Backpacking on calorie deficit and ideal energy distribution…

[Kevin Burton]

I've been experimenting on doing a calorie deficit while backpacking.

So far the results are mixed.

I seem to start off strong in the morning and then tend to fade in the afternoon.

It seems that I tend to eat most of my food at the beginning of the day, and then have a 4-7 hour period where I don't eat.

That later period is where I get tired.

There are a couple options here:

1. I just get tired normally (it's a lot of energy expenditure) and there isn't much I can do about it.

2. I am tired because I've depleted muscle glycogen and have low blood sugar.

it also might be a combination of the two (factoring in single cause fallacy).

So what I was thinking of doing was bumping up my calories and consuming something like 200 calories per hour starting from a couple hours after breakfast and a couple hours before dinner.

Say have 800 calories for breakfast. Then another 800 for dinner. and then 7x 200 calorie snacks in between. One issue is that for longer trips this will be a LOT of room in my bag. 7 granola bars is kind of a lot of food.

My theory is that going TOO lean on food could be a false economy. If I cut food TOO low I'm going to be lethargic and slow which counterproductive with the weight savings I have for less food.

[M B]

I do 17-25 miles per day in the mountains usually.
I run very large caloric deficits.

There is no way to carry enough food if you do decent miles. Unless you only eat peanut butter and olive oil.

Thats why thru-hikers need town stops, to re-load on calories.

When I have "bonked" to where I cant take another step, a short rest, water and electrolytes, and a snack does wonders. Good to go for rest of afternoon.

I try to eat about every 2.5 hrs. I have a schedule. Breakfast, snack, lunch, snack, dinner, snack. I usually only stop for snack breaks, and to collect water, so Im walking at least 10 hrs per day. Some days, a few hrs longer. One of these days Im going to do 24hrs just for the heck of it to see how far I get.

[Anonymous]

"My theory is that going TOO lean on food could be a false economy. If I cut food TOO low I'm going to be lethargic and slow which counterproductive with the weight savings I have for less food."

How many days are your trips and what is your daily mileage?

[Kevin Burton]

> How many days are your trips and what is your daily mileage?

Most of my trips are 2-3 days … long weekends basically. With a few 7-9 day trips.

I think I'm going to experiment with taking a 15 minute break every 1.5 hours to lay down, drink water, and eat food.

Often what will happen is I'll be EXHAUSTED and get to camp at like 6pm-7pm…then setup camp for 45 minutes. At this point I feel totally rejuvenated and can do even more miles.

So I think I just need more breaks and regularly spaced calories.

[M B]

One of the things a lot of hikers do , is stop and eat dinner at 4-5pm in the summer, and rest for an hour or more.

Afterwards , you are rejuvenated and can knock out a couple more hours.

You should get tired if you are working hard. You are correct, resting will be beneficial.

[Jake D]

I usually have PB pretzels or trail mix in my waist belt pocket and when i leave camp after breakfast i'll throw a snack of some sort in my pants pocket to have available.

on LT we'd eat breakfast in the AM ~5:30. snack around 10, lunch at 1, maybe a small snack after that, get to camp around 5pm for dinner and a desert. we did 18-20mi/day for 16-17 trail days. Zero's and Nero's in town were good for catching up.

spacing the food out keeps you fueled up and a bit motivated for the next snack haha. This becomes really apparent after a week when you'd eat your whole food bag if you were let loose on it.

[Kevin Burton]

I just put together this spreadsheet for 22 mile days:

https://docs.google.com/spreadsheet/ccc?key=0AkBAy3nnEh65dGtEY2dTdWVZRFhIZlFoWGo0VGtTaVE#gid=1

[Greg Mihalik]

"It seems that I tend to eat most of my food at the beginning of the day, and then have a 4-7 hour period where I don't eat."

"So I think I just need more breaks and regularly spaced calories."

Apology in advance: No "talking down" is intended. This is the only way I know how to tell it.

Regulary spaced calories is the answer.

You start the day with carbo calories "in the account" from the preceding dinner and breakfast. As you hike you burn down the carbo account. By making regular carbo deposits you "stay ahead of the zero balance" curve in two ways: 1) you are adding calories along the way, 2) you are providing your body with the carbohydrates necessary to "burn the fat".

The image is the flame of the carbo candle melting a vat of fat.

You are burning 400 to 600 calories an hour . By not eating for 4 hours you've depleted your carbo account and are shutting down the "fat by carbos" metabolism, and are reduced to a crawl. At the end of the day your muscles, and your brain (20% of your metabolic load), are starved, literally.

