You’ve had a letter back from the surgery. Most of it looked fine. One line had a flag next to it, and you thought, I’ll ask about that at some point. Then you didn’t, and nobody rang, and life carried on.
That was me in January last year. My results came back better than they had looked since 2012. Off all my medication since February 2024. Over four and a half stone gone. And one line sitting under the reference range, which I read, noticed, and did nothing about.
Three months later that same number had halved.
No symptoms. Nobody chasing it. Including me.
The Line I Read and Did Nothing About
January 2025. HbA1c came back at 40. Thirteen months earlier that number had been 46, which is pre-diabetic, which is where I’d been parked for the best part of a decade. I’d typed “hba1c blood test results explained” into Google more times than I’d like to admit, and for once the answer was a good one.
Then one line further down the page.
Ferritin. 18.4. The reference range starts at 30.
So that’s low. Flagged low, printed in black and white, on a letter I read all the way through.
And I did nothing.
Not “I meant to and forgot about it”. I read it, thought bit low, that, and got on with my day. Because everything else on the page was the best it had looked in years. When most of a page is moving the right way and one line isn’t, you don’t hear an alarm. You hear background noise.
Here’s the belief underneath it, and I’d carried it for thirteen years without ever once saying it out loud. If a result matters, somebody chases it. The surgery rings. A letter turns up. Something happens.
That isn’t a daft assumption, by the way. It’s exactly what the NHS had done for me, repeatedly, across a decade of blood tests.
Nobody rang. And I was that pleased with the rest of the page that I didn’t ring either.
Two Numbers, Three Months Apart
December 2023. Ferritin 141. Middle of the range, no notes, nothing to look at. That’s the last time that number was anywhere near normal.
January 2025. 18.4.
April 2025. 8.90.
The range starts at 30, so 8.90 is roughly seventy per cent below the bottom of normal. And from January to April, over about three months, it dropped by fifty-two per cent.
Now put that next to the rest of the April letter. HbA1c 37, the lowest reading in records going back to 2012s. CRP at 1.0, which is about as quiet as inflammation gets, and I only knew that because I’d gone looking myself at half ten at night. “What are inflammation markers in a blood test”, that sort of search. Weight around thirteen stone. Over a year off everything.
Not all of it was tidy, mind. Cholesterol was still 7.11. Triglycerides had gone up, not down. So it wasn’t a clean sweep and I’m not going to pretend it was.
But there was no line on that page that read this one is falling off a cliff. Every result gets its own tick or its own flag, on its own, in its own row. Nothing on an NHS printout draws you an arrow between January and April and says look at the slope.
And that’s not somebody being careless. A blood test result is a snapshot, and the printout is built to report a moment. The line between two moments isn’t anybody’s job. Not in a ten minute appointment, and not on a page that gets filed in a drawer.
Which brings me to the bit I got wrong, so I’ll say it plainly.
I’d been comparing my numbers to the reference range for years. I’d sat there checking the “fasting glucose blood test normal range” against my own results like it was a school report. In range, good. Out of range, look into it.
What I never did was compare a number to itself.
18.4 is a low number. 18.4 heading to 8.9 is a completely different thing. Same marker, same person, three months apart, and I only ever looked at each one on its own.
I Blamed the Fasting, and I Was Wrong
Something did happen, and I want to be fair to my GP here. In late March a set of tests was requested. Repeat bloods, and a coeliac screen alongside them, which is one of the things you look for when iron is disappearing and nobody knows where it’s going.
That screen came back on the sixteenth of April. Negative. Reviewed by a GP, marked no further action, patient informed.
And I read “negative” and heard “sorted”.
One possible cause got ruled out properly. The number itself carried on sitting on the floor. But the last thing written on the file said no further action, and it’s remarkable how quickly three words like that will close a thing down in your head.
When I did finally sit up and pay attention, I blamed the wrong thing entirely.
I blamed the fasting. Course I did. It was the obvious answer and it was sat right there. Long fasts, eating in a window, a lot less red meat than I used to put away. I spent a fair while wondering whether the thing that had taken me off all my medication had quietly cost me something else on the way.
Here’s what I should have known, and it isn’t my opinion, it’s NHS guidance. When iron stores come back low, the job is to find out what’s causing it. Not just top it up and move on.
And the guidance is fairly blunt about diet, as it turns out. For a grown man eating almost no iron at all, you’d be looking at years before it showed up in his stores. Years. Not a few months of a shorter eating window.
What it points at instead is blood loss. For men, and for women past the menopause, the commonest reason is bleeding you haven’t noticed. For younger women it’s usually periods. Either way the instruction is the same. Find out which.
Which, as it turned out, was me.
Bleeding piles. Chronic, low level blood loss, going on for months, and the sort of thing you can have without ever really registering it. My GP found it by investigating properly rather than guessing, and it was dealt with in November of last year. Bleeding stopped. My GP put me on iron afterwards to build the stores back up.
Nothing whatsoever to do with anything I was eating.
