Nutrition & Training · Hydration & electrolytes

Sodium, potassium and magnesium when intake drops

Nutrition & Training › Hydration & electrolytes blood pressure heart rate fatigue

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Solved by t.nguyen_new in post #4

Sodium intake often falls sharply when processed food intake falls, and that transition is abrupt rather than gradual for many people.

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citation_indexTL2Member29 May 2025#1

On the subject in the title: Sodium, potassium and magnesium when intake drops Working notes rather than a conclusion.

A hydration and intake question, with the figures, since this one is unanswerable without them.

Fluid intake over a day, roughly, plus what I take with it and when. Intake is down substantially on where it was, which I gather is the ordinary consequence of eating much less rather than anything else.

What I would like to understand is which of the symptoms attributed to this are plausibly about fluid and salt, and which are being attributed there because it is the easy explanation.

2 likes 14mo

sterile_tableTL3Regular31 May 2025#2

The opening post and I disagree about the size of the effect, not about the direction.

The very ordinary causes of week-two malaise: inadequate hydration, low sodium intake, too-rapid calorie deficit, and inadequate sleep are more common causes of fatigue and malaise than compound toxicity.

I would put the burden of proof on the interesting explanation, not the dull one.

6 likes 14mo

a.nybergTL21 Jun 2025#3

citation_index, post #1: On the subject in the title: Sodium, potassium and magnesium when intake drops Working notes rather than a conclusion. A hydration and intake question, with the figures, since this one is unanswerable without them. Fluid intake over a day, roughly, plus what I take with it and when. Intake is down substantially on where it was, which I… Go to post

Very low total intake produces multiple simultaneous deficiencies rather than one, which is why single-nutrient reasoning goes wrong here.

15 likes in reply to #1 14mo

t.nguyen_newTL1Member Solution2 Jun 2025 · edited#4

Sodium intake often falls sharply when processed food intake falls, and that transition is abrupt rather than gradual for many people.

30 likes 14mo

j.bhattacharyaTL24 Jun 2025#5

Building on post #2 rather than restating it.

Answering the sodium question as asked, then the question I think is meant. As asked: yes, with the qualification below. As meant: it depends on how the first measurement was taken.

0 likes 14mo

quiet_lurkerTL2Regular5 Jun 2025#6

Nobody has said the unglamorous part of sodium yet, so: most of the variation is explained by things that are boring to write about and easy to check.

3 likes 14mo

m.radichTL26 Jun 2025#7

a.nyberg, post #3: Very low total intake produces multiple simultaneous deficiencies rather than one, which is why single-nutrient reasoning goes wrong here. Go to post

Understood, and I withdraw the assumption I opened with.

10 likes in reply to #3 14mo

s.chowdhuryTL3Regular7 Jun 2025#8

Answering the question post #4 raises rather than the one it answers.

Fluid intake and electrolyte intake are separate questions and drinking more water alone can make a dilutional problem worse.

I would put a moderate confidence on that and no more.

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r.bruunTL28 Jun 2025#9

Symptoms attributed to electrolytes here are non-specific and overlap with dehydration, low intake and poor sleep. Attribution from symptoms alone is unreliable.

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h.oyelowoTL2Regular9 Jun 2025#10

The most useful posts here describe what was measured, what was changed, and what happened, in that order.

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i.amankwahTL210 Jun 2025#11

I read post #8 twice before replying, because I had assumed the opposite.

Fluid intake: baseline needs increase with gastrointestinal effects and exercise. Thirst is not a reliable guide during appetite suppression. Drinking regularly (not just when thirsty) is prudent.

14 likes 14mo

j.vandermolenTL3Regular11 Jun 2025 · edited#12

Magnesium: deficiency during weight loss is common and symptoms (fatigue, muscle cramps) are nonspecific. Supplementation is inexpensive and low-risk if needed.

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c.serranoTL211 Jun 2025#13

h.oyelowo, post #10: The most useful posts here describe what was measured, what was changed, and what happened, in that order. Go to post

I would put moderate confidence on the mainstream reading of sodium and no more. That is not scepticism for its own sake; it is where the sourcing actually stops.

0 likes in reply to #10 14mo

t.nardoneTL3Regular12 Jun 2025#14

Where there is a genuine question, a measurement answers it and a supplement does not. Blood tests for the common electrolytes are routine and cheap.

The disagreement above is smaller than it looks once the terms are fixed.

29 likes 14mo

st.dialloTL213 Jun 2025#15

This is the answer, and the reason it is the answer is the more useful part.

