Burning body fat?

[Moondog55]

Here's a food question I am unsure about.
I am massively [ for me] overweight; and on my proposed amble around the Feathertop circuit next fortnite I want to minimise my carried food and rely to some degree on my stored body fat.
I'm not fit or conditioned so my MET won't be optimum.
I'll mostly be living off coffee and instant noodles, sardines and tinned tuna in oil and I'm wondering what the current guidelines for optimum fat loss per day is, reading gives me a wide range from a kilo a day to less than a tenth of that. I assume that the maximum loss rate includes a lot of water.
My gear is older and on the heavier side so I really want to cut down the weight of food and fuel I am going to have to carry to compensate for the old mans mattress system I need to let me get some sleep.
Ten years ago I did this walk in 4 days, this decade I think I'll need double that or maybe even ten days.

[crollsurf]

When I was a young adult, I went 2 weeks without eating, waiting to get paid. Wasn't hard actually. Your stomach shuts down and you just keep going.

At 62, missed lunch on the first day ski touring. Faded badly late afternoon, and I don't think I fully recover over the 3 days.

Everyone's different, but I wouldn't recommend dieting while hiking when older. Keep the energy levels up, and the exercise alone will shed some weight.

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[sandym]

There are a few medical studies where obese people were put on water and electrolyte diets for extended periods of time with no adverse effects. I think the longest one lasted a full year. What is the optimum guideline for fat loss - who knows? No-one, and anyone who claims they do does not understand the limits of science, particularly medical science. What we do know is that the human body is very adaptable.

It is possible to ramp up the mitochondrial machinery in your cells - mitochondria are the organelles within your cells that produce energy (ATP) - so that your body will generally use ketones for energy instead of sugar. Ketones are a by-product of fat metabolism. The caveat is that it takes people varying amounts of time to adapt to a ketogenic diet and really ramp up the ability to run on metabolised fats. The estimates for this vary from three weeks to three months to a year. YMMV.

Does it matter to you what the "optimum guidelines" are? How will you measure your fat loss while on the trail? If your fat loss exceeds "guidelines" what will you do? In other words, is knowing anything about "guidelines" going to change your behavior?

The food you are thinking about carrying sounds very heavy, and, even after you've eaten the fish you have to carry the cans. Is dehydrated meat/animal products an option?

Perhaps try and experiment before you embark on the Feathertop Circuit by eating the diet you plan to eat on your trip and see how you feel?

No matter what you do if you cut your calories massively, fat adapted or not, there are times when you will feel sluggish/fatigued. If you have sufficient mental toughness you can probably push through that.

[headwerkn]

I'll echo Sandy's comments. In my experience of generally erring towards low-carb/high-fat diets to varying extents over the past decade, your body will need a period of adaption before it's happy burning predominately fat (or more specifically, ketones) over glucose. Typically this is about 3-4 weeks, the period in between often referred to as 'carb flu' due to the feelings of listlessness and fatigue as both body and brain switch over to the different primary fuel source.

Of course there is a big difference between achieving this long term via a low carb or ketogenic diet that still more or less meets your daily calorie requirements, or simply running a calorific deficit over a shorter period of time. The later being pretty easy to achieve if you're doing a decent amount of bushwalking each day, regardless of whether you're eating a carb- or protein/fat-focussed diet. Really depends on what you're trying to achieve - saving food weight off your pack for a trip or to kickstart some personal weight loss?

Ironically hiking food has always been problematic for me staying consistently low carb, as yeah, fresh meat and green vegies aren't convenient or particularly lightweight when out on the trail for extended periods of time. You can try dehydrating your own veggies mix, maybe with a little gravy powder or similar for a bit of flavour, and make biltong or jerky for protein.

Alternatively just eat 'regular' foods, but smaller serves. Keep the museli bars etc. to one or two a day, replace the lollies and chocolate with dried fruit, etc. etc.

