EXPERT TALK

Dr David Unwin

NHS General Practitioner. Low Carb Pioneer. Named Among the Top 10 Most Influential Doctors in the UK, 2018.

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Who he is

Dr David Unwin has been a GP just north of Liverpool since 1986 and is still there. In 2018 he was named among the top ten most influential doctors in the United Kingdom. He developed type 2 diabetes himself from a long-standing biscuit habit, reversed it through a lower carbohydrate approach, and has since achieved drug-free type 2 diabetes remission in over 157 patients at his NHS practice.

He co-founded the Public Health Collaboration, a UK charity, with Dr Rangan Chatterjee, which has now produced sugar equivalent infographics translated into 35 languages and distributed freely around the world.

His wife Jen Unwin is a clinical health psychologist who co-developed their patient programme and has published extensively on ultra-processed food addiction. Her book Fork in the Road, in which all profits go to a food addiction charity, simplifies the behaviour change process for people who find they cannot moderate certain foods. Together they run Monday evening sessions at their practice, free of charge, for patients who want to try a lower carbohydrate approach.

Why his work matters for this site

This site documents how everyday chemical exposures disrupt the endocrine system and affect hormonal health across a lifetime. Dr Unwin's work belongs here because the connection between ultra-processed food and hormonal disruption is not just metaphorical. It is chemical and direct.

A 2024 study in Diabetologia confirmed that packaging contaminants in ultra-processed foods, specifically phthalates, BPA and PFAS, are linked to endocrine disruption, inflammation and insulin resistance. These are the same chemicals documented elsewhere on this site in the context of fertility and reproductive health. They do not stay in the packaging. They migrate into the food.

Insulin resistance is itself a form of hormonal disruption. When the body can no longer respond normally to insulin, it affects sex hormone production, cortisol regulation, thyroid function and the hormonal balance that governs energy, mood and weight. The evidence is particularly significant for women in perimenopause, where insulin resistance tends to accelerate and where the hormonal changes of this transition compound the metabolic effects of a high carbohydrate diet.

Key findings and insights

The sugar in food that nobody is telling you about

Dr Unwin's most widely shared contribution is his teaspoon of sugar equivalent system, which converts the glycemic load of common foods into units that mean something to a patient sitting across a desk.

The key insight is that starch is sugar. Glucose molecules holding hands. Digestion breaks those bonds and releases the glucose into the bloodstream just as effectively as table sugar would. The food does not taste sweet. But the body responds identically.

A bowl of plain cornflakes contains the blood glucose equivalent of eight teaspoons of sugar. A baked potato is nine. 150g of boiled rice is ten. A ripe banana is six. A standard bottle of barbecue sauce contains the equivalent of 30 teaspoons of sugar. White chocolate is approximately 70 to 80 percent white sugar by composition.

The human body maintains the equivalent of roughly one teaspoon of sugar in its entire blood volume at any one time. The scale of the imbalance between that narrow normal range and what a standard Western breakfast delivers is the thing most people find hardest to absorb.

The moment that changed everything

In 2012, a patient he had known for over ten years came into his surgery after he had written to express concern that she had stopped taking her metformin. She came in furious. She said she had learned online what he had never told her in 25 years of treatment: that bread is sugar, that rice is sugar, that breakfast cereals are sugar. She had cut those foods. Her blood sugar was completely normal without any medication.

It was the first case of drug-free type 2 diabetes remission he had seen in a quarter century of practice. He spent the next decade documenting 156 more.

Published research

Where to find him

Dr Unwin is active on X at @lowcarbGP, where he regularly posts his sugar equivalent infographics and clinical findings. His infographics are not copyrighted and are freely available for download and redistribution in 35 languages through the Public Health Collaboration website.