The Blog

A full blood panel can be reported as entirely normal while the patient is experiencing progressive anaemia, B12 deficiency, declining cognition, and drug-induced malabsorption simultaneously. The problem is not the test — it’s what we’re looking for in it.

Standard medicine tests for disease. Functional medicine tests for dysfunction — the state that precedes disease by years or decades. Here’s what the tests conventional medicine never orders actually reveal.

Your results are compared to the average of the local population. In a population where metabolic disease is epidemic, “normal” includes a lot of people who aren’t well.

Normal tests don’t mean nothing is wrong. They mean nothing was found — with the tools that were used. The standard panel looks at 8–12 markers. We look at 65+.

Your GP report says “within range.” The patterns hiding between the numbers tell a different story — insulin resistance, iron metabolism, thyroid conversion, and inflammation.

The wrong arm. A non-fasted sample for markers that require fasting. The biggest failures in blood testing happen before the blood reaches the lab.

TSH is one marker. One. It tells you what the pituitary is asking the thyroid to do — not what the thyroid is producing, not whether T4 is converting to T3, and not whether antibodies are destroying the gland.

Susanna Holt’s 1995 study measured how full 38 foods kept people per calorie. Boiled potatoes scored 323%. Croissants scored 47%. The four mechanisms that predict satiety, why ultra-processed food bypasses all of them, and why GLP-1 drugs are doing pharmacologically what high-satiety meals have always done for free.

Meal timing, insulin partitioning, protein thermogenesis, testosterone:cortisol balance, and satiety science were all established by the mid-1990s and being taught to clients as free practical guides. Thirty years later they are being sold as revolutionary discoveries. The obesity epidemic is not a knowledge gap. The framework was right. The tools are just better now.

Whey raises insulin 90% more than bread does — while raising blood sugar 57% less. This finding has been misread to mean protein is dangerous. It actually explains GLP-1 mechanism, why pre-meal protein improves blood sugar control, and how the satiety science behind Ozempic has been available through food for thirty years.

Standard testing catches prediabetes at the end of a ten-year metabolic process. Fasting insulin and HOMA-IR catch it at the beginning — when reversal requires only moderate lifestyle intervention rather than pharmaceutical management. The timeline, the markers that see it coming, and the interventions with evidence for genuine reversal.

Your fasting glucose is normal. Your fasting insulin isn’t tested. HOMA-IR catches insulin resistance years before glucose rises — and it’s not on the standard panel.

Your haemoglobin is fine, so you’re not anaemic. But your ferritin is 15, your hair is falling out, and you can’t get up the stairs. Iron deficiency without anaemia is one of the most under-diagnosed patterns in primary care.

Ferritin at 15 is within range. But optimal is 70–100. The difference between “not anaemic” and “functioning well” is the gap between conventional and functional ranges.

Going to the gym doesn’t undo eight hours of sitting. Six mechanisms by which prolonged sitting disrupts gut function independently of exercise — colonic transit, vagal tone, pelvic floor, lymphatic flow, blood sugar, and breathing mechanics.

Cutting out gluten. Dairy-free. Probiotics. Digestive enzymes. Still bloated. The reason those approaches haven’t worked is almost always the same: the advice was based on the symptom, not the cause. Here are the six biological drivers of chronic bloating — and why testing is the only way to know which one is yours.

Position. Breathing. Psychology. Timing. The mechanics of a bowel movement are more fixable than most people realise — and almost nobody talks about them honestly. If you can’t go without your phone, your nervous system is telling you something.

Fatigue that doesn’t respond to sleep or rest often has a cellular origin. The OAT maps mitochondrial function, neurotransmitter production, B-vitamin status, and gut overgrowth from a single urine sample — and explains why fatigue that “nothing explains” often has a very specific biochemical cause.

The GI-MAP tells you what’s living in your gut. The OAT tells you what those organisms are producing and what that’s doing to your body. Run them together and they explain each other in ways that change the entire clinical picture.

Small intestinal bacterial overgrowth drives a significant proportion of IBS diagnoses and remains undetected in most of them. But SIBO has multiple upstream causes — low stomach acid, thyroid, bile, motility, antibiotics — and treating the overgrowth without identifying why it happened is why it keeps coming back.

Glyphosate is detectable in the urine of the majority of people tested. It doesn’t cause obvious symptoms. What it does instead is selectively suppress the gut bacteria that keep dysbiosis in check — while leaving the problematic ones largely unaffected.

Spinach. Almonds. Dark chocolate. All on the functional nutrition approved list. All very high in oxalates. When the gut bacteria that degrade them are depleted, these compounds accumulate in tissue and produce pain, fatigue, and joint problems nobody traces back to breakfast.