And I’ll say this clearly, because it matters. That’s my answer. It isn’t yours. For some people it will be the eating pattern, and that is exactly why you get it looked at instead of guessing in either direction.
Why You Can Feel Perfectly Fine at 18
So that’s the illness sorted. Cause found, cause treated, iron on the way back up, file closed, November 2025.
Here’s the bit that actually bothers me, and it happened six months after all that.
May this year. I’m at my desk putting NHS results going back to 2012s into one file, so that for once they’d all be in the same place instead of scattered across a decade of envelopes.
Ferritin went in. January 2025, 18.4. April 2025, 8.9.
Two cells. Next to each other. First time.
And I sat back in the chair. Because the piles were fixed. That whole thing was months behind me. And I was sat there looking at a drop I had never once seen as a drop. Thirteen months, two letters, one drawer, four feet from where I do all my tracking, and nobody had ever put those two numbers on the same line. Not the surgery. Not me.
The illness got sorted. The blind spot didn’t.
So how does a number fall that far, for that long, without anybody noticing? Including the bloke obsessed with tracking?
Because I felt fine. That’s it. That’s the whole of it.
Imagine you had to wait for your engine to seize before you found out the car was low on oil. You’d never run a car like that. You’d check it, you’d watch the light, you’d listen for the noise. But that’s more or less how most of us treat our own bodies, and I include myself in that. The seizing isn’t the problem. The seizing is the late notification.
Iron stores work the same way. You’ve got a reserve. That reserve can run right down while you carry on feeling perfectly normal, because the thing that makes you feel ill is what happens after the reserve has gone.
Feeling fine at 18 tells you nothing about what’s coming at 8.9.
I can’t tell you what your numbers mean. This is one bloke’s panel and records going back to 2012s, not a trial. But I can tell you the mistake, because I made it twice in the same story. First I read a result and didn’t look at where it was heading. Then I decided I already knew why, and I was wrong about that as well.
A number on the floor is a question. It isn’t a diagnosis, and it certainly isn’t a verdict on whatever you happen to be doing at the time.
What I’d Read Differently Now
If I were starting the tracking again tomorrow, I’d change one thing. I’d stop reading results as a pass or a fail against the range, and start reading them as a direction. A low number that’s been low for years is one situation. A low number that’s got lower is a different situation entirely, and you cannot see the difference from a single letter. If I’d repeated that ferritin in February instead of waiting for the next routine panel, I’d have seen the slope with two months still on the clock.
That isn’t more discipline, by the way, and it isn’t more testing. It’s the same letter, read a different way. Which is about as low effort as a change gets.
If I were sat looking at my own data now and I found a marker that got flagged once and nobody has mentioned since, never repeated, that’s the one I’d be looking at first. Especially if something else had changed around the same time. New eating pattern, a lot of weight off, a medication stopped.
But I wouldn’t do what I did and decide I already knew why. If it were me, I’d want to ask my GP to find out what’s causing it. Not a supplement. Not a theory. An investigation.
And if none of this has ever been tested, that’s the version of me at forty I’d want to say something to.
Feeling fine is not evidence. It’s a lovely thing and I hope it lasts you decades, but it is not the same as the numbers being fine, and my own records say so in black and white. If your energy has been slightly off for no reason you can name, not ill, not stressed, just not right, that’s not a diagnosis and it isn’t something to panic about. It’s a decent reason to be curious, and to find out what your baseline actually is while everything still feels normal.
Because a baseline is only any use if you took it before you needed it.
So here’s the one I’d leave you with. If there’s a result of yours sitting in a drawer somewhere that got flagged once and never got repeated, do you actually know which way it was heading?
I didn’t. For thirteen months. Four feet from my desk.
🎯 Key Takeaways
- A single reading tells you less than the direction: 18.4 and 8.9 are the same marker three months apart, and only one of those numbers is frightening
- Nobody owns the trend line: an NHS printout reports a moment, and the slope between two moments isn’t built into the page
- Feeling fine is not the same as the numbers being fine: a reserve can run right down before anything starts to hurt
- A low result is a question, not a cause: in my case it was chronic blood loss, and it had nothing to do with how I was eating
- Assuming you know why is the second mistake: I made it, and it cost me months on top of the ones I’d already lost
Ready to Start Your Own Rhythm Reset?
If reading this has made you want to get your own numbers moving before you’re reading them in a panic, the 14-Day Rhythm Reset Guide is where I’d start. It covers the eating window, what goes in it, and how to build a rhythm you can actually hold long enough for the next set of bloods to say something useful.
👉 Get the 14-Day Rhythm Reset Guide (free)
💪 Want ongoing support? Join Rhythm Club for £30/month (includes FREE app access, community, and weekly accountability calls)
⚠️ Important: This is educational content based on evidence and personal experience. It is not medical advice. Speak to your GP before making changes to your fasting pattern, diet, or medication.
Questions? Email hello@waymorethanweightloss.com
© 2025 Way More Than Weight Loss. All Rights Reserved.
