Is Breakfast the Most Important Meal for Weight Loss?

“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
for 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, and 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, the P value refers to the chance
of getting a result that extreme if there
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 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, which 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 and tend to skip breakfast. Doesn’t it seem to be more likely
that overweight individuals might just be skipping breakfast
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 that 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.