"Is Breakfast the Most Important Meal for Weight Loss?"
Breakfast is widely touted as not only the most important meal of the day
in general, but specifically in relation to weight loss.
This is not just a pop culture prescription from
checkout aisle magazines,
but an idea put forward by prestigious institutions such as
Johns Hopkins, NYU, Mayo Clinic, even the United States Surgeon General.
"Want to trim your waist?" read a headline
in the American Dietetic Association.
"Try eating breakfast," referring to breakfast
as perhaps the best kept weight-trimming secret.
But is it true?
The Duke School of Medicine's health newsletter was skeptical:
"It's always been billed as the most important meal of the day—until now."
While it's widely presumed that eating breakfast protects against obesity,
the belief is held up as a poster child of biased distortion of the scientific record.
No one can argue that there isn't an association
between body weight and breakfast.
Studies have shown that obesity and breakfast skipping tend
to go together beyond a shadow of a doubt, in fact gratuitously so.
By 1998 we already had what might be considered strong evidence
of an association between breakfast skipping and obesity,
but researchers continued to repeat such studies to the point of ridiculousness.
This meta-analysis found that by 2011, the combined P value had reached 10-42.
OK, what does that mean? Why is that ridiculous?
In science, P value refers to the chance of getting a result that extreme
if in fact there really was no such effect.
How small a chance is 10-42? This is how small that number is.
In other words, the probability that the association between
obesity and breakfast skipping was just a fluke
is less than the chances of winning the lottery, not once but five times in a row,
and then subsequently getting struck and killed by lightning.
OK, so the association between breakfast skipping and obesity
is indeed beyond question. We know the association is true.
People who skip breakfast are more likely to be overweight;
that's beyond a shadow of a doubt.
The question, though, is whether that iron-clad relationship
between breakfast skipping and obesity is actually cause-and-effect.
To illustrate the difference between correlation and causation,
let me share an example of the manipulation of science
by the candy industry.
The National Confectioner's Association had the gall
to warn parents that restricting candy may make their children fat.
They justify this outlandish claim with this study, that they funded of course,
that showed that candy consuming children and adolescents
were significantly less likely to be overweight and obese.
The industry-funded researchers go on to imply that this exonerates candy.
But what's more likely?
That cutting down on candy led to obesity,
or rather that obesity led to the cutting down on candy?
In other words, the lower candy consumption may reflect
the consequences of obesity, not the cause,
as parents of obese children try to restrict treats.
Similarly, the finding that those who skip breakfast tend to be heavier
is equivalent to saying those who are heavier tend to skip breakfast.
Doesn't it seem to be more likely that overweight individuals
might just be skipping breakfast in an effort to eat less,
rather than eating fewer meals somehow leading to weight gain?
Now it's possible that skipping breakfast could slow your metabolism
or cause you to overeat so much later in the day that you'd gain weight,
but you can't know for sure until you put it to the test.
Sometimes, randomized controlled trials are infeasible, impossible, or unethical.
To test to see if parachutes save lives,
you can't exactly boot half the people off a plane without them.
But you could easily randomize people to eat breakfast or not and just see what happens.
And it turns out eating breakfast does not seem to affect your metabolism rate
or sufficiently suppress your appetite.
Most studies—95%—found that eating breakfast tends to lead
to the same or greater caloric intake over the day.
Even when people ate more at lunch after skipping breakfast,
they didn't tend to eat an entire breakfast worth of calories more,
and so ended up eating fewer calories overall.
For example, feed people about a 500-calorie breakfast,
and at lunch they may eat about 150 calories less
than those randomized to skip breakfast, but they would still end up
with about a 350-calorie surplus over the breakfast skippers.
Does this then translate into weight gain over time?
Researchers at Brigham Young University randomized 49 women who habitually
skipped breakfast to either start eating breakfast or continue skipping.
If breakfast somehow magically leads to weight loss,
then the newly eating breakfast group should benefit.
But no, compared to those who continued to skip breakfast,
adding the extra meal led to hundreds more daily calories consumed
and nearly a half pound of weight gain a week.
If you already eat breakfast and start skipping it, will you lose weight?
We'll find out next.