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  • ["Preach not to others what they should eat, but eat as becomes you and be silent." - Epiclelus]

  • In the wealthiest circles of Victorian England, bizarre fads ran rampant.

  • But perhaps none was as strange as the tapeworm diet, in which dieters swallowed an unhatched tapeworm and let it grow inside them by consuming undigested meals.

  • Obviously, this is an exceptionally dangerous and unhealthy way to manage your weight.

  • However, while modern fad diets aren't usually this extreme, they do promise similar resultsspecifically, losing weight fast.

  • So, are there any fast diets that do work?

  • And are any of them actually healthy for you?

  • To answer these questions, let's consider a thought experiment.

  • Sam and Felix are identical twins, both planning to go on a diet.

  • They share the same height, weight, fat, and muscle mass.

  • But Sam is hoping to lose weight slowly, while Felix wants to go fast.

  • Sam's plan is to gradually decrease his calorie intake and increase his regular exercise.

  • With less energy coming in and more being expended, he's creating an energy deficit inside his body.

  • To compensate, Sam's body begins breaking down his emergency glucose supply stored in the liver in the form of glycogen.

  • Then, after 4 to 6 hours, his body starts burning fat cells as a major energy source.

  • This process releases lipid droplets, which are broken down into compounds that float through the bloodstream and provide energy to organs and tissues.

  • Felix aims to create a similar energy deficit by dramatically cutting his calorie intake.

  • Unlike Sam, who's still eating smaller meals, Felix is eating almost nothing, and his body responds by going into a starvation response.

  • Felix's body breaks down his entire store of emergency glucose in just 18 hours.

  • And while Sam steadily replenishes glycogen with every healthy meal, Felix's low-calorie diet does not.

  • Desperate for energy, his body starts breaking down other materials, including his muscles.

  • Meanwhile, Sam's regular exercise is maintaining his muscle mass.

  • This means he'll use more energy both during exercise and at rest, making it easier for him to lose weight.

  • Felix, on the other hand, is losing muscle mass and burning fewer calories than ever for his body's basic functions, making weight loss even more difficult.

  • Despite all this, there's one element of Felix's fast diet that might make him think he's on the right track.

  • Every gram of glycogen is bound to several grams of water.

  • This can add up to 2 kilograms of water weight, all of which is lost when the glycogen is depleted.

  • For Felix, this might seem like he's losing weight fast.

  • But as soon as he stops starving himself, his body will replenish its glycogen store and regain that weight.

  • Clearly, Felix's plan does more harm than good, but extreme calorie reduction diets aren't the only regimens promising to shed weight fast.

  • Plans called "detoxification diets" either promote or restrict certain foods to provide specific nutrients in high quantities.

  • These can be useful for addressing some nutritional problems, but they're far too specific to be used as general cure-alls.

  • For example, for a person with low vitamin A, a juice diet might be helpful.

  • But for someone high in vitamin A, juicing could be disastrous.

  • And regardless of personal nutrition, maintaining a juice diet over multiple weeks is likely to compromise the immune system due to a lack of essential fats and proteins.

  • Therein lies the problem with all these fast-moving diets:

  • Whether you're cutting calories or food groups, extreme diets are a shock to your system.

  • There are well-established rates of healthy weight loss motivated by both diet and exercise that account for genetic and medical differences.

  • And staying on those timelines requires a dietary lifestyle that's sustainable.

  • In fact, some of the worst side effects of extreme diets are rarely discussed since so few people stick with them.

  • It also bears mentioning that many societies have unhealthy relationships with weight,

  • and people are often pressured to diet for reasons other than health or happiness.

  • So, rather than trying to lose weight fast, we should all be taking our time to figure out what the healthiest lifestyle is for ourselves.

  • With new diets emerging daily, all claiming to have the answer to healthy eating,

  • how do we distinguish what's actually good for us from what advertisers want us to believe?

  • Find out how to spot a fad diet with this video.

["Preach not to others what they should eat, but eat as becomes you and be silent." - Epiclelus]

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B1 US TED-Ed weight felix diet glycogen energy

Is it possible to lose weight fast? - Hei Man Chan

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    shuting1215 posted on 2022/12/01
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