What a Keto Diet Cheat Meal Might Do to Your Body

After a week of eating low-carb and high-fat, reintroducing carbs to the diet might negatively affect your blood vessels.

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Apr 5 2019, 5:35pm

Jesse Morrow / Stocksy

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Taking a sudden break from your keto diet might negatively impact your blood vessels

During a cheat meal, you throw your food rules out the window and indulge. For people on the keto diet, this might mean filling a plate with carbohydrates, which the body metabolizes as glucose. A keto diet is rich in fats and proteins, and a very low amounts of carbohydrates— the goal is to cause the body to go into a state called ketosis, where it burns fat as its energy source, instead of glucose.

In a new paper published in Nutrients, researchers were interested to see what would happen when people on a keto-like diet were reintroduced to the carb-rich foods they had been avoiding (like during a cheat meal).

Impaired glucose tolerance and spikes in blood sugar are associated with cardiovascular disease, says Jonathan Little, an exercise and diabetes researcher at The University of British Columbia, and senior author of the study. Because of that association, he and his colleagues looked at people’s blood vessels when they were given glucose after spending a week on a low-carb, high-fat diet.

Little tells me that they didn’t measure ketones in their subjects to definitively tell whether they were in ketosis in the study. But since all the foods were provided, and people ate less than 50g of carbs per day, it was “like ketogenic.”

After one week on this diet, they gave nine healthy males 75 grams of glucose, which is about the same amount of glucose as a large bottle soda or a plate of fries, a press release says. They saw a spike in glucose, which was to be expected, but also saw evidence in their subjects of blood vessel wall damage.

The markers they saw are called “endothelial microparticles” or “endothelial microvesicles,” which are small pieces of the cells that line the surface of the vessel. They are released when the cells are inflamed or damaged. These microparticles weren’t present when glucose was given before the low carb high fat diet. “If endothelial microparticles go up in your blood it tells us that the endothelial cells appeared to be unhappy,” Little says.

Cody Durrer, first author on the paper, says that their findings could suggest that following a keto diet might make you more intolerant to carbohydrates and predispose you to blood vessel damage if you suddenly gorge on carbs.

"My concern is that many of the people going on a keto diet—whether it's to lose weight, to treat Type 2 diabetes, or some other health reason—may be undoing some of the positive impacts on their blood vessels if they suddenly blast them with glucose," Durrer says in the release. "Especially if these people are at a higher risk for cardiovascular disease in the first place."

The study also found, though, that the increase in these markers of damage was transient, and returned to baseline measurements within two hours. “It is possible that this could be a normal adaptive response that helps kickstart the body, or ‘wake it up,’ to the reintroduction of carbohydrates after not consuming much of them for a week,” Little explains.

For now, these effects need to be studied in a larger sample size. Little says that if a keto diet is helping you achieve greater health goals, and a cheat meal helps you sustain those goals, then he still thinks the potential benefits might outweigh any potential risks.

Your brain processes metaphors literally

We often speak in metaphors, where words don’t literally mean what we say. She grasped the idea, is different than grasping a fork; a rough day is different than a rough towel; a sweet boy is not the same as a sweet cupcake.

But our brains might process metaphors and their literal counterparts in very similar ways—previous studies have suggested that our understanding of metaphors may be rooted in their physical meanings. There’s some evidence that when we hear phrases like she grasped the idea, the parts of our brain involved with sensory-motor function (the other grasping) are active too. Or that tactile and taste metaphors (rough and sweet) also activate sensory regions of the brain.

In a new study in Brain Research, researchers looked at when exactly these brain activations of the literal interpretations of metaphors took place. Were metaphors first being processed in the literal sense, and then metaphorically? This could help answer an outstanding question: Is the literal understanding necessary to understand a metaphor at all?


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The study looked at when different brain regions were active when people were given three sentences, two with a shared metaphorical word, and one without. For example: The bodyguard bent the rod, the church bent the rules, and the church altered the rules.

When people saw the word bent they had similar response in the brain each time, even when bent was being used metaphorically. The sensory-motor areas of the brain were active right away, in around 200 milliseconds.

“Metaphoric phrases behaved more like concrete literal phrases in that both rapidly activated sensor-motor systems,” says Vicky Lai, an assistant professor of psychology and cognitive science at The University of Arizona, and the paper’s first author. She says their findings still don’t fully reveal how we understand metaphors, but they let us know that the literal understanding is probably very important to comprehending the metaphor overall.

Moreover, Lai says that it furthers her work on how metaphors might benefit learning and emotion. For learning, one of her other metaphor projects asks if students can more easily learn science concepts when there are metaphorical explanations. Another asks people to use metaphors to think about past sad experiences, and see if it helps them feel better.

Until we know more about how to use metaphors for our benefit, they can reveal how speakers between cultures organize their conceptual categories, she says.

“For example, in Mandarin Chinese you can say ‘stir-frying the stock market,’” she says. “Which means to manipulate the stock market for one's benefit.”

Mice grew taste buds in their lungs after having the flu

Despite getting my flu shot, I still got the flu this year, and spent about a week not moving farther than from my bedroom to my couch. But for some people, the effects of the flu linger way beyond a week, and they have continuing problems with their lungs.

In a new study in the American Journal of Physiology Lung Cellular and Molecular Physiology, researchers infected mice with the flu and then examined their lungs, to see how their lungs recovered.

“A severe case of the flu can actually reshape the architecture of [the rodents’]their lungs and forever compromise their respiratory function,” says a press release from the University of Pennsylvania's School of Veterinary Medicine.

To the researcher’s surprise, they found cells in the lungs that are nearly the same as taste bud cells, called tuft cells, or solitary chemosensory cells.

These are the same kinds of cells that detect bitterness, and “when the researchers stimulated the out-of-place cells with bitter compounds, they went wild, growing and triggering an inflammatory response,” Live Science reported.

“It was just really weird to see, because these cells are not in the lung at baseline,” senior author and biologist at Penn’s School of Veterinary Medicine, Andrew E. Vaughan, says in the statement. “The closest they are normally is in the trachea.”

This study was done in mice, so the next step is to see if humans also have these kinds of cells in their lungs after getting the flu. If they do, it could explain why children who get respiratory infections are predisposed to developing asthma.

Your weekly science and health reads

I am not always very attached to being alive. By Anna Borges in The Outline.
A very moving, personal piece about a little-talked about subject: chronic, passive suicidal ideation.

Is your wellness practice just a diet in disguise? By Melissa A. Fabello in Healthyish.
A reminder to examine the everyday “wellness” habits we pick up, and ask if they’re rooted in disordered eating.

The challenge of going off psychiatric drugs. By Rachel Aviv in The New Yorker.
Going off a drug, or two, or five—can be a rocky road.

Millenials are sick of drinking. By Amanda Mull in The Atlantic.
Are we quitting drinking altogether or just tired of the way it makes us feel?

How A.S.M.R. Became a Sensation. By Jamie Lauren Keiles in the New York Times Magazine
A “‘silvery sparkle’ inside the head, a euphoric ‘brain-gasm’ or a feeling like goose bumps in the scalp that faded ‘in and out in waves of heightened intensity.’”

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