Basic questions about metabolism

[Saz94]

OK so

If I eat less than usual on one day, and my energy is worse, is that due to eating less or is it just a coincidence? Because doesn't it take quite a while for the body to turn your food into energy anyway?

I'm trying to lose weight, but my brain is saying "go eat a packet of crisps, it'll boost your energy" but surely that is nonsense because it would take several hours to digest the crisps into energy?

I ate plenty yesterday (and all other days...) so surely there should be some energy from yesterday's food available to me? Unless I've already used it of course.

Basically I guess the question is, on any given day are you using the energy from the previous day's food, or from today's food, or what?

I've been trying to Google it but that's just making me even more confused. One website says food is digested within 24-72 hours, another one says 2-3 hours.

I think it varies by food type...

So, how quickly does energy become available (not just the first available energy from it, but the majority of the energy) from the following:
- carbohydrates?
- protein?
- fat?

- - - - -

And now I'm even more confused, as I've just read this:

"Your body can only use about five percent of absorbed fat for fuel by converting it to glucose. Your liver absorbs the rest of the glycerol and uses it to assist in breaking down glucose for energy."

So does that mean that, for example, when I spread butter on my toast, I'm only actually going to get 5% of the calories of energy that the butter is supposed to contain?

And then what happens to all that glycerol?

- - - - -

Bonus question:

What about vitamins and minerals from the foods?

I.E. If I feel slightly better/worse when I have more of a particular vitamin or mineral, would I feel slightly better/worse on the day that I eat something high in it, or on the next day?

Trying to figure out what makes me better and worse is so confusing!

 

[Jonathan Edwards]

By and large your ability to make use of energy has nothing much to do with what you eat at the time, or that day or the week. Most of us have enough energy stores to last a fortnight at least. We like to keep topped up with intake every day and use energy stored as glycogen in the liver rather than dipping in to fat stores. If we go low on glycogen stores we feel hungry but we can still produce energy.

I personally do not think the 'lack of energy' PWME feel has much to do with actual lack of energy in the sense of ATP. When a normal person wakes up n the morning they feel 'full of energy' but they are actually low on glycogen energy supplies so they eat some breakfast.

 

[Amw66]

It's what you eat. All calories are not equal
Given issues with glycolysis, carbs don't seem a good idea , but finding the balance can be difficult.
Low GI and increase in protein ( females from research seem.liklier to be using aminos for fuel) may help.
Keto didn't work for us - seem to have issues with fat.
Cutting out beige carbs works.

 

[Peter T]

I find in the short term eating a lot means less energy.

I have assumed without much justification that the energy required to digest a large meal can trigger PEM. The time I need to be particularly careful is Christmas, but I also have a set of neighbours whose wonderful hospitality is particularly problematic. However in most situations I can not reliably distinguish between the demand of a social event and the demand of digesting a large meal. Given the energy demands of preparing and eating food I usually end up eating only one or two larger meals a day, rather than three or four smaller meals. I find this unhelpful in terms of energy levels.

In contrast short term fasting, generally not intentional, results in having more energy and feeling better. It generally happens when I am worse and am not able to fit getting a meal into the available energy or have particularly bad nausea or something essential takes up all available activity time. So it is not clear what are the important variables: rest, restricted activity, pacing or fasting.

In patient forums there are often posts advocating regular short term fasting, but I have not followed up on any of the ideas.

[added - although I have identified a number of food intolerances (gluten, caffeine and alcohol) the above pattern could also relate to unidentified further intolerance(s).]

 

[wigglethemouse]

I have to have food at very specific meal times otherwise I crash. It's not pretty. A1C, insulin, and glucose tests perfectly normal. Perhaps ME can affect Glycogen storage in some people. Or as some have identified, Leptin, the hunger hormone, is screwed up in a subset of ME patients. Or there is some sort of circadian clock at work. I've seen a few threads over time from others where food consumption is very important for stability, especially in a downturn.

 

[beverlyhills]

Partial sublingual absorption - your saliva has amylase so you will get some glucose - not a lot. It is not necessarily Pavlovian.