Why does exercise make you hungrier during weight loss — and what does that mean for your programme design? The exercise-appetite compensation effect, ghrelin rebound, why HIIT outperforms steady-state cardio for satiety, and the honest truth about swimming and weight loss.

My dog Dexter goes to the toilet at the same time every morning without fail. Most of my clients can’t say that. There’s a clinical reason for both — and it’s more fixable than you think.

GLP-1 is a hormone your gut already makes. Here’s what impairs it, what the Akkermansia research actually shows, why food texture matters more than calories, and how to optimise it before pharmaceutical intervention becomes a conversation.

Liver support, gut repair, and blood sugar stabilisation — each recipe built around the clinical mechanisms that make it work. Not health food. Not punishment. Food that does something specific.

Quantitative PCR technology measuring bacteria, parasites, fungi, viruses, and inflammatory markers. What standard stool culture can’t tell you — and why it matters for skin, joints, brain fog, and immunity.

Protease, lipase, amylase, lactase, and alpha-galactosidase each address a completely different digestive failure. The GI-MAP elastase marker is the objective test for pancreatic output. The symptom-to-enzyme table maps which enzyme is indicated for which specific pattern. And the cephalic phase — slow eating, chewing — is the most underutilised digestive “supplement” available.

The GI-MAP zonulin, secretory IgA, and calprotectin markers establish the specific barrier picture. L-glutamine, zinc carnosine, collagen, butyrate, and DGL are the repair nutrients. But the 5R sequence — remove, replace, reinoculate, repair, rebalance — determines whether the repair holds. Applying repair nutrients without completing steps 1–3 first is painting over damp.

Low stomach acid is behind more gut problems than almost any other single factor — and it is almost never tested. The mechanism connects directly to SIBO recurrence, food sensitivity, iron malabsorption, H. pylori, and the downstream enzyme cascade. Betaine HCl, apple cider vinegar, and what the GI-MAP reveals about the upstream cause.

Zonulin, secretory IgA, anti-gliadin antibodies, calprotectin, pancreatic elastase. The markers that turn a stool test from a pathogen hunt into a functional assessment.

The clinical case for dairy as bioavailable calcium, the forgotten power of organ meats and cod liver oil, and why soaking your oats isn’t just a TikTok trend.

Soluble, insoluble, resistant starch, prebiotic fibres. What they do, how much you need, and why the standard Western diet is catastrophically low.

Type I, II, III. Hydrolysed peptides, bone broth, glycine. What works, what’s marketing, and how it fits into a gut repair protocol.

Eczema that no dermatologist could resolve. Dysbiotic flora, elevated zonulin, compromised secretory IgA. When the gut healed, the skin cleared.

The most stressed person in the room is often the one who isn’t in crisis. Stress is not a fixed quantity — it’s the relationship between load and capacity, and every variable in that equation is individual.

Loneliness reduces gut microbiome diversity, elevates cortisol, shifts immune gene expression toward inflammation, and is independently associated with significantly increased mortality risk. It is not a feeling. It is a physiological state.

Physical and emotional trauma alter the biological terrain in measurable ways — the calcium shell, the cell danger response, vagal tone and cervical trauma, pyroluria and zinc-copper imbalance. And why disconnection from the body is one of the most consequential clinical findings in practice.

Cortisol does not merely respond to stress — it reorganises the entire hormonal hierarchy around survival. The four cortisol patterns visible only on the DUTCH Plus, pregnenolone steal, and why you cannot fix sex hormones, thyroid, or immune function without understanding what cortisol is doing first.

Why TSH alone misses most thyroid dysfunction. The three oestrogen metabolism pathways that determine cancer risk. Why testosterone is downstream of stress, sleep, and insulin. And the hormone replacement question — addressed directly, including the Depo-Provera meningioma precedent.

Your cells are making light right now. Your dog just communicated something to you without language. Slime mould solves mazes without a brain. And somewhere in your body, a signal is being sent that you are not listening to. The biology of health from its first principles — from biophotons through body awareness to the cacophony of signals that determines whether you eat well or not.

Why does one person in a family get sick while another doesn’t? Why do GPs examine throats for thirty years without disproportionate illness? Cohen’s cold studies, Sapolsky on social stress, immune tolerance, and why two people in the same physical environment are not living in the same biological one.

October 2021. Pulse ox under 96. Nebuliser twice a day. Missing my best friend’s wedding. I had written about stress suppressing immunity sixteen months earlier. The psychoneuroimmunology of what actually happened — and why knowing the mechanism does not protect you from the mechanism.

Not just relaxation. Parasympathetic activation, measurable cortisol reduction, vagal tone improvement, and lymphatic support — with the evidence behind each. Where massage fits in a TDG-led protocol, what it cannot do, and recommended practitioners in Glasgow and Edinburgh.

