Hey since of what she puts in must come out, Pinkie must just take some absolutely massive, level4 biohazard, toilet desecrating mega shits every single day.
 
I wonder if she has her own private bathroom, the cakes certainly wouldn’t want to share, or pass by it in the hall.

@Master Fox  
This is also how biotics work in Mass Effect. They take in 4500 calories a day in order to fuel their abilities.

@PonyPon  
The reason I say Magic uses up energy is from an old PS1 game Wild Arms. Cecilia the mage claims, as she’s eating a bunch of burgers more then the two warriors she’s traveling with, that magic uses up body energy including body fat.
 
So that’s a bit of a headcannon there. The raw energy to supply the magic comes from somewhere inside the pony and it’s possible using an excessive amount of magic could also burn extra body energy not just causing headachs.

@ALIS
 
…
 
Did Pinkie eat the blue ribbon?

Fatness does not always account for inactivity. Have any of you ever heard of D. Boon (of the bend the Minutemen) before? He was 300+ pounds (closer to 250 by the time he died in a car wreck) and he was a guitarist who hopped around on stage a lot. Reminds me of Pinkie Pie a lot, actually.
 
Linked is a video, possibly the very last video shot of him before he died?
 
https://www.youtube.com/watch?v=206f0dLjtds

 

 
It’s not emphasized in the show because it’s not her “defining feature”, but Pinkie Pie is probably one of the most athletic ponies going. She’s arguably as strong as Applejack, and (on the ground) as fast as Rainbow Dash. So I wouldn’t consider her the “chubby one”. If anything, her humanized form ought to be like Applejack’s–very muscular.

Maybe I’m missing something, but Pinkie has the same body model as the others…
 
Until where I can see, this whole discussion shouldn’t exist.

@PonyPon  
I was just going off of Master Fox’s list.

@MLPFan2012  
How do you figure?
 
I wouldn’t think that requires much muscle work, more mental strain.

I can picture Pinkie with some amount of visible pounds on her. It is possible be chubby and active.
 
If any of the main six were to be heavy it certainly be Twilight and/or Fluttershy given as they’re the lest active(though Twilight likely burns a good of fat using her magic).

@Master Fox  
You… Well, let’s just say I disagree.
 
Least Likely
 
Applejack - She spends basically all of her time doing hard physical labor. Even beyond most farmers. She’s an athlete, beyond just an ordinary tree bucker. She puts most ponies to shame when it comes to exercise.
 
Rainbow Dash - Even though she spends a great portion of her free time training to be fast and agile, she spends most of the remainder lazing about; napping, hanging out with her friends, reading books, daydreaming… She’s no stranger to laziness. Besides that, she’s also very bad at restraining her urges. I wouldn’t put it past her to order the biggest fattiest meals whenever she went to a restaurant.
 
Fluttershy - It takes a hell of a lot of work to take care of a few pets. Fluttershy has hundreds of animals to take care of. Beyond that, it’s implied that she has named each one of them, and spends enough time with them to have formed a close bond.
 
Rarity - Even though her job is mostly sedentary, she also spends a great deal of her free time out and about meeting ponies, dealing with customers, and probably exercising. True ladies don’t have love handles, after all.
 
Pinkie Pie - Even though she spends almost all day in motion, she also eats. She eats a lot. Hundreds of pounds of fatty and sugary foods per day. Giving an extremely rough estimate, her calorie intake could be as high as five thousand per day. Only Olympic Swimmers would be able to keep that at bay.
 
Twilight Sparkle - The most sedentary of the lot. We don’t know much about her diet, so it’s possible (read: very probable) that she organizes her caloric intake to match her activity level.
 
Most Likely

My personal order from skinniest to most likely to be plump.  
1 Rainbow Dash - She’s always training and trying to be streamlined.  
2 Rarity - She would be the kind of girl to not like having a few pounds visible.  
3 Pinkie Pie - Inspite of all the fatty foods she eats she can break the 4th wall, zip across ponyville and uses up the most energy.  
4 Applejack - She eats hearty big meals but that gets burned away by all the hard work. She’s most likely heavier then normal ponies but that’s muscle.  
5 Twilight Sparkle - She could be number 6 if she wasn’t too busy with her nose stuck in the books reading all the time. She burns most of her fat using large amounts of magic.  
6 Fluttershy - She’s got the most relaxing lifestyle of them all just spending time with animals. So she’s able to get away with being a soft looking girl.

@Muffinshire
 
Well, she does tend to burn a lot of calories.

Also eats literally hundreds of pounds of sugary and fatty foods every day.

do you think Pinkie Pie has any bit of logic at all?

She’s channeling the common anime and comic book power of eating endlessly and not gaining a single pound.
 
She does exercise, too, for what that’s worth…

Dude, her fucking diet. She will die at 40.

Maybe Pinkie is just ABSOLUTELY BUFF under all that flab.

@pwingbrony  

for me she is the short who looks like a little girl (loli-type)

Just because of her voraciousness. If Twilight were to eat the way she did in Twilight Time more often, she would be more often referred to as the fat one. She is probably the least active of the six.

It’s so unfair, why in Equestria would anyone think this of Pinkie.
 
 
 
 
 

 
I see absolutely no reason and am at a total loss…

@Muffinshire  
Pinkie burns off all the calories she gains with her excessive motion

Mommy’s little piggie!