So, I got invited by a couple of friends to go hiking and doing some "survivalist stuff". I was never the most resilient person so was kinda unsure, then I decided to try and "test" myself a little bit and then give them a response.

I bought some of those emergency dried rations that says you need to eat every 6 hours and I'm only eating them throughout the day.

But even though it has all the calories one would need, my body feels weak and trembling. I don't feel bad in any shape or form, just weak and hungry (and a light headache that I feel when I skip meals). I tried to fool my body by drinking water and/or juice, but the sensation is still there.

Are there any tricks on fooling my body that I'm full?

Like swallowing those soluble vitamin C tablets, drinking sparkling water or eating something really dry like smashed cracker biscuits?

  • 3
    Whats you "fitness level", i.e. how often do you work out? Especially cardio, like runnning/cycling etc. for more than an hour or two?
    – Max
    Commented Nov 16, 2022 at 15:44
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    I suspect those bars don't go as far as you think. Comparable ones I've had have only been about 300 Cal each so 4 of those in a day adds up to rations on which you can survive for a while but very roughly half what you need to thrive - or even less if you're doing lots of physical stuff .
    – Chris H
    Commented Nov 16, 2022 at 20:27
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    Good job on trying something new and unknown. Many more people are afraid of the outdoors. When there is a change in eating schedule, many people get a headache. So keep up what you are doing and the headache part may go away and maybe the physiological effects. I do not know you at all, but I do know severe anxiety among younger people has skyrocketed. I know for certain that some of the outdoor activities I did as a kid challenged me to control anxiety. eg: Freaking out will only result in the river stealing my canoe. Relax to learn how to meditate. Meditate to learn how to relax.
    – rjt
    Commented Nov 17, 2022 at 3:28
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    I have never done anything I would call "survivalist", but I've done a lot of hiking and camping. I find the idea of limiting calories in order to complete an unusually large workout odd (and an all day hike almost surely is unusually large). If anything I would expect to plan to overeat. In terms of the weight of your pack, calories are extremely light (compared to, say, water). Even a kilogram of something like flapjack or biscuits is more food than you need for a day. Don't suffer unnecessarily. Commented Nov 17, 2022 at 10:49
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    "But even though it has all the calories one would need, my body feels weak and trembling. I don't feel bad in any shape or form, just weak and hungry (and a light headache" that sounds like "Non-Diabetic Hypoglycemia After Exercise" newhealthadvisor.org/hypoglycemia-and-exercise.html Commented Nov 17, 2022 at 12:50

6 Answers 6


I've used a few methods for this (being a larger guy who would backpack with smaller individuals). The biggest thing I've learned is that the mental aspect matters as much as the nutrition. Here's the ones I can attest to personally:


I list this first because you don't have to bring it with you! Like acupuncture, the better known of the pressure point techniques, acupressure provides stimulus to nerves to achieve desired results. I've used a point on the back of my knee, slightly off center toward the opposite leg. It's not listed on this resource, but more hunger points can be found here. It doesn't matter if it's real or perceived. Perceived improvement IS real improvement.

More filling food

Calories are the main thing to account for when you're remote for extended periods of time. If you spend time in less-developed areas, you quickly learn the foods that people use to feel fuller than their calorie count would indicate. The added benefit is that they are often cheap and shelf-stable. Things like ramen, oatmeal, grits, and potato flakes fit the bill. These line up better with proper meals than they do with snacking, which is another thing I'd encourage. (Update 1) (Update 2) Easy access to water and fire means you can add weight to this food while also making it hot...


It's amazing how much hot food/drinks matters, especially in the morning. But this is mental more than it is biological. Hot food means control and safety, even if it's hot out. Many people think bringing a granola bar to eat for breakfast will be quick and provide what they need, but I feel much fuller if I eat the equivalent calories of hot oatmeal. (Score another one for oatmeal here.) If you're used to coffee in the morning, bring coffee (or even drink hot water to keep the routine in practice).


