Food for Nighttime Heat

Snickers.

Cheap, easy to eat. Tasty.

Sarah,
Two Snickers Fun Size is my current choice – 160 calories at 84/12/63 Cho/Pro/Fat.

But I'd really like to know what best fires the furnace from a metabolism perspective.

As long as you don't invite a 4-legged "guest" by keeping food in your tent.

If the bears don't get you, your dentist will!

Hah….very true! When I had my braces on I had to eat and rebrush my teeth. Often I just starved instead ;-P

I'm not an expert at anything, let along nutrition, but it might be a while before you get a reply from an expert nutritionist. Here's a suggestion:

Try those homemade Larabar recipes eveyone has been talking about in another thread, perhaps one with a pinch of cayenne pepper thrown in. They're dense, fatty, fulfilling, slow digesting, and the capsaicin in the cayenne increases metabolism raising the body temperature naturally, good things when you're cold. Cayenne helps with the circulatory system, lot's of people use it daily for homeopathic uses, a well functioning circulatory system never hurts when you're cold at night. Almonds (one of the main ingredients in Larabars) contain protein and fat, which I do know helps slow digestion, that can be helpful in the night, all that activity in the bowels (core) requires blood, blood is warmth. Only problem with dates found in Larabars is dates are a mild laxative, similar to prunes and figs, they could trigger your bowel movements in the middle of the night…bad. One potential problem I could see with Snickers is the high amounts of added sugar and cocoa content, it might spike your blood sugar, just a thought. I think anything calorically dense is going to help really, it's all about calories.

Eugene has some good advice. I have to admit I knew cayenne was good for you but I didn't think of it that way for that particular recipe – it was more of a taste thing.

You need more fat. That's what keeps us warm. A good rich hot chocolate made with Nido or something like that. If you don't want to drink then walnuts or almonds work well. Make sure there is some good fat in your dinner as well.

Edited to add…

This might provide some insight into glycemic index and such. I'm diabetic and have to have a carb snack at night. If I don't my blood sugar goes very low in the night and then my liver starts pumping out chemicals to counteract – thus causing me to wake with a high blood glucose reading.

I've learned, and this could be applied to the non-diabetic hiker, that having a bit of fat with my carbohydrate slows the blood sugar spike thus causing a more gentle rise over a longer period. In essence this would help keep you fueled and warmer in the night.

Greg provided some supplemental information to his original post. He said, in part, "When backpacking I get to sleep around 8:30 pm, but then get cold around midnight, to the point that I wake up shivering. This can occur in a 20 bag, on good pad, on a 35 night. If I then eat a couple hundred calories I can sleep for another hour or two before things repeat. Then, about 30 minutes before the 6 am alarm, it seems like my basal temperature plummets and very little can warm me up.

I just put these pieces together, after spending a year trying to figure out why quilts, sleeping bags, and pads were not keeping me warm. They were not at fault, I was.

I know I am running a calorie deficit though out the day 2200 calories for 20 miles over 10 hours, on average. I do not feel hungry or low on energy. I do notice an emotional "slump" around 2 pm, especially if the temperatures are above 70. I drink around a half liter of water an hour, depending time of day and temperatures.

I'm a 63 year old male, 5'9", 175# +/-, with managed hypothyroidism. I have good endurance, doing several 100+ mile trips a year.

My questions are: What can you tell me about metabolic cycles, sleep, and the optimal night-time mix of carbohydrates and fats to address this issue? Or what reading would be appropriate for a lay person to determine an approach? I'm as much, or more, interested in the "Why" than a prescriptive solution."

Greg,

If the heat your body generates matches the heat your body looses through your insulation you will be thermo-neutral which provides thermal comfort for any time period. In your case either your body is generating less heat than the average male, as defined by the EN13537 standard at 46 W/m2, or your sleeping system is generating less insulation than what is required for a 20 degree bag (6.85 clo which equals 1.06 m2K/W) I strongly suspect that feeling cold when sleeping is caused by your basal metabolic rate being abnormally low as a result of your hypothyroidism. This is a condition in which the thyroid gland does not make enough thyroid hormone; one symptom of this condition is a reduced BMR. Using the thermic effect of food to compensate is only a two hour solution.

I suggest that you have your BMR measured at any local facility that does indirect calorimeter tests. Many gyms use the simple handheld BodyGem to provide this test for about $50 and up. Once you know your BMR, you can easily determine the additional insulation you require to be thermo-neutral. It = (K * DT * A) / H is the heat conduction formula. Since K, DT, and A are constants for this problem, the amount of insulation you require can easily be calculated from your actual BMR. Alternatively you can just determine this value by wearing progressively warmer sets of insulating clothing with your sleep system to determine your thermo-neutral point. You can then estimate the clo value of the supplemental clothing you used to order a higher insulated sleep system. Alternatively you can just continue to use the appropriate supplemental clothing with your sleep system.

