UKC

Nutrition stuff is always discussed on here, and people talk about slow metabolism.
I have started taking note of how much I eat, and am wondering at what speed metabolism is really considered slow. So yesterday, for example, I spent 6 hours ski touring, and ate 1500 calories. According to online calculators, my BMR should be around 1300. 200 extra calories for 6 hours ski touring? I spent the whole week winter mountaineering or mountain biking also, and have consumed pretty similar calorie counts. I have loads of energy, and am not loosing weight, so not under eating.
Is my metabolism too slow? Is it worth bothering a doc about?

In reply to girlymonkey:

If you don't feel unwell, please don't bother a doc! We're all different, and a GP won't be able to answer your question with any degree of certainty.

Hope you are well! You sound it, plenty of exercise and not feeling unwell!

N

In reply to girlymonkey:

I am the opposite. Skied(? spelling?) from lift open to lift close all week, averaged 4000kcal/day, lost a kilo!
I am sure that between us we help to stabilise the average.

In reply to girlymonkey:

It's incredibly restrained of you to eat only 1500 calories! After 6 hours ski touring I'd... well a lot anyway.
If you have energy and can bear not to eat more then good for you!

In reply to girlymonkey:

I reckon my daily basal requirement is around 1700-1800 calories, which given the size of me is surprising. But back in the days when food was not readily available it was probably an evolutionary advantage.

So as others have said - do you feel sick? If not, no problem.

Neil

In reply to girlymonkey:

Not ever feeling ill, but constantly cold. I presume this is due to my body not burning calories. I have tried eating more on winter hill days to see if it does warm me up, but it doesn't, I just put on weight! So while not ill, higher hypothermia risk! (I'm not just meaning a bit chilly, I get properly cold)

In reply to girlymonkey:


It's all that time you spent in Russia in houses heated to 30 degrees!

In reply to girlymonkey:

That's cos you are in Stirling!!

Are you small? The smaller you are, the bigger your surface area to volume ratio, and the more heat you lose.

Why don't you just wear more clothes?

In reply to girlymonkey:

Look up information on those who had thyroid problems: they can go from an overactive state where they can eat almost anything without putting on weight to having to diet very carefully when their thyroid activity is controlled/removed.

In reply to tlm:

"The smaller you are, the bigger your surface area to volume ratio, and the more heat you lose"

Isn't the other way round?

In reply to Richard Carter:

No. If you got a big person, and cut them in half, into two smaller people, you would reveal 2 new lots of surface area, one on either side.

It is why shrews have to eat so much.

In reply to tlm:

But they aren't cut in half :-P

My wife and I weigh the same, but she's quite a bit shorter than me. So she's a closer approximation to a sphere which is the optimum surface/volume shape...

In reply to girlymonkey:

Tell me about it - I watch what I eat, only have a bit of wine at weekends and do 15 hours a week hard cycling, 2x 5h rides and 2 x 2/3 h rides. Have I lost weight this week - Have I feck!

Meet my mate, no aerobic activity whatsoever, full English every day, a real ale fan and curry fan - skinny as a rake. bastard.

E

In reply to Enty:

He must be doing something or not eating that much, otherwise where does the energy go?

In reply to Richard Carter:

If you weigh the same, then you are the same volume. So if she is also shorter than you, then yes, she will have a smaller surface area to volume ratio.

I was talking about size with regards to people who are proportionally smaller, rather than just meaning height, so thinner as well as shorter.

Babies have a larger surface area to volume ratio than adults, which is part of why it is harder for them to regular their temperature.

In reply to Richard Carter:


I do wonder if there is an 'efficiency' aspect to this. Maybe those who eat loads and don't put on weight (I include myself in this group) absorb less of the energy from their food, and basically pass it straight out.

For practical purposes we measure energy intake based on the energy value of food we eat, but that necessarily makes the assumption that this is equal to the energy extracted from the food, or at least the loss is constant across a population. I have no idea how valid this assumption is.

In reply to Submit to Gravity:

I used to get told off for opening the windows! They were ridiculas out there, particularly in Siberia. Even I don't get cold enough to heat a house that much!!

In reply to tlm:

Yes, I am small, so the surface area thing does come into play. I do wear loads of clothes, that's how I cope, and I don't stop. I guess I was kind of hopeful there might be something that could be 'fixed' that might mean my body would do the job of keeping me warm! Not all small people get so cold, so not just a surface area problem.
I wear a down and a primaloft layer together on the hill most days in winter!

In reply to Richard Carter:

Nope, in the same way that I can be uber active and hardly need any food, there are people who eat non stop and are rakes with no effort.

In reply to girlymonkey:

Typing as a girl with Hypothyroidism, who broke her body and metabolism by "surviving" on
1500 cals a say - I hope you of don't mind me saying that 6 hours ski touring on 1500 calls is way too low, weight loss goals or no weight loss.

If anything it's also hypothermia in the making.

Now, I don't know what height, weight you are or your diet and exercise habits, But most girls, who consider themselves on a diet, do not need to lose as much as they think they do.

Despite what sports scientists might say, BMR (much like our BMI) depends on way much more than just calories in, calories out.

1500cal a day is what dieticians would recommend to an average height woman who is 'overweight and obese'. Which is usually roughly 5kg-1 stone ish excess.

Therefore leaving a 500 cal deficit, with eating right and healthy level of exercise should result in a 1lb weight loss per week. But this is for your average lady, going to work, with kids etc, who does ski tour for 6 hours, if she's lucky, she fits in a 20 exercise video or go on the cross fit machine at the gym.

I suspect, if you are not losing weight on 1500 cals a day, you do not need to lose that much weight in the first place. Or if you do, that amount of calorie deficit is way too high, given your activity level.

Ski touring is just about one of the most aerobic activities you can do, combine that with regularly exposing yourself to cold temperatures, it's asking for trouble if you don't mind me saying so.

If I am ever trying to diet, I would not do it on a day in the mountains.
Whenever I climb/mountaineer, weight loss goes out the window and priority is taking on board high fat, high protein energy foods to help me stay warm and get me up those hills!

If you've got concerns, go see the Dr, I wish I did before I broke my thyroid. Or take a step back and assess your diet and exercise levels. Sometimes we can over do it

In reply to Turnertower:

My point is that I'm not on a diet, that is just all that my body uses. I keep track of my weight as I don't want to gain any. Im not trying to loose weight, just stay stable.
I am very small, so the BMR calculator put me at 1300.
I am fairly fit at the moment, so I don't find ski touring crazily tiring, I get much more tired post holing through deep snow.
This was why I asked the question, it does seem very low but is genuinely all my body uses!

In reply to girlymonkey:

A very efficient metabolism... you could as others have said be hypothyroid, but equally if you feel OK...

Neil

In reply to Neil Williams:

Constantly cold is a hypothyroid symptom...

In reply to ebygomm:
Indeed. But that also depends on what extent, and there are other causes e.g. poor circulation.