Either way, I'd also suggest experimenting at home for a few weeks before the trip to see how your body reacts. Bonking out mid-trip is rarely a good thing

[Son of a Beach]

I'll echo Sandy's comments. In my experience of generally erring towards low-carb/high-fat diets to varying extents over the past decade, your body will need a period of adaption before it's happy burning predominately fat (or more specifically, ketones) over glucose. Typically this is about 3-4 weeks, the period in between often referred to as 'carb flu' due to the feelings of listlessness and fatigue as both body and brain switch over to the different primary fuel source.

I second all that, based on my wife's experience (not my own). She's done a lot of research and went fully keto for a while (and intends to get back into it - very difficult when living in a house full of others who are not keto).

Here's what we did for an extended walk with our entire family, with ONLY her being (mostly) keto and the rest of us not-at-all keto:

Dinner

• 1 x Chicken curry
• 1 x Spag Bog
• 1 x Shepherds Pie
• 4 x Strive (varieties)

Breakfast

• 2 x porridge
• 1 x pancakes
• 1 x honey oat bars
• 3 x granola & stewed dry fruit
• 4 x bone broth

Lunch

• 7 x Wraps, crackers
  
  • Butter
    
  • Vegemite, peanut butter
    
  • Cheese
    
  • Cream cheese
    
  • Salami
    
  • Cucumber
    
  • Carrots
    
  • Snow peas
    
  • Dried tomatoes
• 1 x two-minute noodles
• 4 x egg?
• 4 x avocado?

Snacks

• 2 or 3 different scroggin mixes (packaged per-person, per-day)
• Hot drinks for kids - milo, stock, cupa soups
• jerky & billtong
• salt & vinegar peanuts
• papitas
• parmesan cheese
• Pork crackling
• Chocolate

Now you may look at that list and think "that's not keto!!!" and you would be right. But here's how we adapted it to only her being keto:

• She had only bone broth for breakfast most mornings, although she did have the same breakfast as the rest of us on the days when we had home-made granola and stewed dried fruit
• While breakfast was being prepared, she would boil two eggs (we can carry a lot of eggs, and they are easy to pack once you know how)
• At lunch time she would alternate between boiled eggs and avocados as well enjoying some of the cheese, salami and veges that the rest of us would have on our wraps/bickies
• At dinner time she would eat the same meal as us, except leave out the carbs (mash, pasta or rice) - similar to what she does at dinner time at home. Note that half of the dinners were home dehydrated meals, so easy to separate out the carbs. For the others... well... she just put up with having to have a few carbs on those nights.
• For snacks, she skipped the chocolate, of course

I'm no keto expert, and I'm sure that this is still not a 100% keto diet. But it was close-ish, and she had really good food for the entire trip, with very little in the way of carbs or sugars. Good amount of protein and fats. This system worked so well for our group that I've keep this list on file in case we ever do a similar walk again.

[Moondog55]

I might bake a dozen Tararua biscuits for lunches to add some extra calories then and toss in a couple of instant oats if I think I can stomach breakfast.
It's such a short walk and food is more of a comfort thing than a nutritional need when packing a spare tyre like mine

[sandym]

Tatarua biscuit? What is this thing you speak of?

[Neo]

Hi MD my two bob and it won't really work for bushwalking is to try fruit breakfasts and wander around all day. Only eat fruit until lunchtime and do a lot of general walking. Maybe add in lunch as the larger meal so small tea/dinner.

Edit and addition: overnight bushwalks I tend to eat less or smaller meals. Generally I start with coffee and a biscuit instead of breakfast most days of my life, love having leftovers for brunch

[Moondog55]

Tatarua biscuit? What is this thing you speak of?