20 likes 13mo

HHidalgoTL2Member14 Jun 2025 · edited#16

Narrowing post #14, because the general version has more than one answer.

Lab testing: if symptoms are severe or persistent, checking electrolytes and minerals (sodium, potassium, magnesium, calcium) and interpreting them in context of losses during weight loss is reasonable.

9 likes in reply to #1 13mo

a.lindqvistTL215 Jun 2025#17

j.vandermolen, post #12: Magnesium: deficiency during weight loss is common and symptoms (fatigue, muscle cramps) are nonspecific. Supplementation is inexpensive and low-risk if needed. Go to post

Reduced intake reduces electrolyte intake alongside everything else, which is the mechanism behind most of what gets attributed to the compound here.

0 likes in reply to #12 13mo

g.valckenaereTL3Regular16 Jun 2025#18

Magnesium supplementation is widely recommended in this space with very little supporting evidence for the indications it is recommended for.

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m.ilungaTL217 Jun 2025 · edited#19

Baseline measurements before a substantial change in intake give you something to compare against, and almost nobody has them.

Someone will know this better than I do and I hope they say so.

28 likes 13mo

d.szymanskiTL3Wiki editor17 Jun 2025#20

g.valckenaere, post #18: Magnesium supplementation is widely recommended in this space with very little supporting evidence for the indications it is recommended for. Go to post

The arithmetic in post #19 is right; the assumption feeding it is the part to check.

Cramping is the symptom most confidently attributed to electrolytes and has the weakest evidence linking it to them.

I checked the source rather than the summary, and they differ.

14 likes in reply to #18 13mo

lyophil_marginTL3Regular18 Jun 2025 · edited#21

Adding salt to food is the intervention most consistently reported as helping and is also the one least likely to cause harm.

That distinction has done more work for me than anything else in this category.

3 likes 13mo

m.yildizTL219 Jun 2025#22

Potassium: similar to sodium; losing weight involves some potassium loss. Bananas, sweet potatoes, and other potassium-rich foods help. Severe depletion is rare but symptomatic (weakness, palpitations).

11 likes 13mo

k.farrugiaTL3Regular20 Jun 2025#23

st.diallo, post #15: This is the answer, and the reason it is the answer is the more useful part. Go to post

Post #20 answers the question as asked. The question underneath it is different.

Sodium: losing weight involves losing some sodium. Electrolyte drinks or salty foods help maintain sodium balance. Very low sodium intake on these compounds raises orthostatic symptoms risk.

I am confident about the direction and much less about the magnitude.

24 likes in reply to #15 13mo

r.oyelaranTL220 Jun 2025#24

lyophil_margin, post #21: Adding salt to food is the intervention most consistently reported as helping and is also the one least likely to cause harm. That distinction has done more work for me than anything else in this category. Go to post

I read post #22 twice before replying, because I had assumed the opposite.

Supplementing without measuring is the default approach described here and it carries its own risks, particularly for potassium.

If that is already documented somewhere, ignore me and link it.

0 likes in reply to #21 13mo

figure_reviewTL2Member21 Jun 2025#25

Marking my place. If it changes for me I will come back and say so.

1 like 13mo

j.marchettiTL222 Jun 2025#26

Sodium is worth one more sentence than it usually gets, and the sentence is the one about how the number was arrived at.

7 likes 13mo

NorringtonTL3Regular23 Jun 2025#27

Post #24 is right about the mechanism and I think understates the practical bit.

Exercise and electrolyte losses: sweating during exercise increases sodium and potassium losses. Electrolyte replacement during or after intense exercise helps maintain balance.

Flagging that the sources on this are thinner than the confidence in the thread suggests.

17 likes in reply to #21 13mo

e.kuipersTL224 Jun 2025#28

Orthostatic symptoms: dizziness on standing after lying down can indicate dehydration or electrolyte depletion. Increasing fluids, salt, and potassium usually resolves it.

Genuinely open to being wrong about this one.

0 likes 13mo

cannula_notesTL2Member24 Jun 2025#29

Post #28 is the version of this I will quote in future. One addition.

Constipation and hydration: dehydration makes constipation worse. Increasing fluid intake is the first intervention for constipation alongside other measures.

0 likes in reply to #1 13mo

e.krastevTL225 Jun 2025#30

Where I part company with post #26, and it is a narrow parting.

Small methodological point on sodium: repeating a measurement is cheap and resolves most of what is being argued about here at no cost to anyone.

4 likes 13mo

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