 

[shak8]

Just eat. A balanced diet, lots of vegetables. Food is meant to be enjoyed, savored.

It is nice to know that your pooh is from food ingested 48 hours ago, roughly. So if you're constipated, you didn't eat enough fiber and water or took an extra dose of opioid, two days prior...roughly.

Simple carbs, like white rice, white bread (the inevitable soda cracker when you're sick) are so easily digested, as beveryhills said, digestion starts in the mouth. Meat takes much longer to digest. Most people get far too little fiber. High fiber and low red meat diets can prevent colon cancer, a fairly common disease.

But don't fuss, enjoy, eat what you should be eating, a balanced diet, not too much carb, not too much saturated fat (like butter), lots of vegetables, pulses (beans), fruits as sweets. Avoid simple sugars is good. Avoid getting fat is a longterm good. Do what you can each day to move your body.

Stress causes fat deposition and raises blood sugar (so it's bad, long term stress). Don't stress out out eating. Getting adequate sleep also fights putting on weight.

To lose weight, start your meal with vegetables. You may find yourself eating less of the main course because you are full. Your stomach needs thirty minutes to send the brain it's satiety (I'm full) message. So eat as slowly as you can. If you are still hungry (you've gotten that mmmm, it's good, dopamine reward of delicious food and you want more, more, more) just go at the vegetables again or eat a small piece of cheese or fruit. Be French about it.

Now end of lecture. And no, you can't tell the next day if you've had a lot of vitamins.
Disabled nurse w/ uni course in nutrition.

 

[Trish]

That all sounds like good common sense that is fine for healthy people who don't have food intolerances, IBS, constant nausea, etc. and have the energy to prepare food, and finances to eat well, @shak. Life isn't always that simple.

Stress causes fat deposition

Really? Evidence?

To lose weight, start your meal with vegetables.

Again, fine in theory, if you have the energy to prepare them and your symptoms allow...

 

[lansbergen]

Ignore the disease process and everything will work like in healthy people.

That all sounds like good common sense that is fine for healthy people who don't have food intolerances, IBS, constant nausea, etc. and have the energy to prepare food, and finances to eat well, @shak. Life isn't always that simple.


Really? Evidence?


Again, fine in theory, if you have the energy to prepare them and your symptoms allow...

 

[Barry]

I personally do not think the 'lack of energy' PWME feel has much to do with actual lack of energy in the sense of ATP.

I tend to think that 'lack of energy' with regards to pwME is a misnomer, though popularly understood ... and misunderstood (I'm obviously not including you in the latter!). To me her problem seems much more related to a reduced rate of energy delivery to the parts of her body that need it (which I presume is just about everywhere). i.e. Lack of useful power seeming to be key to her problem. As if there might be some obstruction in her energy delivery / utilisation mechanisms, or maybe something diverting the energy to somewhere else before getting to where it is supposed to. My wife can keep on doing stuff for quite a while but much slower than others, and progressively gets slower and slower.

 

[Amw66]

I would agree Barry. It's s energy delivery. The difference between power and energy - as only an engineer can appreciate.

 

[Jonathan Edwards]

To me her problem seems much more related to a reduced rate of energy delivery to the parts of her body that need it

I think that would be included under my scepticism. Everything I hear about ME sounds like some sort of signal telling the parts of the body not to use energy. I think it very unlikely that there is a problem with energy delivery - which in simple terms is supply of glucose most of the time. Blood sugar is normal.

 

[Jonathan Edwards]

digestion starts in the mouth

Just a small point on this. If I remember rightly from school biology salivary amylase works at alkaline pH (most pH) and takes about an hour to generate reasonable amounts of glucose from starch (when the iodine went purple). Food is normally in the mouth for about ten seconds and then hits a very low pH in the stomach which will destroy the amylase. So my biology teacher and I agreed that it is not really credible that salivary amylase contributes to digestion. To me a much more plausible reason for having salivary amylase is to dissolve the starch stuck on your teeth after meals to keep your mouth clean.

 

[lansbergen]

Everything I hear about ME sounds like some sort of signal telling the parts of the body not to use energy.