Finger fart.
Tararua biscuit
Semi-sweet unleavened oat and wheat flour biscuits

[Moondog55]

Sandy I've yet to meet a freeze dried meal I can actually stomach eating since the army stopped making the tuna rice and peas available.
Although the side effects of that FD meal made sharing a tent somewhat uncomfortable
I've found small tins the easiest way to carry oily foods, the small empty tins don't really weight that much and I can drop the clean empty tins into the recycle drop-off at Mt Hotham on the way
past, if I feel malnourished I could visit the pub for a steak and salad lunch before heading to the start of the Razorback.
I just weighed an empty tuna tin and lid and it's 21 grams and while that is heavier than the packaging for a MH dinner it is 100% recyclable at only a 10 gram weight penalty
Now if we were talking about large tins of baked beans that might be a different matter, but I am taking the small 95gram tins of tuna or chicken and the sardines are 115g.
I tend not to eat much the first 2 or 3 days of a walk. Sadly I've not had a chance to do any real walking for a year and my white season was interrupted

[ggorgeman]

As I understand it (from exploring the ketogenic rabbit hole), you must get to a state of being fat-adapted if you intend to live off your body fat (and/or fat in your diet) as your energy source.

This involves "tuning" your system to burning fat as your body's energy source and for most of us who have been burning glucose (via a continuous stream of carbs >> sugars in our diets for the majority of our lives), the transition to becoming fat adapted can take weeks/months. As I understand it, even once fat-adapted, it isn't straightforward to switch back/forth between fat burning and carb/glucose burning.

I hope that little bit helps. There's a universe of literature, youtube etc that covers this area. Start with "Low Carb Downunder" - google and Youtube.

[sandym]

Moondog, I think a lot of the commercial freeze dried meals are bulked out with TVP and don't actually have that much protein in them. Not sure that many people can tolerate TVP without gassing out tent mates. Pretty rancid stuff.

[Moondog55]

Actually I'm OK with TVP, used it all my professional life and I still use the Vegan packets you get at the supermarket, but at 10% of the mince weight not straight

[CasualNerd]

I'm going to echo everyone else's comment on the fat adaptation - You need time and practice with this if you expect to efficiently burn body fat.

If you do it often enough your body seems to switch very quickly, but if you are intending to carry lots of carb heavy snacks it's going to be much much more difficult. I'd go as far as saying it would be better to eat nothing at all than filling the gaps with carbs, as you're resetting the whole cycle every time you get carbs in the system.

[Moondog55]

Interesting.
Seems to tie in with the year I lost so much weight while ski-camping. My usual track snack is actually a Mars or Snickers bar but even those have heaps of naked sugar.
I'll just have to see how I go

[headwerkn]

Moondog - look into the "train low, race high" concept. Basically low-carb adaption during training but then utilise additional carbs when doing big extended efforts. The idea being that your body is utilising more fat during endurance-type events but isn't limited by a lack of glucose required to maintain the upper end of anerobic output.

This was something I (mostly) used for several years for long distance running and triathlon with reasonable success, but I think it benefits more aerobic-based endurance efforts like bushwalking too. Being able to sustain multiple big day efforts with relatively limited amounts of convenient carby foods eg. museli bars, lollies/chocolate etc.

It's probably beyond the interests or needs of the average bushwalker, but there is a great book called "Training For The Uphill Athlete" that goes into all of this in gloriously scientific detail. Highly recommended if you're interested in improving your performance in the mountains.

[Moondog55]

When I ran and trained for running I did try carb loading a few times, but I had to stop running decades ago when I stuffed my back up at work.
I'm wondering where my traditional peanut butter and honey sandwiches fit in, back when I started bushwalking practically everybody made a few and used them for breakfast and lunch day one and two, Tupperware sandwich boxes were also popular, ditto rich fruitcake. Neither of which are lightweight but do have benefits in terms of concentrated killerjoules and ease of prep and eating

[ggorgeman]

When I ran and trained for running I did try carb loading a few times, but I had to stop running decades ago when I stuffed my back up at work.
I'm wondering where my traditional peanut butter and honey sandwiches fit in, back when I started bushwalking practically everybody made a few and used them for breakfast and lunch day one and two, Tupperware sandwich boxes were also popular, ditto rich fruitcake. Neither of which are lightweight but do have benefits in terms of concentrated killerjoules and ease of prep and eating