You don't have to be diabetic to feel the effect of blood sugar changes. I never intentionally do bushcraft or backpacking without an emergency fun-size packet of M&Ms. Little space, low weight, big impact. 3 hours of fishing with no fish and feeling down? Eat a single M&M, get motivated, and fish for another hour. If your body can't handle the added sugar, bring PLENTY of natural sugars in the form of dried fruits. Just a little at a time, don't spike your blood sugar! (Update 3) Same thing goes for powdered drink mixes. A little mix adds sugar to standard water, while also adding a ton of flavor...


Flavor is mental. If it's possible, opt for pre-flavored options. I've mentioned oatmeal several times, but it provides more mental motivation if it's apple cinnamon oatmeal or has chunks of dried fruit in it. Flavor matters more than texture, but texture variety also happens trick your brain into thinking you've got a ton of options. I dehydrated red pepper strips and toss them in with trail mix. I don't like unsalted nuts, but adding a fresh flavor to them helps balance out the typically sugary or salty trail options. If you bring ramen, only use half the flavor packets; you can use the flavor pockets on hot water to trick your brain into thinking it's food. I bring a packet of dehydrated beef stroganoff (my preferred dehydrated meal) with me when I go backpacking. I save it for the last day, unless there's an unexpectedly rainy or snowy day. The flavor picks up even the lowest of spirits. It's also worth considering that some meals don't taste good cold (e.g. potato flakes), but sometimes you can't heat up your water for dehydrated meals. Learn your wild herbs. Adding wild onions or garlic to blah food goes a long way.


Even if I'm alone, I'll often remark how "this time isn't as bad as that one time." Don't let horror stories get you down. Let them remind you of the gratitude you have for being prepared. If it's your first time missing more than one meal and you have several days to recover before going out, try fasting. Your first night on an empty stomach sucks. Your second night sucks less, not more. Why? You know what's coming. It also helps to separate the deep-seated instinct that hunger correlates to lack of control. Everybody gets the shakes when they fast. The mental-emotional warfare follows the shakes. Knowing you've gotten through it before makes it so much easier to push that little bit further.

Update 1

There's no substantive difference in calorie burn between frequent eating and spaced out meals. That said, normalcy is powerful. If you snack normally, snack while out. If you're foraging, snack on it. If you normally eat regular meals, try to eat regular meals. Experience can dictate what works best for you.

Update 2

Don't grind your own flour from acorns. If you find corn to grind cornmeal, you're no longer separated from civilization. Grinding meal/flour is only advantageous for complete backwoods living. You're better off learning wild edible foraging than rustic milling.

Update 3

Intake added sugars in moderation. Don't cause blood sugar spikes. Simply compensate when needed, such as when needing focus or energy to get to a known win.

  • 10
    Another point, drink some liquids. We often under-do our hydration. Sucking a hard boiled lolly can encourage saliva flow too.
    – Criggie
    Commented Nov 17, 2022 at 0:12
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    "Constant snacking wastes calories." Can you elaborate, specially since you put emphasis on that? There is no metabolic advantage or disadvantage in different eating frequencies, be it intermittent fasting, 3 meals or constant snacking. All have their pros and cons but it comes down to calorie intake. Especially with long exercise like hiking the whole day I would argue for a more "constant snacking" approach. It reduces the risk of "overeating" and storing the rest in fat and then falling into a low blood sugar dip.
    – Max
    Commented Nov 17, 2022 at 14:14
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    Sugar is NOT helping if you want to suppress hunger. Quite the contrary. Sugar causes large spikes and dips in blood sugar which in turn increase the feeling of hunger. The chocolate bar for emergencies is a good idea, other than that DO NOT rely on sugars. The crash will be worse than before! en.wikipedia.org/wiki/Reactive_hypoglycemia
    – Max
    Commented Nov 17, 2022 at 14:22
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    Careful with acorns; you'll probably want to get rid of the tannins, which is hard (requires prolonged soaking).
    – wizzwizz4
    Commented Nov 17, 2022 at 16:19
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    @Max: Sugar is fine during and after a long effort. I definitely get the effect you're talking about if I eat too much chocolate while sitting in front of my computer. But during long distance treks, bike tours or skateboarding competitions, I can eat 75g of pure sugar every hour, all day long, without any noticeable spike or dip in blood sugar. Commented Nov 18, 2022 at 19:31

There is a saying in cycling that the best post-ride meal is "a bottle of (sparkling) water and a couple of sleeping pills. You need to loose some weight." While not very healthy, the point of the statement is: You can trick your stomach for a little bit with the water but then need the sleeping pills for when actual hunger kicks in and can't be put off anymore. My experience on longer rides is the same: If I run out of food and feel hungry, I can down the rest of my water but that'l just help for a couple of minutes. Then I'm hungry and bloated...