Your body can only take in about 300 +/- 50 calories and hour, so it's really hard to get ahead of the curve once you get behind on intake. (Unless you take a long break).

Get on a "feeding schedule" (and drinking), and stick to it to stay ahead of the curve.

I get by with a 240 calories every two hours in the first few days of a trip and then go to 1.5 hour intervals, with a 340 calorie hit around 3 or 4 pm, followed by more 240's to carry me through to 7 pm. It's something you will have to learn by trial and error. But err on the "over eating side" to begin with.

Edit1: I am not advocating "calorie deficit" hiking. That was beat to death in another thread. Go there to beat that drum. BUT, if your style encompasses using body fat as a energy source, this is one way to look at it. (end of pre-emptive stike.)

Edit2: 2 mph pace, few stops, 200# (including pack), 10 to 12 hour days, 10 days at a time.

[Hiking Malto]

He nailed it perfectly. FWIW, I eat 300 calories of mostly carbs per hour, 3 mph pace, few breaks, 190 lbs.

[Hiking Malto]

One thing to add to Greg's excellent summary. At the days end you need to eat a healthy dose of carbs to make a deposit into the glycogen account. This should be done as close to the finish point as possible in order to take advantage of your body being in high burn. Failure to do this will start you in a deficit the following day.

[Greg Mihalik]

"At the days end you need to eat a healthy dose of carbs to make a deposit into the glycogen account."

+1 Thanks Malto.

Also, I often add a 250 carbo snack around 2 am while listening to the trees ;-)

[Greg Mihalik]

Kevin,
Re-reading your post, I'd say you've got it figured out.

Now just tune it.

BTW, not all "granola bars are created equal". Read those labels.

PowerBar's Harvest line is about 240 calories a bar, and include 10 grams of protein.

ProBars, though expensive are pretty good as well, and 340 calories/bar.

And if you start doing long fast trips, you may come to appreciated the joys and economy of "malto".

[Kevin Burton]

> PowerBar's Harvest line is about 240 calories a bar, and include 10 grams of protein.

This is another issue I was going to bring up… I need to look into this. A protein boosted bar would rock. Right now with my current food I would get about 80g a day.. I'd prefer more like 120-150 (or a bit more).

I've not been happy with PowerBars though… they tend to be gross. But I'm open minded.

[Greg Mihalik]

Look at the Harvest line – green labeling on the package.
It's all personal, but I can't stand any of the others….

[Kevin Burton]

The other problem with these are that the list of ingredients are just insane. Some of these things are a bit iffy .

I just found out that I'm VERY sensitive to sugar alcohols and xanthan gum which are basically in most of these modern "food like substances".

I'm just going to try to simply my diet by keeping the ingredient list short and making my own bars. At least this way it's easier to tack down what's making me sick.

[Kevin Burton]

> You are burning 400 to 600 calories an hour . By not eating for 4 hours you've depleted your carbo account and are shutting down the "fat by carbos" metabolism, and are reduced to a crawl. At the end of the day your muscles, and your brain (20% of your metabolic load), are starved, literally.

What is the "fat by carbos" metabolism that you mention?

My understanding was that these things were mutually exclusive. If you consume carbs you're going to dump this glucose into your blood stream and if the value is low enough your body will use it for fuel. Otherwise it's going to bump up your insulin which is going to convert it to fat. The other path is to convert it to glycogen.

Fat can be metabolized as fuel but it's a rather slow process.

Regular feeding of carbs will end up keeping your blood sugar high which will help with running out of energy.

But I'm now aware of this issue with carbs being needed for fat metabolism.

[Hiking Malto]

"Regular feeding of carbs will end up keeping your blood sugar high which will help with running out of energy."

This may be true while sitting on a couch but it won't be true while continuously hiking. Why? Because you are burning calories far faster than in taking them. The simple formula I plan for is this.

calories burned – 200 calories per mile.
Hiking speed – 3 mph
Total calorie burn per hour – 600
Carb intake per hour – 300
Deficit -300

Because I always run at a deficit AND I meter calories in at least hourly AND I don't stop for breaks, there is no opportunity to ever get your blood sugar high. Couple other points.

