Metabolism vs Body Fat

I've got plenty of body fat and am always cold. I think insulation is useless if the furnace is off.

Fat: A big wall climber said he did this in an issue of backpacker about 10 yrs ago (think the first name was Pete?), scarfing down fat-laden calories. Visiting family and friends during the holidays (Nov and Dec), gaining extra calories has never been a problem. Haha, but I'd burn it off in the snow Jan-February.

Excess fat can be miserable over the summer though -thigh chaff, etc… I took a database class in 2012 and sitting down coding, I put on some weight that adversely affected my summer hiking. Had to take it off.

Metabolism: maybe the medical people can weigh in but every calculation for basal metabolic rate (BMR) I've seen has increased age slowing down metabolism. Kind of at the point right now where I'll take more health over more wealth (once I mail my tax payment to Uncle Sam). Problem is finding a physical job when the gray hairs come in. Especially with a lasagna and pizza addiction…. I'm just going to have to find a bike commute friendly job.

I say this as a chunky chicken that there is no good reason to pack around extra lbs. If you're going to pack an extra five pounds, it'd be better spent on down insulation than on a mountain of @$$.

My experience over the years as a guy who's been crack skinny, to morbidly obese, and who is currently putting in a lot of effort to drop weight, who had a very high metabolism in his youth but not so much anymore… I've always been warmer than most. Regardless of BMI, if I see the temperatures are going to be above 30*, there's really no point for me to bring a puffy as I won't be uncomfortable without it and am fine in just a hard shell.

IMO some extra blubber will probably help some but not enough to justify extra moon pies over appropriate gear.

So as a 23 year old who works outdoors on a chemical plant and runs 4 times a week, I shouldn't be considering eating more junk to keep warm?

Well that's no fun.

Having been 211 and 30+% fat at one point and currently running 135ish and 6ish% (I'm 5'8) I'll throw my 2 cents in. Fat is far warmer than a higher metabolism, to a point. I'd say 12-15% body fat is about optimal for men. When I was around 170 lbs, I could sit outside in the low teens with a fleece beenie and 60g synthetic jacket. Now I need a mid-layer and a Rab Infinity for similar temps, and I'm often still cold.

That has been my experience as well, Chris.

On a side note, you lost approximately 20lbs of muscle in the transition. I wonder if that is why you are colder now as well? I am not sure that we can say that higher levels of fat promote warmth in isolation. I suspect muscle does as well.

"Having been 211 and 30+% fat at one point and currently running 135ish and 6ish% (I'm 5'8) I'll throw my 2 cents in. Fat is far warmer than a higher metabolism, to a point. I'd say 12-15% body fat is about optimal for men. When I was around 170 lbs, I could sit outside in the low teens with a fleece beenie and 60g synthetic jacket. Now I need a mid-layer and a Rab Infinity for similar temps, and I'm often still cold."

Just wanted to point out that for a 35lb weight penalty equivalent to your weight loss, you could also carry 43 Montbell Mirage Parkas or 100 of their EX Light sweaters :)

OP,

By all means, eat the junkfood… on the trail as you'll need the calories for your interior furnace. Having done the weight creep thing for the past decade plus and letting it get out of hand, I can assure you that's it's easier to not go down that road than it is to try and find your way back.

A small note of victory, I stepped on a scale the other day with a full pack including 1.5 gallons of water and I was still lighter than I was at GGG this year. Baby steps.

> So I've read that having a higher metabolism will keep you warmer.
Oh yes, for sure, but you have to give it the fuel.

> I've also read that having more body fat will keep you warmer.
Not quite. Extra fat may insulate parts of your body better, but other parts will still get cold. Your head in particular radiates a lot of heat. And you still have to generate the heat.

I doubt it is possible to over-eat while walking with a pack. Many people lose weight during a walk because they have to burn some body fat to keep going. I've seen some startling figures there. But stop eating as soon as you get home. (The pizza on the way home doesn't count …)

Cheers

"So I've read that having a higher metabolism will keep you warmer. I've also read that having more body fat will keep you warmer."
To be clear, only fat "keeps" you warm. The metabolic process "makes" you warm. A proper ratio between them is ideal.

"I'm pitting them against each other in my head because when my body fat % is lower, my metabolism seems to work much faster."
I'd venture that the opposite is true. Once you increase your metabolic rate, you burn off excess fat.

It seems that strength training burns calories for longer, keeping your core temp higher for longer (more muscle mass recovery = more heat generators), while cardio training burns calories faster, for more immediate weight loss, but shorter recovery times, leading to lower resting heart rates (heart muscle training only) and cooler core temps from less muscle mass compounded by less body fat, and with more efficient (slower) circulation from a stronger heart.

I'd think it would stand to reason that less cardio and more strength training would increase core temp regulation better than cardio alone burning off ding-dongs and ho-ho's as fast as you can eat them.

Theoretically:

If the fat provided more insulation

Then your skin outside the fat would actually be colder, so you'de feel colder

Yet, your body would lose less heat so you'de be less likely to get hypothermia

"Then your skin outside the fat would actually be colder, so you'de feel colder"

I guess this would be true, if you had no circulatory system pumping internally warmed (and insulated) blood to the surface for heat regulation.

I really hope someone figures out an answer to this. I'm 5'10" 130 lbs. The most I ever weighed was 145 lbs after boot camp. I'm always cold. I've been eating an extra 1260-2100 kJ per day trying to put on weight. In the meantime, I bought some sweet icebreaker 200 weight longjohns that help a little. My GF and I battle over the thermostat, as she's a bit plump.

I've thought about eating more junk-y food when hiking but I've always enjoyed eating relatively fresh stuff. It helps that in Europe there are lots of trails leading between mountain huts, towns etc so one can restock fresh food easily and time lunch stops to be next to where you're going to buy lunch from – handy!

