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  • I'm going to guess that you've been on the internet before, and thus you've seen

  • plenty of ads for treatments that supposedly help you lose weight, “using one weird trick.”

  • Or you might have seen recent news about research claiming to have discovered what's been

  • described asexercise in a pill.”

  • Sign me up!

  • If those things really worked, I'd be speaking for everybody when I said, SHUT UP AND TAKE

  • MY MONEY!

  • Unfortunately, there's very little scientific evidence that any drug will make you lose

  • weight in a significant amount, safely and healthily.

  • However!

  • There really are some promising treatments in development right now that do at least

  • SOMETHING to help people lose weight, based on new insights into how your body absorbs

  • nutrients, and uses energy.

  • So sit down, enjoy your little bacon sandwich there, while we walk you through the facts

  • and fictions of weight-loss in a pill.

  • Let's start with what your doctor can do for real, today.

  • Because: You actually can get medications for weight loss, by prescription, and they

  • come in two basic categories: appetite suppressants and fat blockers.

  • Appetite suppressants work by blocking your body's ability re-absorb the chemical signals

  • that your brain uses, called neurotransmitters, to regulate hunger.

  • You've probably heard of a couple of these neurotransmitters -- serotonin and norepinephrine.

  • They're released by your hypothalamus to make you feel 'full.'

  • So, if a chemical can block your body's ability to reabsorb those chemicals, you would

  • feel more full, and eat less.

  • Do they work?

  • Well, sort of.

  • And only for a while.

  • When combined with diet and exercise, studies have shown that prescription appetite suppressants

  • can lead to losing around one and a half to maybe a little over 2 kilograms of extra weight.

  • But after six to eight weeks, the appetite control center in your brain adjusts to the

  • new levels of those neurotransmitters, and the weight loss benefits disappear.

  • Fat blockers work differently.

  • They inhibit an enzyme called lipase.

  • When you eat food that has fat in it, those fat molecules need to be broken down into

  • their constituent parts - glycerol and fatty acids - before they can pass through the walls

  • of your intestines.

  • That's because fat molecules are too big to pass through the membranes of your cells

  • on their own.

  • Lipases are enzymes that break down those fat molecules.

  • And in order to do that, they need to bind with them.

  • Fat-blocking drugs work by bonding with lipases, which prevents them from bonding with fat.

  • And without lipases to break it down, fat passes through your intestines and out of

  • your body without ever being absorbed.

  • So do they work?

  • Pretty well, actually.

  • Studies have shown that they stop about 30% of the fat in your food from getting taken

  • into your body.

  • And over the course of two years, people who took a fat blocking drug lost, on average,

  • about two and half kilograms more than people who didn't.

  • But there can be some serious...and kinda gross...side effects.

  • Because fat blockers keep the fat in your intestines, using the toilet can become a

  • messier, oilier business.

  • So...those are your current prescription options.

  • Then you've got your over-the-counter weight loss supplements.

  • And I'm going to be honest with you here: nearly all of these are bogus.

  • There's very little good science that suggests that any of them will help you lose weight...at

  • all.

  • According to the Office of Dietary Supplements at the National Institutes of Health, the

  • only - yes, ONLY - one of these that has stood up to reputable trials AND is legal in the

  • United States is green tea.

  • Green tea contains both caffeine and an organic compound known as catechin.

  • Separately, these two things don't contribute to any statistically significant amount of

  • weight loss, but when you put them together, they appear to act synergistically.

  • Caffeine stimulates the nervous system, which has a thermogenic effect: basically, heating

  • up your body by getting your nervous system to tell everything to go a little faster.

  • And catechins inhibit the action of lipases, which gives them a minor fat blocking effect.

  • They also stimulate the production of norepenephrine, which helps with hunger control.

  • So together, these compounds have a mild appetite suppressant effect that works the same way

  • as prescription appetite suppressants.

  • And there are apparently other mechanisms that seem to be affected by green tea as well,

  • but we don't understand them all yet.

  • So...great news, right?

  • Just start drinking lots of green tea.

  • I like green tea.

  • Well, don't go expecting a miracle.

  • Especially if you put a bunch of sugar in it like I do.

  • Even the most optimistic studies suggest that drinking green tea leads to losing a couple

  • extra kilos over about twelve weeks.

  • And even so, lots of caffeine can be dangerous.

  • So, when it comes to what's on the market today, that's it.

  • But what about stuff that ISN'T on the market?

  • Most scientists involved in making the fat-busting drugs of the future believe that a commercially

  • viable option is at least ten years away.

  • But we do know a bit about how they might work.

  • One weight loss treatment currently in development aims to work by targeting your body's circadian

  • rhythm.

  • We've talked about this before: Your circadian clock regulates rhythms in many of your body's

  • processes: including food intake, as well as fat and sugar metabolism.