Or a receptor disfunctious so the cells can not work properly.

I think in my case the a7nAchR plays a big rule.

More so since I know this receptor is on the musclulair site of the neuromusculairjunction.

The immune modulator I use is a allosteric a7nAchR modulator. It reduces the pain in 10 minutes and it gives a deep relaxation.

So not Myasthenia gravis as you and I concidered but a receptor problem.

 

[feeb]

I think it very unlikely that there is a problem with energy delivery - which in simple terms is supply of glucose most of the time. Blood sugar is normal.

Having low blood sugar also feels very different to PEM and ME, you can tell the difference in yourself between them. Of course, you can have both simultaneously, but you can fix low blood sugar in 15 minutes by just putting some glucose into your body - but it won't fix PEM or ME more generally.

Stress causes fat deposition

Really? Evidence?

I thought the relationship between long-term stress and fat gain was quite a common observation in the literature and quite widely accepted? e.g. https://www.cell.com/cell-metabolism/fulltext/S1550-4131(18)30190-6

 

[Barry]

I think that would be included under my scepticism. Everything I hear about ME sounds like some sort of signal telling the parts of the body not to use energy. I think it very unlikely that there is a problem with energy delivery - which in simple terms is supply of glucose most of the time. Blood sugar is normal.

I suspect it is more my inadequacy at explaining, and my misusing the word 'delivery'. I was really meaning energy getting to where it needs to go to at a slower rate than is required, for whatever reason. Be it inadequate availability; or available but control / signalling mechanism broken, so the body's need for energy at a certain rate not being fulfilled by the controller. e.g. Akin to driver's request for power via accelerator pedal being incorrectly processed by ECU, such that the engine's throttle not opened enough to match. Could be a problem with the ECU itself; or the signal connections between pedal and ECU, or between ECU and throttle actuator; or a problem with the throttle actuator, or throttle; etc.

I was alluding to this when I said "As if there might be some obstruction in her energy delivery / utilisation mechanisms", which "utilisation" was hoping to broadly get across.

And yes, from what you are saying it looks like the energy is available, and something going wrong at some point further downstream from that. The crux being where that point actually is. The more parts of that chain that can be identified as are working, up and downstream, the tighter we can hopefully close in on where the problem really is. But I do appreciate it is hugely more complex than cars and engines. If only humans came with similar self-diagnostics to modern cars!

I've pondered for a long time since my wife got ME, that her diet is still pretty normal so energy intake is normal. But somewhere along the energy-processing chain her energy uptake is not.

ETA: When it speak of 'delivery' I was really meaning 'delivery at the point of use'. So for the car it would be atomised fuel in the engine cylinders. (Though as I write that I realise oxygen delivery at the point of use is also key).

 

[Trish]

I thought the relationship between long-term stress and fat gain was quite a common observation in the literature and quite widely accepted? e.g. https://www.cell.com/cell-metabolism/fulltext/S1550-4131(18)30190-6

Interesting. Thank you.

 

[WillowJ]

Sports medicine and biology have a lot to say about different kinds of foods and how quick of energy or how sustaining they are.

Simple carbs (sugary foods, crisps/chips, crackers, etc.) provide quick glucose.

Complex carbs provide stored glucose (carbohydrates are more or less long chains of sugars).

Fats also store energy, and there's an alternative process to get this that doesn't rely on glycolysis. Ditto for protein.

I think in ill people it will be different depending on what's wrong. Some people with some types of dysaunonomia, gastroparesis, or other GI problems tend to have reduced energy and/or increased illness after eating.

Some people feel better or worse with different foods and this will be highly individual (I feel less nauseated if I eat carefully selected starches, for example--but other people have completely different experiences).

Blood carries stuff around, but it drops it into the tissues. So if we're using up glucose fine (even if we're not using the main pathway for it that makes loads of ATP), there's not going to be a blood sugar issue as far as I can see, even though we may have an issue with how glucose is used to make ATP.

I'd say eat whatever makes you feel better (from a health standpoint). Track it long term as well as short term if you can.