The average woman applies 168 chemicals to her skin before leaving the house. Here’s the enzyme competition mechanism, the biomonitoring data, and why it matters clinically when you’re working on oestrogen clearance.

Nature immersion, vagal tone, grounding, art, and the measurable parasympathetic benefits of getting away from your phone, your routine, and your postcode. Plus four recommended experiences.

Two women with identical serum oestrogen levels can have completely different metabolite profiles and clinical needs. The DUTCH Plus shows oestrogen pathways, progesterone metabolites, and how the cortisol awakening response is interacting with every other hormone during the perimenopausal transition.

You know what to eat. The reason you don’t always do it is not willpower. It is the childhood conditioning, family food rules, neurochemical reality of cravings, social eating architecture, and metabolic disruption that shapes every food decision — most of which was built before you were old enough to question it.

You already know what you should be doing. The information was never the problem. The intention-behaviour gap is real and measurable. The stages of change model explains why most advice lands at the wrong stage. The biology of HPA dysregulation, blood glucose, and sleep deprivation explains why the neurobiology works against you. And data changes the motivational context in ways that advice alone cannot.

The Sunday-to-Monday cortisol shift is real and measurable. What your dread is telling you about your HPA axis, your autonomic nervous system, and your relationship with your work.

Under chronic stress, pregnenolone is shunted toward cortisol production at the expense of sex hormones. This is measurable on a DUTCH test — and it explains a lot.

Because weight loss isn’t a calorie equation. It’s a hormonal equation — insulin, cortisol, thyroid, sex hormones, and gut function all determine whether your body releases or holds fat.

In 2016 a peer-reviewed paper argued that bread affects mental health through two independent mechanisms: gut permeability and opioid-like exorphins. A decade on, the evidence is stronger and the psychiatric system still isn’t listening.

MTHFR variants impair the methylation cycle that produces every major neurotransmitter. Depression, anxiety, OCD, ADHD, bipolar disorder — all have documented associations with impaired folate metabolism. And we are adding synthetic folic acid to every loaf of bread.

From the end of 2026, synthetic folic acid will be added to all non-wholemeal wheat flour in the UK without your consent. For people with MTHFR variants, this is not a public health win. It is a clinical risk — and it is testable.

Medicine was built to recognise and treat the absence of health — not to cultivate its presence. The sliding scale between acutely ill and fully optimised is where most people actually live. And it is the place the system is least equipped to serve.

Your client has never once finished a set early. But somehow, at exactly 30 seconds, they collapse. To the nanosecond. This is not fatigue — it is self-preservation calibrated to the agreed duration of the set. Why exercise science designed for athletes does not map onto the deconditioned client, and what to do instead.

An enlarged liver pulls on the diaphragm. The diaphragm alters breathing. Altered breathing changes posture. Posture loads the right hip flexor. The hip flexor attaches to the lumbar spine. Your back hurts. The clinical cascade nobody joins up — fascia, visceral anatomy, the ECM, and Thomas Myers.

Inefficiency is a win — until it isn’t. Efficiency is a win — until it isn’t. The four-stage skill acquisition journey most coaches never explain, the phasic vs postural muscle distinction, and why the same walk every day for ten years is not ten years of benefit.

Fox walking, nasal breathing, the core exercise most people have backwards, the overhead swing as a nervous system reset, and why the pace at which you can breathe through your nose is the therapeutic pace. A complete movement practice built from 37 years of coaching.

In the 1990s I clipped a research-grade accelerometer to my belt. The four Apple Health mobility metrics most people scroll past — walking asymmetry, double support time, walking speed, step length — and what they reveal about biological age and functional capacity.

Eating out is not the enemy of a functional medicine programme. Done well — the right restaurant, slow meal, good company — it is itself a clinical intervention. The practical ordering guide, the Italian template, and where I actually send clients in Edinburgh.

Seven evidence-based practices with solid human data behind them — and an honest conversation about why they still might not be enough. Post-meal walks, morning light, resistance training, vitamin D with VDR caveats, binders. Done before supplements.

Eight clinical forms, three contraindications, and one question you need to answer before you start. The honest pros, genuine cons, form-by-form breakdown, and the three human studies that back it up.

Not a lecture. Not permission. Liver enzymes, gut permeability, candida, blood sugar, sulfites, genetics, and why “moderate” means something different for every body.

PPIs, statins, metformin, the pill. Every one depletes specific nutrients. The pharmacology textbooks document it. Your prescriber didn’t mention it.

Twelve common medication categories and their documented nutrient interactions. CoQ10, B12, magnesium, zinc, folate — the depletions are predictable, dose-dependent, and rarely discussed.

