participants.
Out of the 6550 people included in this breakfast study, 619 had died from cardiovascular disease. When the study authors crunched the numbers, they concluded:
“In a nationally representative cohort with 17 to 23 years of follow-up, skipping breakfast was associated with a significantly 87% increased risk of mortality from cardiovascular disease. Our study supports the benefits of eating breakfast in promoting cardiovascular health.”
Okay, so this is where the headlines came from.
Except…that’s only half the story! You knew I was going to say that, didn’t you!
So, what’s the other half? This:
First off, frequency of breakfast eating was reported only once – during an in-house interview at the beginning of NHANES III.
I think it’s pretty important to consider that in the 18-23 years between that initial interview and the follow up, peoples’ breakfast habits could very well have changed. Call me crazy, but 23 years ago my breakfast habits were pretty darn different from what they are now.
Participants also weren’t asked what they ate for breakfast, how they defined ‘breakfast’, or when they ate breakfast. They were just asked how often they ate it. All of this is very important information that we aren’t getting!
What if the breakfast eaters were eating sausages and Froot Loops every day for their morning meal? Wouldn’t that be good to know?
Of course it would.
And although study authors said they controlled for lifestyle and activity factors, they state in the study that participants who never consumed breakfast were more likely to be non-Hispanic black, former smokers, heavy drinkers, unmarried, physically inactive, and with less family income, lower total energy intake, and poorer dietary quality, when compared with those who regularly ate breakfast.
And this: Participants who never consumed breakfast were more likely to have obesity, and higher total blood cholesterol level than those who consumed breakfast regularly.
All of those things increase risk for cardiovascular disease, and they were controlled for in the study. Still, the truth is that you can’t control for everything; especially when the ‘never eat breakfast’ group is basically a ticking cardiovascular time bomb.
Does that mean we need to throw every study into the garbage because it fails to control for every little thing? No, but we need to take that into account when interpreting the results.
Absolute versus relative risk
The study found that compared to people who ate breakfast, people who didn’t eat breakfast at all were 87% more likely to die of heart disease.
That sounds really bad, doesn’t it? 87% is a really high number! I wouldn’t go to Vegas with those odds!
Except, 87% is the relative risk. That’s the probability of an outcome in a group.
The absolute risk – meaning, the size of your own risk – of having a cardiovascular event directly related to skipping breakfast is actually really, really low. Like, under 1%.
Media usually reports relative risk of something because it sounds so much more ominous, and ominous = more clicks. The truth is, that the risk for individuals is so much smaller.
The study also showed that all-cause mortality in breakfast skippers – meaning, chance of dying from anything – was barely a blip on the radar. If breakfast is so important for prevention of death, all-cause mortality would be significantly elevated. It’s not.
Want to know more about risk? This article about relative versus absolute risk is a must-read.
So, Is Skipping Breakfast Bad For You?
This study, while great in some respects – it used a nationally representative sample, and had a lot of participants – was faulty AF.
The breakfast skippers were the picture of cardiovascular risk, no matter if factors were controlled for or not.
The study never defined ‘breakfast’ or took into consideration what people ate.
Data was based off of one single interview done 17-23 years prior to follow up.
The absolute risk was almost nothing.
I’m going to say it once more for all of you in the back:
CORRELATION DOES NOT EQUAL CAUSATION!
So, as you were.
If you don’t eat breakfast, you don’t need to start because of this study.
If you do eat breakfast, you don’t need to continue because of this study.