T Nation

Fast/Slow Metabolisms: Truth or Myth?


Is it really true that some people have faster or slower metabolisms that make it difficult to add or lose weight? Or are people who claim that they can't lose/add weight not really eating or exercising like they say they are?

If two guys are the same height, eat identical diets are perform the same type & amounts of physical activity, will they always be the same weight and body fat percentage?

How much of a actor is "metabolism speed," all other factors (diet & exercise) being equal?


I'm no scientist, but I have friends that live on wendy's, donuts, pizza, and pop tarts, and they are skinny as hell. They literally eat 2000 Kcals worth of chips and junk as a snack.
I eat clean all of the time and do twice the amount of physical activity as these people, and it is much harder for me to stya lean...

(they'll pay for it someday though)


Well, I used to eat like that. Now I try to eat clean as much as possible (hard sometimes) and drink only water (this has luckily become a habit). And let me tell you, there is a difference. Before, I was skinny. Now I'm LEAN. There's a huge difference between skinny, low bodyfat and no muscle, and lean, low bodyfat and muscle.

IMO, anyone can achieve the first. But the second makes a great physique that will make you look good nekid, and not only like you are lean when wearing a shirt.


Everyone does not have the same metabolism. Some people have faster metabolisms and need more food in order to gain weight.


Some people are also genetically gifted when it comes to gaining muscle and having no body fat. I have a friend who doesn't eat breakfast and for lunch has gummy bears and potato chips. He is around 5'8, 190lbs with about 5% body fat. My friend and I who actually eat correctly wonder what we did to deserve our mundane genes.


I have friends who eat candy,coke,and drink all the time,they weigh 170 are ripped and look bigger then my 208lb ass.I hate them so.

Yes people have different metabolisms.I can be a skinny kid at 150 with low bf at 3200kc,to have any size i have to eat at least 4300kc.


Yeah I'm like 200ish and I need to eat about 6000 cals a day to gain weight. It makes it easy to get lean though.

My friend on the other hand is about 220 and his maitenence seeems to be in the 3500 range or so.


I work with a guy who can eat the entire buffet line and not gain weight. This dude eats like a pig to maintain, actually. I ate at the food court one day with all the guys, and what I saw from him was remarkable. He ate like 4 times what I ate ( I have an appetite that takes a couple of fast food meals to fill, so dinner at my place is decent).

It seems like he has a tapeworm. A 10 lb gain in bodyweight was cause for joy for this guy over a 9 month span. Of course pizza was the prize. He weighed in at about 116 lbs at 5'9". Yeah, you read that correctly.

It seems impossible for me to shed all my belly fat, even on a 4 month super strict non-carb diet consisting of no more than 1500 2000 calories per day from chicken, tuna, and hard boiled eggs, and plenty of cardio while using HOT-ROX and carrying a heavy back pack all day long while I walk all over the place.

This indicates wide variations in metabolic rates, dude. It sucks.


I know for sure people have different metabolisms...

Before I got into working out, I ate very sloppily...and I was always eating...cinnamon toast crunch for breakfast, wendys for lunch, chips or a candy bar for a snack, healthy dinner, then chips or something before bed...

and I have a friend who eats fairly healthy (good breakfast, subway for lunch, healthy dinner, etc)...

I've alway been rather 'healthy' looking...not muscular, not fat, not skinny and my one friend is huge...I bet he could gain muscle if he just started lifting a few times a week.

And me, when I was in highschool, I actually had a girl break up with me because she saw me without a shirt on and thought I was 'chubby' -- well I joined a gym and a month later I was completely ripped, six-pack and everything...went on to date her best friend, but that's another story.


Anyway, no doubt, it's really easy for some people to pack on some mass, and for others it's simple to shed the fat away...I guess I consider myself lucky...I'd rather not have to worry about putting on some extra fat while building mass because I know it will be easily shed.


Hey, I'm no expert, but it seems like four months of no carbs and restricted calories would slow your metabolism to a crawl (think molasses in january). I'm sure your body was trying to hold on to any fat it could, since it was being starved... If you are still having problems, look into Carb Cycling:



We're all unique in our individual ways (bioindividuality). Meaning, our metabolisms will be unique to us.

That being said, people just need to focus on what they have control over.

What they put in their mouth and what they do activity wise.


Of course, more muscle = faster metabolism.

But I think some people have gotten really good at burning carbs, by eating little else. Sugar junkies and the like. They my even act wired, like their body is trying to burn off excess energy.


I would think that having that response would lead to becoming a sugar junkie, rather than the other way around.