fitness · weight loss

Cutting off our noses in service of our waistlines

As long as there is a wave of fat phobia and moral panic over body weight out there in the science journalism world, we will never be at a loss for something to write about here at Fit is a Feminist Issue.

Here’s the latest headline:

News headline: Just smelling food can make you fat, UC Berkeley study says
News headline: Just smelling food can make you fat, UC Berkeley study says

Is this true?

Graphic saying NO, of course not!

So what’s the deal here?  Well…

Graphic saying "It's complicated".

The news article (found here) summarizes the study below:

…a sense of smell can influence the brain’s decision to burn fat or store it in the body — or a least the bodies of mice.

Researchers Andrew Dillin and Celine Riera studied three groups of mice — normal mice, “super-smellers” and ones without a sense of smell — and saw a direct correlation between their ability to smell and how much weight they gained from a high-fat, “Burger King diet,” Dillin said.

Each mouse ate the same amount of food, but those with a super sense of smell gained the most weight. 

The normal mice ballooned, too — up to 100 percent from the weight they were when the research started.

But the mice who couldn’t smell anything gained only 10 percent of their weight. Obese mice who had their sense of smell wiped out slimmed down to the size of normal counterparts without a change in diet.

Riera said the study, which was published this month in the journal Cell Metabolism, reveals that outside influences such as smell can affect the brain’s functions related to appetite and metabolism.

Okay, that’s fairly interesting.  Looking at the actual article, we see that what it is really about is:

[discovery of] a new bidirectional function for the olfactory system in controlling energy homeostasis in response to sensory and hormonal signals.

That is, Riera et al. found an intriguing new piece of the puzzle of how olfactory (sense of smell) functions interact with the hypothalamus in metabolism regulation.

But it ends with a bang:

the potential of modulating olfactory signals in the context of the metabolic syndrome or diabetes is attractive. The data presented here show that even relatively short-term loss of smell improves metabolic health and weight loss, despite the negative consequences of being on a [high-fat] diet.

Whoa. Hold on a minute.  It sounds like they are suggesting that a plausible treatment for humans (that is, us) in service of weight loss would be to wipe out our sense of smell.  Is that what they’re saying? Well, yeah.

And the news article gleefully reports this:

Using the study’s methods in humans could be possible.

After eating, a person’s sense of smell decreases. So, if a person was eating with a lessened sense of smell, the brain could be tricked into thinking it’s already been fed and choose to burn the calories instead of store them, Riera said.

People struggling with obesity could have their sense of smell wiped out or temporarily reduced to help them control cravings and burn calories and fat faster.

But the article and researchers acknowledge that this “treatment” comes with risks.

Ya think?

Loss of sense of smell is common in chemotherapy, and occurs in a number of diseases and in the course of aging.  This results not only in weight loss but also nutritional deficiencies and other health problems.  In short, it’s not good.

And, it turns out, this is also true:

The mice in the study who lost their sense of smell also saw a significant increase in the hormone noradrenaline — a stress response from the nervous system that can lead to a heart attack if levels are too high.

So let me get this straight:  loss (even temporary) of someone’s sense of smell is associated with adverse health outcomes, including increased risk of heart attack.  And yet this is being considered for humans?

Yes, apparently:

“Maybe once a year you block your sense of smell for a while and then you lose the weight from the year and do it all over again,” Dillin said. “We don’t know yet. There’s a lot we still need to do.”

Yes, there’s a lot you need to do.  Like read up on the literature on the adverse health and other effects of yo-yo weight changes.  And while you’re at it, maybe read a medical ethics book too. And medical history.

My apologies for the snark, but this extreme approach to medical treatments for body weight change and maintenance is not new.  Some of you may recall that in the 70s and 80s, jaw wiring was an approved medical treatment for weight loss.

A picture of a person's mouth, open and showing upper and lower teeth on the side wired together with orthodontia
A picture of a person’s mouth, open and showing upper and lower teeth on the side wired together with orthodontia.

This was not a fringe thing.  Here’s an article in the prestigious medical journal The Lancet from 1977, studying the effects of jaw wiring in patients.  They note that patients lost weight, although

Two-thirds of the patients, however, regained some weight after the wires were removed.

Of course they did–  they were physically unable to eat solid food by the mechanical devices that clamped their jaws together.  They were literally starved.

This form of treatment has fallen out of favor (thank goodness), but hasn’t disappeared completely.  Here’s a current orthodontist website advertising this treatment, and encouraging other dental professionals to get on the jaw wiring bandwagon.

So, wrapping up:  while it is interesting to learn new features of the complicated interactive metabolic processes of mice, and see to what extent those processes are also present in humans, we need to take a big long pause before considering any treatment applications, for a host of reasons, both medical and ethical.

The nose knows a lot; let’s keep smelling.

A picture of a person's nose, smelling a slice of pink grapefruit.
A picture of a person’s nose, smelling a slice of pink grapefruit.

 

 

 

 

 

 

 

4 thoughts on “Cutting off our noses in service of our waistlines

  1. social media is full of blah.. only those who knows themselves well cannot be affected by it. I don’t know anymore which health article is telling the truth or just marketing strategy.. tsk2

  2. Part of enjoying food is smelling it! I think people are taking weight loss a little bit too seriously! I know we have a obesity epidemic but food is meant to be enjoyed and it is such a large part of life!

  3. I don’t have a sense of smell…and I’ve always struggled with my weight. One of the things that happens for me with food is that I turn to very salty, sweet or spicy foods because I don’t experience the nuances of flavour. I can taste some sweetness from a strawberry but not how it actually tastes- so often highly flavoured synthetic foods attract me just to get the illusion of some flavour in my life. I wish it were true that having no sense of smell helped with weight loss- and maybe it’s just me…
    Thanks!

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