1) I have read that you should not eat a high sugar breakfast until you start moving to avoid the blood sugar spike. Makes sense.
2) I haven't played around with this much but longer breaks combined with a high sugar snack could be counter productive.
3) I believe you have to train your body to burn fat. Said another way, putting your body in situations where it has to use fat for fuel will teach it to effectively do that. In my example above, ideally you could burn 300 calories per hour in fat and avoid any significant drop in glycogen levels. Luckily you can get by with a less than that. Lets say your body can only burn 250 calories per hour in fat…. You would have a deficit of 50 calories per hour or 600 calories over a twelve hour day. This can be solved by end of the day carb consumption as well as allowing your body to catch up with fat burning overnight. But you can see that dropping carb consumption during the day will cause that deficit to increase beyond what your body can handle. You may or may not hit the wall the first day but the cumulative effects will grow.
4) altitude. If I understand this process correctly. Fat needs oxygen to burn. If that assumption is correct then higher altitudes will limit oxygen and thus the ability for fat to be used as effector for fuel. Back before I really started to focus on fueling this was a very common occurrence on many of my trips at higher elevations in the Sierra. I can remember continuously bumping up to the Wall while I was on the SHR a few years ago. Someday I will have to do that trip again to see the difference in fueling.

[David Goodyear]

At some point it becomes a chore to take in enough calories to offset the calorie deficit, sometimes to the point of " I cant eat another thing".

On a high energy winter sled trip last year, I could not physically eat enough. I needed 4500 – 5000 calories per day to replace the calories expended and fuel the night time furnace to keep me warm at -36 F. I ate like a madman and still lost 5 lbs over the course of 9 days. I tried not to but, I didn't have a choice, I hiked in a calorie deficit.

This is when examining what you are eating goes out the window (to a point) . you just need calories…dense calories in the smallest package possible – the more tasty the easier to consume.

We ate a good breakfast – mixture of carbs, fat and protein, every 45 minutes a snack, a sit down lunch, big dinners and late night snack.

We get caught up in the food labels, but remember, you still have to eat it. I found that the calorie dense probars tasted a little better with a chunk of dove chocolate in my mouth. My snack mix tasted better with fat filled fritos mixed in. I'm sure that my body burned them up before too much cholesterol attached to my arteries.

I think that the body is an amazing machine that can adapt to what you throw at it and make this the new normal. Physical fitness preparation and practicing your new eating regimes may go far to prepare you for these extreme hikes.

Great discussion. Good information.

Enjoy,

Dave

[Kevin Burton]

> Because I always run at a deficit AND I meter calories in at least hourly AND I don't stop for breaks, there is no opportunity to ever get your blood sugar high. Couple other points.

Oh agreed. but I think that's fine.

You're no where near V02max when backpacking. You're approaching it if you're running up the hill of course but not many of us do that.

I assume you're needing some % of glycogen and that you will eventually burn it up but it probably takes 1/4 to 1/2 of the day for that to happen.

Your body can help fill in the gap from fat.

You can burn 31 calories per lb of fat per day:

http://caloriecount.about.com/forums/weight-loss/able-burn-calories-fat

In my case that means I can get about 800 calories from fat. (I'm somewhat lean). The bigger guys among us can get more calories from fat.

Though realistically if I'm going to be doing 11 hour days that's 4400 calories of carbs I'm going to need and then another portion to cover my metabolic rate.

> I have read that you should not eat a high sugar breakfast

probably right regarding sugar. Complex carbs should be ok depending on the glycemic load. Even rice isn't very good as it has a high GL… wheat / oats are much better and take longer to digest.

I'm not really doing "sugar" though. Most of my carbs are complex.

Another idea could be to make a custom energy drink. Dump into your water so you're getting calories while you hike.

> ideally you could burn 300 calories per hour in fat and avoid any significant drop in glycogen levels. Luckily you can get by with a less than that. Lets say your body can only burn 250 calories per hour in fat.

I believe the evidence for this isn't very solid (see the above link) unless you're bigger. Fat metabolism is based on the volume of fat you have. It's more of a parallel system. So the more fat cells you have the more calories you can burn. But if you have fewer fat cells your body resorts to catabolism (burning protein/muscle)

[Kevin Burton]

> At some point it becomes a chore to take in enough calories to offset the calorie deficit, sometimes to the point of " I cant eat another thing".

That and (sorry if it gets gross here) the amount of defecation can become onerous and uncomfortable.

I was thinking last night that more of a gatorade or custom energy drink might work. Maybe have breakfast and dinner to help with sanity and a few smaller snacks but also get something like 40% of your energy from straight glucose/sucrose.

> We get caught up in the food labels, but remember, you still have to eat it. I found that the calorie dense probars tasted a little better with a chunk of dove chocolate in my mouth.