Neither the EN13537 BMR nor your unique BMR includes the post 1-2 hour thermic effect of foods eaten. A meal will provide a maximum thermic effect for the period 60 to 120 minutes after consuming it and then rapidly drop off. Your two hour sleep / eat again cycle is generating temporary extra heat from the food’s thermic effect but this is only a 2 hour benefit regardless of what mix of protein (biggest benefit), carbohydrates, and fat that you eat.

Thermic effect of food is the increment in energy expenditure above resting metabolic rate due to the cost of processing food for storage and use. A common number used to estimate the magnitude of the thermic effect of food is about 10% of the caloric intake of a given time period, though the effect varies substantially for different food components. In general, the typical thermic effect of protein is 20%–35% of energy consumed; for carbohydrate, this number usually falls between 5% and 15%; and for fat you can assume it is about the same as carbohydrates although some studies have found that fat has a lower thermic effect compared to carbohydrate while others have found no difference between the two.

Your “30 minutes before the 6 am alarm” maximum coldness is a result of two factors. The primary factor is that this is normally the lowest temperature for each day. Secondarily you are no longer experiencing any residual thermic benefit to offset your insulation deficit.

In summary, the thermic effect of food provides a maximum benefit for only about 2 hours. For a full night’s sleep benefit, add the incremental insulation you need to be thermo-neutral with your lower than average BMR.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC424000/

The average person needs 1800-2000 calories per day simply to maintain their weight while being sedentary. At 2200 cals per day you are under a massive deficit (hiking 10 hours per day) no matter how "not hungry" you feel. He is eating 200 calories for 2000-3000+ calorie workload. It will catch up with you sooner or later. The thyroid level needs to be monitored as his doc recommends. A 20 degree bag (rated for closed shelters) is not a 20 degree bag in an open shelter (tarp or other shelter not having 360 degree nearly to ground coverage).

A nighttime snack can be anything as long as it's not table sugar that might spike quickly. I doubt the carb/fat/protein mix makes a significant difference.

When a wide range of studies are looked at then the answer to this question is a little clearer.

http://www.jacn.org/cgi/content/full/23/5/373

pretty simple …

sugar for fast heat.
fats for long lasting heat.

Yvon Chouinard, one of the great Alpine mountaineers of the 1960's -1980's , was quite fond of drinking a shot of Olive oil right before bed. He claimed it kept him warm all night.

The "myth" for years has been that somehow all you have to do is eat fats and you will miraculously be warm. I realize the latest studies say proteins are more thermogenic, but don't see a ratio.

Most snacks will have a combination of carbs/proteins/fat that is good enough without the need to over-analyze the issue, especially when one is not eating enough in the first place.

"• Convincing evidence exists that protein exerts an increased thermic effect when compared to fat and carbohydrate. Evidence is also convincing that higher protein diets increase satiety when compared to lower protein diets."

Hi Greg. Do you wake during the night at home as well?

that's 440 calories of sheer amazing goodness. i try to have one for desert and one for breakfast when i'm out on longer trips :D

Thyroid meds have been checked and are spot on. And interestingly, according to the Doc, thyroid med levels are not in any way related to the amount of physical activity. They are much more fundamental than that. So "couch dose" is the same as "trail dose".

A resting metabolic rate is scheduled for later this week. Non-trivial, as I have to drive 2.5 hours one way to get it done.

Using protein as the most effective thermogenic snack might be met with a high protein bar. I'm looking for one I can actually eat and not gag.

Last, adding 6 ounces of down is by far the simplest and most efficient solution.

Backyard weather is stable, calm, and drifting towards 32° at night, so sleep system tests will continue.

Thanks all.

"Using protein as the most effective thermogenic snack might be met with a high protein bar. I'm looking for one I can actually eat and not gag."

Greg,

Another approach might be to mix up some powdered chocolate milk, add 1/2-1 oz of whey protein powder to it, then drink half before crawling in your bag and sip the other half during the night. You'd be taking in in excess of 20 grams of high quality protein in a form that should be way more palatable than some yucky protein bar. They're all pretty disgusting, IMO.

Resting Metabolic Rate

Got tested and I'm about 15% below "normal". So it's no wonder that I am sleeping cold. No amount of daytime food will carry me through the night. The furnace is just idling to low. Now I know.

So, a few quilts and bags will be coming up for sale as I move into gear that is "Typical -10°" for comfort.

Thanks all for comments and suggestions, and especially to Richard Nisley for the science and the suggestion of RMR testing.

Greg,

It was an interesting puzzle for us to work on. Thank you for sharing all of the relevant information needed to make educated guesses as to what was happening and how to address it. It makes helping people even more rewarding when they express their appreciation.