Exercise & Recommended Calorie Range Interactions
 

This is something I've been wondering, as my continuing weight loss allows me to be more and more active.

Let's say that my normal calorie expenditure is somewhere in the 2600-2800 range or so. This leads me to put a floor on my calorie consumption at 1600-1800; any less than that and it starts to actually slow down my losses and is just a generally bad idea for overall well being (already experienced firsthand).

So what happens if I have an active day and instead burn 3500 calories?

Clearly I could eat more if I wanted to - but I don't really want to. Should I do so anyway to avoid making my body think there's a critical shortage, or is it somehow different because this was an exertion well beyond baseline metabolism?

My answer is based on my own experience... and what I've read other people have experienced:

You can't predict it.

What happens under one set of circumstances won't the next time. A particularly active period (without an increase in calories) may result in a temporary weight loss... or it might NOT... for me. I see this when we go snowmobiling in very cold weather. I KNOW I'm using more calories between being active all day (we ride hard) and my body struggling to stay warm. On those days it's likely I'm not eating more than usual since trail side options are very limited and some of the people we ride with don't "do lunch". They over eat at b'fast and dinner instead... which I don't do.

You'll likely see the same things... which is to say, you'll get very different results from what seems to be the same circumstances.

I'm a BIG believer in eating to your hunger. If a very active day increases your hunger, then eat more (of the right stuff). If your body is satisfied with less... that's ok, too. I think that if we give ourselves "permission" to feel and follow our instincts that we won't overeat and we will do what's best for our bodies in each situation. We're physical beings designed to function properly... it's what we do in our heads that messes that up. LOL

I'm also, for the record and because we're talking calories here, NOT a believer in "starvation mode". At least not for the average overweight dieter. We have a survival response to true starvation that will prolong life... but let's face it, WE are not in any danger of starving to death. All you have to do is look at an anorexic teenage girl to understand that you CAN starve your body thin. There is no "starvation mode" that keeps these people from losing weight when calories are restricted. It irks me when someone doesn't lose weight for a week or so and they're told EAT MORE because you're in STARVATION MODE!!!! Fat is there for us to use when food is not available... why oh why would an organism be programmed to NOT use that source of energy that could save its life?

I don't know for sure... but it just doesn't pass my sanity check to say that restricting calories prohibits weight loss in someone who is overweight. Heck it works for anorexics, doesn't it???

Didn't mean to turn your post into a personal rant... sorry about that JD! LOL You asked a good question:

"Should I do so anyway to avoid making my body think there's a critical shortage, or is it somehow different because this was an exertion well beyond baseline metabolism?"

IMHO... no, you shouldn't eat more unless you feel you NEED more. And you might. If not the day you're overly active, then the next day. There, I brought the topic back around. http://www.lowcarbsite.com/images/smilies/icon_wink.gif

Tril

Tril,

Don't worry about co-opting my post, I like the dialog.

To be clear(er), I'm not saying that I believe too few calories will completely stop weight loss. Clearly that's simply illogical and refuted by all our experiences.

However, based on my own experience, I do believe that there is an "optimal" amount of calories (different for every individual set of circumstances) for weight loss under which (after a prolonged amount of time anyway), you'll actually lose LESS.

I believe this is because the body's metabolism is adapting to the new situation, thinking that you're going to be in it for a while. This was probably a very useful survival trait at one point, but I don't think anyone posting on this forum is actually in danger of starving to death (this isn't a jab at anyone's weight, I'm just saying having electricity + a computer + an internet connection means we're all really well off based on global standards).

I'd love to follow your "eat till you're not hungry anymore" idea, but the problem is I simply never get very hungry on Atkins. At times when I wasn't paying close attention I've caught myself falling under 1200 a day (for a period of weeks), and still not "hungry" - but I was tired, irritable, etc, AND my weight loss slowed down. When I started forcing myself to eat at least 1600 a day, it picked up again.

Perhaps coincidentally, perhaps not - this 'magic number' for me, turns out to be about 1000 calories a day under what my estimated daily expenditure is, and 1000 calories * 7 days a week works out to about 2 pounds a week - which seems to be a widely held guideline for the maximum sustainable healthy losing rate.

While these are only a few anecdotes, it's consistent enough that I do believe the two are linked - although I may very well be wrong.

However, in taking the time to compose this reply to you, I think I've answered my original question - my metabolism only took a turn for the worse during periods of PROLONGED low calorie intake (maybe that's why intermittent fasting works?). As I don't exercise significantly every single day, I'm probably fine ignoring it and not upping my intake to compensate.

I'd be thrilled if batlou wants to chime in with his experiences though.

"However, in taking the time to compose this reply to you, I think I've answered my original question - my metabolism only took a turn for the worse during periods of PROLONGED low calorie intake (maybe that's why intermittent fasting works?). As I don't exercise significantly every single day, I'm probably fine ignoring it and not upping my intake to compensate. "

See... I agree with this. I think it's the PROLONGED caloric restriction that leads to what might be called "starvation mode". I don't think it happens in a day or two, or even a week or two. I think it happens when the fat stores are depleted and body is forced to do something or die. So it compensates in any way possible to prolong life... until a food source is found. Lack of food/calories will naturally lead a person to slow down due to a lack of energy. This alone will prolong life. Feeling lethargic... cranky... tired... means you won't feel like doing any unnecessary physical activity. That conserves precious energy stores.

If you watch the show Survivor, you'll see this toward the end of the 39 days they are lethargic, cranky, irritable and can't perform well physically. They also LOSE WEIGHT by the bucket loads. Again... I can't see that the "starvation mode" has kicked in and prevented these people from losing weight in those 40 days.

I'm not condoning starving yourself to lose weight... not at ALL. I'm just saying I don't buy the "starvation mode" theory as it pertains to a person eating less (not actually starving!).