  • And when your circadian clock says it's time to burn fuel, it activates a protein

  • in your body called REV-ERB-α.

  • This protein works by boosting the number of mitochondria in your cells.

  • Mitochondria are like your cells' power plants: they take in fuel, and turn it into

  • energy that your body can use.

  • And your body breaks down the fat molecules in your fat cells to fuel your mitochondria.

  • So, to figure out what role REV-ERBcould play in weight loss, researchers injected

  • it into some super wimpy mice.

  • Like, I don't know what else to call them.

  • These mice were just...not athletic.

  • They had poor endurance, their muscles were 60% weaker than normal mice, and their muscle

  • cells had fewer mitochondria.

  • They were like what we'd be like if we were sitting on the couch all day eating chips.

  • The researchers injected these mice with REV-ERB.

  • And all of their cells began producing lots of mitochondria.

  • Soon, the mice could run significantly further and longer than untreated mice.

  • Obese mice given REV-ERB lost weight, too, and their cholesterol even improved.

  • Essentially, REV-ERB provided a whole-body boost to their metabolism: like what happens

  • when you get lots of regular exercise.

  • It made it so that the mice's bodies just burned calories at a faster rate.

  • Even when they were doing nothing.

  • Excellent!

  • Put that in a pill.

  • Give it to me.

  • I want to take it.

  • So, there's a problem right?

  • Just tell me what the problem is.

  • Well...in low doses, REV-ERB doesn't seem to do anything.

  • And in high doses...it's toxic.

  • While it speeds up the development of mitochondria in the short term, it impairs your cell's

  • ability to produce healthy mitochondria in the long term.

  • And your cells need healthy mitochondria to...stay alive.

  • Since rampant cell death is something we want to avoid...a weight loss treatment based on

  • REV-ERB is going to need more work.

  • Other treatments in development seek to take advantage of the calorie-burning wizardry

  • of brown fat.

  • Brown fat is good fat.

  • Yes, there's good fat.

  • You actually have two different kinds of fat cells in your body: White fat cells just hang

  • on to fat for whenever your body needs it.

  • It's the kind of fat that gives you the love handles and makes you jiggle.

  • Brown fat cells are different.

  • They're not supposed to STORE fat: they're supposed to BURN it.

  • Brown fat raises your body temperature when it gets cold by breaking down fat into chemicals

  • that release heat.

  • It can do that because it's packed with mitochondria.

  • Which, are brown; that's why they're called 'brown fat cells.'

  • And the mitochondria in brown fat have a protein in them called UCP1 that tells them to act

  • like tiny fat-burning furnaces.

  • So...what if there were a way to turn white fat cells into brown fat cells?

  • Actually...there is!

  • Maybe!

  • The key is a hormone whose existence in the human body was only confirmed early in 2015:

  • It's called irisin.

  • Irisin turns out to be one of the many hormones released by your body when you exercise, along

  • with more well-known ones like testosterone and adrenaline.

  • But while testosterone stimulates muscle growth and repair, and adrenaline stimulates the

  • breakdown of fat and sugar in your bloodstream for energy, irisin stimulates the production

  • of mitochondria and UCP1 in your white fat cells.

  • Which turns them into brown fat cells.

  • So, if scientists can figure out how to stick that stuff into a pill or a syringe, they'd

  • theoretically be able to kick your brown fat cell production into overdrive.

  • Which would mean lots of fat being burned without you needing to do a thing.

  • But, since they've only just figured out that irisin in humans exists, that's a long

  • way off.

  • Another potential treatment involves developing a way to inject brown fat stem cells into

  • white fat cells, to teach the white fat cells how to produce more mitochondria on their

  • own.

  • Researchers at Harvard have developed a compound that lets the brown fat stem cells do this.

  • And I'd really love to tell you how, or even what that compound is; but since it's

  • probably worth billions of dollars, it's kind of a secret.

  • And .. we do know already know at least one downside to this possible fat-burning drug:

  • the compound also happens to be an immunosuppressant.

  • It interferes with your body's natural inflammatory responses.

  • Which is really bad.

  • Because you need your inflammatory response to let your immune cells reach invading bacteria

  • and stuff.

  • Without that response, even minor infections could potentially become really serious.

  • But other scientists elsewhere are working on lots of other things to allow you to someday

  • be both lazy and have a healthy weight at the same time.

  • Still, you shouldn't hang up your running shoes anytime soon.

  • For now...we're stuck with getting and staying in shape the old fashioned way.

  • More running; less bacon.

  • But thanks for watching this episode of SciShow, which was brought to you by our patrons on

  • Patreon.

  • If you want to help support this show, just go to patreon.com/scishow.

  • And don't forget to go to youtube.com/scishow and subscribe!

I'm going to guess that you've been on the internet before, and thus you've seen

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Weight Loss Pills: Fact Or Fiction?

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    joey joey posted on 2021/05/05
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