"Are Avocados Fattening?"
What are the effects of avocado on metabolic syndrome,
which is a clustering of risk factors: high blood sugars, high blood triglycerides,
high blood pressure, and obesity that sets you up for diabetes and heart disease?
Avocado consumption is associated with not only better diet quality
and nutrient intake, but lower metabolic syndrome risk.
Avocado eaters only had half the odds of metabolic syndrome.
The study was funded by the Avocado Board, though,
so it's especially important to dig into how they designed it.
The data came from a snapshot-in-time cross-sectional survey
of about 17,500 people, who were asked if they had eaten any avocado
in the last 24 hours on two separate occasions.
Two percent said yes, and so the health stats from the few hundred folks
who reported they had eaten avocado recently were compared
to the health stats of the 17,000 individuals who said they had not.
And the proportion of people with metabolic syndrome
among the avocado group was only half that of
the non-avocado group. And they were slimmer, too,
significantly trimmer waists and lower body weight
despite no significant difference in caloric intake.
The authors treat this as some kind of mystery, but it was
just how many calories they ate on the day of the surveys, not over time,
though, I mean, you could see how people could lose weight.
Avocados, like all fruits, are mostly water,
along with fiber, which has no calories at all.
So a schmear of cream cheese on a bagel
would add more than twice as many calories
as the same schmear of avocado, but that brings up an important point.
Maybe those who eat avocados just tend to have healthier diets in general.
I mean, if you're spreading avocado on your toast,
maybe you're spreading less butter or margarine.
And indeed, avocado eaters also reported eating more fruits
and vegetables in general, and less added sugar.
No wonder they were healthier. It's right there in the title:
"Avocado consumption is associated with better diet quality."
So this is, in effect, saying that those who eat healthier are slimmer
and have a lower risk of disease. Well, duh.
And this could be in part because they were eating avocados,
have nothing to do with the avocados, or even be in spite of the avocados.
You don't know until you put it to the test.
What is the effect of avocados on body weight?
It's evidently evident from some study that an avocado extract
caused a reduction in body weight, but the study was on the body weight of rats,
and it was an avocado leaf extract.
Who eats avocado leaves? Well, evidently in Nigeria
an herbal remedy for high blood pressure is avocado leaf tea.
Oh, does it actually work?
Researchers tried it out on some hypertensive patients,
and it seems avocado leaves
"have a toxic effect on the liver that could cause liver damage."
So yeah, I guess technically it can be used in the treatment of hypertension,
but only if you don't care about the pesky hepatotoxicity.
No, thanks.
Are there no human studies on avocado fruits and body weight?
Well, evidently there was a study 50 years ago back in 1960
on avocados and cholesterol, in which the subjects
did not gain weight when avocados were added to their diet.
I did find a reference to the study in the California Avocado Society Yearbook
lamenting how difficult it is to "impress the housewife"
as to all the unnamed benefits of avocados.
Now it's true that body weights didn't change much after avocado feeding,
but they didn't just add avocados to their diet;
they substituted avocado for some of the animal fat they were eating.
So they like swapped out lard for avocado;
no wonder there was no weight gain.
Now in one subject they did just add the avocado.
Started out at 154 pounds,
and after three weeks of added avocado, no weight gain.
OK, so maybe avocado is so satiating, so satisfying,
that when you add it to your diet,
you just naturally end up eating less of other stuff.
But you don't really know until you put it to the test.
A randomized, controlled study to evaluate the effect
of Hass avocado intake on satiety and subsequent caloric intake.
Adding half an avocado to a lunch meal
did improve satisfaction and reduce hunger.
But duh, yeah, they just added an extra 112 calories of food;
of course they felt less hungry.
The question is, did they feel so much less hungry
that during supper they ate 112 calories less to compensate?
And the answer is no.
In fact, they didn't eat significantly less at all.
What about over time?
This study added an entire avocado to people's daily diets for 6 weeks
and found no significant weight gain,
so they triumphantly claimed to dispel the myth that avocados are fattening.
But this was like the lard study.
Yeah, they added an avocado, but they removed the same amount of fat
in the form of margarine, mayonnaise, and oil.
Now, this is a healthy swap—
I mean removing junk and adding nutrition, adding fiber—
but if the calories in and out are the same,
then no wonder no difference in body weight.
In fact, one could have just as well concluded
that avocados are as fattening as margarine, mayonnaise, and oil,
if you're eating the same amount of fat.
Maybe the housewife was unimpressed because
she just knew a little something about proper study design.