Cutting to the chase.... do some (lots of) research yourself via "Low Carb Down Under" and other eg Dr Berg on YouTube and you'll find that, if you modify your diet to become fat-adapted, your body can be fueled without carbs at all. Full stop! Your body uses ATP as its energy source and ATP can be produced from fats alone (stored fats and consumed fats). Veggies (careful re starchy ones) and salads will incidentally give you some carbs anyway. Side benefit is not just significant weight loss but significant benefits re metabolic health (not in the least limited to avoiding Type 2 Diabetes epidemic). Not wanting to be blunt but you need to invest some time researching this and your questions will be answered! Things can get trickier re hiking and camping for extended periods as food choices become complex. You'll enjoy the journey learning about this.

[Moondog55]

Yes to all of that except the answer to my original question isn't at all clear.

[ggorgeman]

Yes to all of that except the answer to my original question isn't at all clear.

To clarify..... your original question incorporated: "I want to minimise my carried food and rely to some degree on my stored body fat".

What I'm saying is that reliance on stored body fat for fuel is very complex; it is difficult for most of us to switch to fat burning as fuel, without an understanding of nutritional and metabolic processes. And a lot of time and effort to get to a fat-burning stage. And it's basically impossible to "rely to some degree on my stored body fat" because fat burning requires conditions that pretty much exclude carb consumption (from the likes of noodles etc).

[sandym]

Mate, you'll be fine. Remember Joe Simpson got dropped in a crevasse in South America, broke his leg, spent three days crawling back to base camp with minimal water and no food and made it out, not only alive, but went on to climb hard routes again.

I think you are over-thinking it. Humans are incredibly adaptable - although walking around the food court of any mall might disabuse you of this idea - but you'll have food, you'll have water. You might feel a bit weak but if you are motivated you'll be fine. Remember what Mark (or is it Marc?) Twight said "The mind is primary." https://www.nonprophet.media/

Many years ago on a two week ski traverse our food cache disappeared into a lake (long story) in the Purcell Mountains of Canada. We spent four days skiing out in tough conditions with no food. We were fine and broke trail every day from sun-up to sun-down while carrying glacier ropes etc. We sure did clean the buffet out afterward though.

You quote reading some information that says a kilogram a day or less than a tenth of that, which is under 100 grams is acceptable daily weight loss. Excuse my french but 100 grams is less than the difference in taking a dump in the morning.

It's nice to think in absolutes, but no-one, even the most fat adapted athlete burns only fat and the most carb-crashing junkie does not burn only sugar. It's a sliding scale, which is what the https://us.humankinetics.com/blogs/excerpt/the-crossover-concept cross-over point measures. Fat versus carbohydrate metabolism does depend on your overall diet, but is also dependent on the intensity of excerise.

You'll have a big pack on your back and you'll be going slowly so you will be metabolising fat.

[Moondog55]

I normally plan food calorie content to give me an adequate supply of kilojoules, based on my expectation of the weather and climactic conditions and my rate of ground coverage. Usually 3200 to 3600 Calories per day and up to 4700/5000 for white season.
IF there was an optimum rate of fat burning I'd recalculate and simply take less food.
In winter I usually try and stack on 5 to 10 kilos before hand and usually go home a few kilos down despite eating a lot of rice/beans/pasta/bread etc
I've got by with as little as 600 grams per day and as much as 2500grams per day although that minimum was less than ideal it was due to taking an extra amount of time to do a walk because of conditions at the time.

[Moondog55]

Yes I do often overthink stuff.
Also The Boss worries about me and I like to demonstrate that I'm not taking risks.
I'll be doing some food packing over the week-end, a lot of stuff that didn't get eaten over my white season.

[Neo]

A different idea, can you do a food drop at a half way point with all the goodies, then start the first half with minimal rations or meals? Then if it's too tough trying the initial way, whichever chosen, your backup is the drop with regular food and quantities.