So basically there is no easy solution if you are actually hungry. But there is a difference between actual hunger, i.e. measureable low blood sugar, and the feeling of hunger usually caused by habit or eating other foods that encourage appetite. I'll try to address both.

The "trembling and weak" part suggests that you actually are low on blood sugar and aren't getting enough calories. I'd suggest you double check your calorie consumption and how much you actually eat. As someone said in the comments, those emergency rations might not get you as far as you think. So you might just be eating too little. But even then you can live on a calories deficit without feeling hungry. You "just" need to train your metabolism. Without regular cardio training, you body will prioritise metabolizing you glycogen storages in your muscles and relies on regular food supplies to replenish these. The body won't start burning a significant amount of fat before all those glycogen reserves are used up. For untrained people that is somewhere around 30 mins to an hour or so depending on the exercise. At this point the body burns fat instead of glycogen to sustain you but this is a couple of orders of magnitude less efficient and you will start to feel weak, start trembling and lose concentration. This is called "bonking" or "hitting the wall" in sports. Regular cardio workout will train your body to start burning fat earlier to supplement the glycogen (and unless you are a pro athlete or severely underweight you always have fat to burn). This makes your glycogen reserves last longer, keeping your blood sugar at decent levels for longer and you won't feel as hungry. And this isn't only exercise related but will also help out on the day to day, just on a smaller scale because you aren't burning calories as fast. But "regular cardio workout" might not be the easy trick you were looking for ;)

Now for the perceived hunger that is a bit more difficult as this will usually depend on your eating habits. I've found, the easiest way to regulate hunger is to cut all sugars and this includes juices and other drinks with lots of sugar and to a certain extend, heavily processed foods. Sugar tends to cause large spikes and subsequent dips in blood sugar levels which in turn leads to increased appetite. If you skip sugars and cover your calories with "healthy" meals, your blood sugar curve throughout the day will be much "smoother" which should in turn lead to less appetite and less cravings for more immediate sugars caused by the large dips. Personally, whenever I cut the sweets from my diet, I can feel the effects within about a week: less cravings for sweets, less appetite and inherently smaller portion sizes.

So basically with regular exercise and a proper diet you will be able to stretch out feeling hungry.

While writing I did actually think of a couple of other things:

Carrot sticks, bell peppers and cucumbers have a good calories to feeling stuffed ratio. But then again why not bring more food? Same goes for water etc. is there some limitation on your hike?

Also caffein, nicotine and ephedrine or methamphetamine can very effectively suppress hunger for some time, but this is turning down the more unethical road and I would not recommend!


I suspect those bars don't go as far as you think. Comparable ones I've had have only been about 300 Cal each so 4 of those in a day adds up to rations on which you can survive for a while but very roughly half what you need to thrive - or even less if you're doing lots of physical stuff.

An example sold as survival rations are these on Amazon. They say 3600 Cal will last you 3 days. As emergency rations maybe just about but you'll be hungry - acceptable in an emergency. For regular life that's nowhere near, let alone with moderate exercise as well.

A typical adult male needs about 2500 Cal/day to maintain bodyweight, easily reaching over 3000 in someone tall who exercises regularly (I reckon 3200-3400 for me, on days when my only exercise comes from commuting by bike).


If I understand correctly, you are testing how well you do on freeze-dried meals in your regular environment. But when you go outdoors things will be different: you will be distracted with activity and new experiences and will have less time and attention for feeling hungry.

As others have noted, you do not really need to eat less calories either, because food is not that heavy so you can pack what you need. Ask you friends what they pack. You will need calories-rich and also salty food because you will likely sweat a lot more.