I get more caught up here because a lot of the frankenfoods make me sick. It might be because I'm getting older… I can't just buy some of these protein bars and eat them without feeling horrible.

> I think that the body is an amazing machine that can adapt to what you throw at it and make this the new normal.

For some of us that's true. I've found that I have to pay attention.

Caffeine timing for example is really important to me. I have to have a batch of caffeine in the morning and then not have it at ALL after 11AM. I have ADD so the early boost helps but then I need to phase off so I can sleep.

Then there are lactose issues… which also kill me. And other ingredients that just flat out make me mildly sick..

[David Goodyear]

Sorry that your body has issues with foods. That must make it really difficult to plan what to eat on the trail. I guess my post was just to say- try to make it palatable.

You might check out some of the Ultra endurance athletes diets or nutrition/hydration plans. I have friends that run 50-100 mile ultras and multi-day races. Besides being completely nuts (said with sarcasm and admiration) they rely on mostly liquid based products for replacement and fuel. I won’t pretend to understand this, but it may be a place for you to go to get a different perspective.

Good luck in your quest,

Dave

[Greg Mihalik]

Kevin,
When it comes to fat burning, search for "endurance" sites, versus "weight loss" sights. The demographics and goals are very different.

From –
Alan Couzens, MS (Sports Science), CSCS, PES
http://www.endurancecorner.com/Fat_Burning_Essentials2

Here are 2 "cherry picked" quotes –
1)
"Very good ultra-endurance athletes typically metabolize less than 40% of their energy from Carbohydrate. Accordingly, approximately 40% of their nutritional intake comes from Carbohydrate.

"Additionally, studies have shown that those athletes who burn more fat at rest also burn more fat at all aerobic exercise intensities. In this case, a resting 60/40 split typically results in fat burning of 30-40% at Half Ironman-Ironman intensities. More commonly fat burning is less than 20% for average Ironman athletes." [edit: at 20%, if your burn rate is 500 per hour, that's 100 per hour of fat, maybe 1000 for the day]

2)
"In the course of our lab testing we have seen a wide range of fat burning abilities at ‘normal’ easy-steady training intensities, anything from 2kcal/min to 10kcal/min." [edit: 120 to 600 kcal per hour]

So there is a wide range for "fat utilization", and a lot of caveats along the way.

But I have reservations about the "31 cal/lb" max burn rate.

[Hiking Malto]

Thanks Greg for again saving my fingers from typing what you wrote above. To that I will add……

The 31 calorie per lb. can't now be correct universally and more particularly for me. If that were true then I would have hit the wall on trips such as a four day 150 mile high elevation gain trip. On that trip I ate a total of 16,500 or roughly 4100/day. With full packed out weight I would be a 205 average and the total calories burned would have been roughly 30,000. The difference between the total would have 13,500 calories.

When I came back from my PCT hike I weighed in at 174 lb and had very little fat at all, lets use 10 lbs. I had also lost normal muscle mass so lets say that I rough 5 lbs giving me a fat free weigh of roughly 170 lbs. weighing in at 190 I would have 20 lbs of fat. Using the estimate of 31 calories per lb, my fat would be able to generate only 620 calories per day or a total of 2480. What happened to the other 10,100 calories?

You may say "muscle mass was burned" and that could be partially right but I saw saw no appreciable difference in strength after the trip. Also, I would hit the wall midway into the first day if I had a 2500 calorie deficit that was depleting my glycogen levels. So while I saw the report, not science about the 31 cal/lb I think it is a lot more complex when dealing with endurance activities.

[Bob Gross]

"4) altitude. If I understand this process correctly. Fat needs oxygen to burn. If that assumption is correct then higher altitudes will limit oxygen and thus the ability for fat to be used as effector for fuel."

With a tiny pulse-oximeter, you can monitor your body's blood oxygen saturation. If it is really going to hell, like 80%, then I could understand the effect on your metabolism of fat. However, if it stays relatively normal, like 95-99%, then there is no problem.

My blood oxygen saturation stays relatively normal unless I am at high elevation AND I am pushing hard.

–B.G.–

[David Thomas]

+1 on Bob's O2 thoughts. If you're short on oxygen, that will manifest in lots of ways before effecting your metabolism. Like Bob, I've tracked my blood saturation levels to 14,000 feet on land and to cruising altitude (7500-foot equivilant) many times. You should be 98-99% at home, 97-98% at North American BPing evations ( a few points lower for a smoker).

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