It would be nice if I could get hold of the sort of food stuffs I read about on blogs and on here but I'd have to do a lot of my own research into the higher calorie/gram food – most UK bloggers seem to rely on dehydrating their own meals or buying from the limited number of bagged dehydrated food companies. Not eating meat also narrows my options, particularly in France…more than in other countries, they don't seem to understand.

I'm drifting wildly off topic.

I was always hoping that trail running and therefore keeping my metabolism up was good for my hiking but I see SO many chubby/overweight middle aged men hiking that I thought I might be doing something wrong ;)

on another note – trail running and hiking use such different muscle groups…I always forget until I don't do one or the other for a week or more.

edit: Daniel – my girlfriend has the best metabolism of anyone I have ever known. She eats more than I do and never puts weight on, despite exercising much less than I do. she always complains she's cold but when we share a sleeping bag its definitely not me who is creating the warmth.

"Then your skin outside the fat would actually be colder, so you'de feel colder"

I guess this would be true, if you had no circulatory system pumping internally warmed (and insulated) blood to the surface for heat regulation."

If the fat layer kept you warmer at all, then, your skin would be colder than it otherwise would have been.

… I was always hoping that trail running and therefore keeping my metabolism up was good for my hiking but I see SO many chubby/overweight middle aged men hiking that I thought I might be doing something wrong ;)

A cook in the city I have mostly been living would "fast-walk" the wide median of a major highway year after year – first saw him in early 1990's and would catch glimpses of him for about 20 years. The guy constantly had a belly, so I'm thinking the diet has something to do with it.

It could be that simple calories in>calories burned from the physical sciences. Also ran into an article from Dr. Mark Hyman (M.D.) who writes from his viewpoint, calories are not equal … http://www.huffingtonpost.com/dr-mark-hyman/calories_b_5126008.html?utm_hp_ref=healthy-living

Short-version: his example is a person can easily drink 750 calories in a soft drink (we have large sizes here in the US) but there's no way to eat 750 calories (or 21 cups) of broccoli in a meal.

Medical doctors have increasingly getting involved in this, so before the flame war starts there's probably other points of view, including athletic trainers.

I was always hoping that trail running and therefore keeping my metabolism up was good for my hiking but I see SO many chubby/overweight middle aged men hiking that I thought I might be doing something wrong ;)

There's a difference between being fit and looking fit. One is 100% exercise, the other (more or less) 100% diet. You can be one, both, or none.

I don't know if there is much to "figure out" about this, but I will add my two cents since I have changed a lot in the past 8 years (and I can talk about fitness forever even to the uninterested).

Coming out of high school I was skinny (although at the time I thought very muscular haha). 6'2 185 lbs with a little fat and a little muscle. When it was cold out, I was cold.

In college I got into bodybuilding. At my heaviest I was 230 at around 16-17% bodyfat (e.g. abs are just barely visible). I stayed pretty warm all the time, really warm when I was moving and warm enough when I was stopped.

In spring I would start getting down to ~10% bodyfat (abdominals are well defined when relaxed) and would stay plenty warm when moving but get cold fast when I stopped.

Now that I'm out of college I have pretty much settled into the body I want to stay in. Around 210 lbs and ~14% bodyfat. At this point I still stay plenty warm when I hike (I'll wear a long sleeve shirt and maybe another short sleeve underneath down to around 20F when moving) and stay warm long enough to get bundled up/ filter water/ set up camp. But this is just the easiest state to maintain for me and it looks good enough.

Long story short: Muscle will keep you warmer while moving, but isn't worth the weight and requires more calories. Fat will keep you warmer while still, but isn't worth the weight.

If UL hiking is your #1 priority, you should be as lean as possible with just enough leg muscle to get by. (Don't tell this to the UL blog writers though).

However if you had to be overweight (For years I was considered "obese" by BMI standards) you can see my vote is for de mooooooooseles.

I find myself having several personal summers all day long these days. I find it far more warming than my increased Texas weight.

Just saying.

My wife would admire this post ^

I definitely used to run hotter as far as sitting still goes, when I was younger and my metabolism was going great guns. Probably typical. But since you have no choice in the matter the question is really moot. You don't get to choose to have a higher metabolic rate – well, perhaps you can influence it slightly by being more fit, but that won't be much. And carrying extra fat around in an effort to stay warm is surely a bad idea both from a health standpoint and backpacking efficiency-wise. A warmer jacket will do the job better for less poundage.

What's interesting to me is that I heat up when I get going to about the same degree as I ever did. So while basal metabolism seems to slow down as you age, the rate at which muscular activity generates heat seems to stay the same – or at least it seems that way.
Thus, as I get older I have to wear more when lounging, but still get down to the same outfit for hiking.
The other thing is that I can tell if I am not getting enough calories when it's cold. The body needs fuel to burn.

"What's interesting to me is that I heat up when I get going to about the same degree as I ever did. So while basal metabolism seems to slow down as you age, the rate at which muscular activity generates heat seems to stay the same – or at least it seems that way.
Thus, as I get older I have to wear more when lounging, but still get down to the same outfit for hiking."

This has been my experience as well.

Differences in your metabolism should have a negligible effect on how much heat you put out while moving. That will almost entirely be a function of how much weight you are moving over what kind of terrain (e.g. work being done).

Now when you have stopped moving is where metabolism comes into play. This is why many people like to eat something sugary before bed, because the spike of insulin and the new fuel for your metabolism will help your body quickly generate a bit of extra heat at rest.

nm

Have any of you guys heard of Wim Hof? He holds the record for the longest ice bath and attempted Everest in shorts (failed due to foot injury). I'm not sure how it works, but I think he just has a stupidly high metabolism. I hear he has to eat a ridiculous amount of food too.