  • 3
    I've you're using commercial freeze-dried meals, you'll be getting more than enough salt. "Meal replacement bars" are another matter and that's what I suspect he OP has.
    – Chris H
    Commented Nov 18, 2022 at 10:54

Those rations have a the calories but not the same macro-nutrient breakdown you are used to, or they just have far less carbs/sugar than you are accustomed to.

and a light headache that I feel when I skip meals

This is commonly called "low blood sugar", but it really isn't (unless you are diabetic). You can test your own blood with a glucometer to prove this to yourself.

In other circles it's known as keto flu, it will often present early on in keto diets or fasting. It's just your body not being used to having to rely on burning your body's built in fuel, fat, in large quantities. I'm not being poetic here, by "used to" I mean that you do not have the enzymes in your cells to handle going without eating/eating fat/protein dense rations. With enough body fat is possible to go many weeks without eating at all.

The good news is that this is really easy to train for, and may actually be one of the most healthy things you can do to your body. You must become metabolically flexible. This process takes about 2 weeks and strategies to make it easier are well documented in keto/fasting community. Once you make it through, many people often find they can go from waking up until 2pm without ever thinking about eating, their bodies just burn stored fat. Another upside is that your brain functions more clearly as a fasted state promotes alertness via hormones. Think of this effect as the opposite of "after dinner lethargy".

Some ways to make it easier

  1. Stay hydrated
  2. Lots of salt (reducing carbs immediately allows you to start flushing salt, this thought be be a main source of "fasting headache")
  3. Get proper sleep
  4. Some people find it easier to ease into it, reducing carbs to "near zero", but over a one week time span. Others find it easier to tough out 2-3 hard days by going cold turkey.
  • Max explained a lot of this very well also in his answer both the cardio training and avoiding sugar both help you get more enzymes and body chemistry for burning fat. Sugar also tends to erode will power because on how it is absorbed, and how it affect hunger hormones.
    – Zak
    Commented Nov 20, 2022 at 19:49

Having gone through similar things on occasion on cycling trips - as well as unexpected end-of-outing slowdowns - I think you are asking the wrong question.

You don't want to "trick" your body into feeling full. You want to provide it enough long term energy for a day of strenuous physical activity. If losing weight is one of your goals, do that on another day.

Some background from my experience, having that happen on several occasions on multi-day 100km+/day cycling trips (with a 15-20 kg pack load, not on a road bike):

  • I come back much fitter from those trips, but also gain 1-2kg, easy. I probably run at 3-4 Kcal - basically it's a license to eat as much as I want.

  • Energy drinks and energy bars have a negligible effect, in my case. Once I "hit the wall", I stay extremely low on energy. I get cold, my speed drops and I have to limp in the rest of the day. More proper food will avoid the problem, and proper food + rest would probably provide a temporary fix if it starts. Sports nutritions stuff? Not so much.

    • I don't have diabetes myself, but my parents had pre-diabetes and hypoglycaemia, respectively. Maybe that's why I don't react all that much to sugar stuff once I reach exhaustion? Dunno.
  • The best way I found to store up on long term energy is to eat a very large, carb-heavy breakfast. Ideally, if you could eat a large plate of pasta in the morning. Failing that, I found that North American pancakes do a good job. You don't have to slather on the butter or syrup, but eat several. I am sure sure you can find better pointers than this around, by experienced athletes, but the point is prep for proper fuelling, don't try to play tricks.

    • In a camping context, regular noodle and pasta are actually pretty good - they are super lightweight and quite cheap. Tasty at breakfast? Not really. I typically add butter and cheese to give them some taste.
  • (after checking your medical circumstances: ) On the other hand, if you want to prep up for low food/survival days, you can do occasional single-day fasts - wake up, don't eat all day, drink lots of water and break your fast the next day - (I usually have to take headache medications). Just don't expect to be running marathons during those days. Yes, you will feel hungry but I personally have never hit "the wall" while on a fasting day. I do believe that that experience would serve me well if I was put in a survival context without food, but I would be cautious on expectations of being able to perform heavy extertions. Oh, and don't expect overmuch weight loss: you lose a lot on a 1 day fast, but it comes back very easily.

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