The practical, non-dramatic changes that move the needle most — sleep timing, meal composition, hydration, movement snacks, and the unsexy habits that high performers actually do.

Steps, calories burned, miles run — none of them measure movement quality. What 37 years of coaching has taught me about the difference between exercise and functional movement.

The NHS waiting list is years long. Functional testing can identify contributing factors — blood sugar instability, nutrient deficiencies, gut-brain axis dysfunction — while you wait.

One in five buildings has significant water damage. Mycotoxins produced by indoor mould are increasingly recognised as a driver of treatment-resistant fatigue, brain fog, and multi-system symptoms. Why HLA-DR genetics explain why not everyone is affected, how the OAT and GI-MAP reveal the metabolic consequences, and why exposure removal has to come before any other intervention.

Glutathione is the body’s primary antioxidant and the molecule Phase Two liver detoxification depends on most. The OAT pyroglutamic acid marker is the most sensitive functional indicator of its depletion. Understanding NAC, GlyNAC, liposomal delivery, and why identifying the cause of depletion matters as much as the supplementation approach.

Standard blood metal testing misses chronic toxic burden because metals accumulate in tissue, not serum. The OAT as the first functional signal, hair tissue mineral analysis and its underappreciated mineral displacement patterns, when provoked urine testing is warranted, and why HTMA is sometimes the most clinically appropriate starting point.

Phase I and Phase II liver detox, why the sequence matters, bile insufficiency and gallbladder function, beta-glucuronidase and oestrogen recirculation, TUDCA, and the bitter foods reflex that modern diets have eliminated entirely.

NAFLD affects one in three adults and most don’t know it. It’s a metabolic disease, not primarily a liver disease. The bidirectional feedback loop, fructose’s specific hepatotoxicity, the gut-liver axis, and the blood markers that reveal it years before enzymes flag.

Calcium, magnesium, vitamin D, and PTH in a four-way regulatory loop the kidneys sit at the centre of. Acid-base balance, uric acid, oxalates in renal tissue, and the blood markers that show decline years before creatinine moves.

Moves more fluid than the cardiovascular system but has no pump. Movement is the pump. Skipping, rebounding, Power Plate, diaphragmatic breathing, contrast hydrotherapy — and why the glymphatic brain clearance system requires sleep to function.

Not all probiotics are the same. Lactobacillus rhamnosus GG, Saccharomyces boulardii, Bifidobacterium longum, Akkermansia muciniphila, and spore-based Bacillus species each have distinct evidence bases and clinical niches. The GI-MAP tells you which strains are depleted. And SIBO is the condition where standard probiotics consistently make things worse.

Different fibres feed different bacteria. Resistant starch feeds F. prausnitzii. Pectin feeds Akkermansia. Inulin feeds Bifidobacterium. The 30-plant principle works because diversity of substrate selects for diversity of species. And why prebiotic foods cause symptoms in SIBO — and what to do about it.

Urolithins, equol, IPA, secondary bile acids, and GABA from bacterial metabolism are the mechanisms behind much of what was previously attributed to the bacteria themselves. The Sonnenburg fermented food study. Six fermented foods and what makes each one clinically distinct. Why SIBO and histamine intolerance make fermented foods temporarily contraindicated.

Butyrate fuels the colonocytes that maintain the gut’s anaerobic environment. When it falls, the environment fails and dysbiosis follows. The GI-MAP producer species, prebiotic substrates, when to supplement, and the brain connection.

I had more than two decades of clinical practice before I did the FDN training. I was not easy to impress. Here’s what it taught me that nothing else had — and why I still use the framework as the spine of everything I do.

My grandparents ran a restaurant in Ayr — glazed rooftop dining room overlooking the Isle of Arran, long before alfresco dining in Scotland was a thing. The post office next door was where my parents met. And the way my grandparents lived was, I now understand, one of the most evidence-backed approaches to long-term health that exists.

The honest story behind Test, Don’t Guess — 37 years in health and fitness, the FDN training that changed everything, and why writing 300,000 words felt like the only way to say what needed saying.

Functional Diagnostic Nutrition — Reed Davis’s systematic approach to identifying healing opportunities through lab testing. What it is, how I use it, and why it changed my practice.

Before PubMed, before podcasts, before the algorithm — there were newsletters, phone orders, and photocopied papers. Peak Performance, MM2K, the 2001 Edinburgh movement dysfunction conference, Crayhon Research Nutrient Expo 2005. The origin story of the clinical thinking behind Detective Health.

Treating all breast cancers identically because they’re all breast cancer is a category error. So is giving everyone the same dietary advice because they’re all human beings. The principle of biochemical individuality — what it means clinically, why it matters, and why testing before guessing is the only approach that respects individual biology.