Is it possible to lose weight fast? - Hei Man Chan
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 results;
specifically, 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 two 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.
