The complete Test, Don't Guess series — clinical investigation, practitioner reality, and the body you are living in. All four are available on Amazon.
The Test, Don't Guess series grew out of nearly forty years of working with people — and from a single observation that has never changed: the gap between what standard investigation finds and what is actually happening is where most chronic health problems live.
The four books address that gap from four different angles. Together they form a complete clinical philosophy. Each stands alone. Metabolic Natures — Book 4 — is now Metabolic Natures, Volume 1: Your Reading, Your Plate, written to the current method.
The foundational book. Why standard testing is designed to miss functional dysfunction. What five tests — blood chemistry, GI-MAP, DUTCH Plus, Organic Acids, and food sensitivity — reveal that a standard panel cannot. How to read results to optimal rather than just normal ranges. The framework that connects findings into a protocol.
"Your tests are normal. But normal is not the same as optimal — and the distance between those two points is where most chronic health problems live."
The test results are not the hard part. Getting someone to act on them — consistently, sustainably, in the actual Tuesday morning of their life — that is the hard part. And nobody puts it in the course materials. The psychology of behaviour change, the neuroscience of recovery, the conversations that determine whether a protocol works. The human layer of the work.
"The test results are not the hard part. Getting someone to act on them — consistently, sustainably, in the actual Tuesday morning of their life — that is the hard part. And nobody puts it in the course materials."
Your body is not seven separate problems waiting for seven separate specialists. It is one interconnected system — and the fatigue, the hormonal disruption, the weight that won't shift, the gut symptoms that persist despite the perfect diet — these are not mysterious. They are the predictable downstream consequences of upstream disruptions that standard investigation doesn't look for. This book looks for them.
"Your body is not seven separate problems waiting for seven separate specialists. It is one interconnected system — and its disruptions are predictable, not mysterious, once you know where to look."
About these editions. Test, Don’t Guess, When the Rubber Hits the Road and The Seven Systems were written before my current way of grading evidence. Revised editions are in progress. Until they are out, where a book and this site differ, the site is my current position: for example on IgG food panels, urinary neurotransmitter tests, cholesterol, and supplement doses. Metabolic Natures, Volume 1 is current.
Volume 1: Your Reading, Your Plate
Why does every diet work for someone and fail someone else? People really do respond differently to the same food. A structured, testable starting point for how you eat. The evidence sets the rules it can; every plan writes down what should change before you start, so your own results can say no.
Two axes and six positions. A questionnaire gives you a starting point, not a diagnosis. Where testing shows how your body is working now, current function governs. And before you start, you write down what should change and by when, then check it. The earlier book said tests could confirm a position; they can’t, and the dated correction lists what changed.
"The question was never which diet is correct. The question was always which metabolic system it was operating on — and whether those two things were compatible."
If you have NHS or private blood results, the Initial Consultation (£145) reads every marker in your Health Status Report, alongside your history. If you have GI-MAP, DUTCH Plus or OAT results, Results & Plan (£295, £236 for returning clients) gives you a full read with a consultation, a plan and a follow-up.
The Initial Consultation → Results & Plan →The TDG Five-Test Programme is the clinical investigation the books describe — applied to you, your results, your biology.