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What is the low-carb diet? Dr David Unwin explains...

helen30 May 2019
What is the low-carb diet? Dr David Unwin explains...

Considered one of the most influential GPs in the UK, Dr David Unwin FRCGP is recognised worldwide as an expert on the topic of carbohydrates and type 2 diabetes. In 2016, he won NHS Innovator of the Year award for his work with diabetes patients and his practice has saved thousands of pounds by offering a dietary alternative to medication.

Married to Clinical Health Psychologist, Dr Jen Unwin FBPsS, the husband-wife duo have pioneered a low-carb high-fat approach in the treatment of obesity and diabetes, helping patients to improve their health and wellbeing through lifestyle change. (Read Dr Jen's blog on sugar addition here)

We therefore feel very priviledged to have Dr David talking to us about the low-carb diet, after all, you won't get more knowledgeable than him on the subject! So if you're interested read on and soak it all up!

Over to you Dr David...

The Low-carbohydrate diet for pre-diabetes and Type 2 Diabetes explained

(Also good for reducing middle aged spread and may improve liver function)

Someone with diabetes has a particular problem in metabolizing glucose, so the blood sugar levels after a sugary or carby meal stay at high levels possibly damaging the small blood vessels in the eye, kidney and other organs.

So cut back on foods either containing sugars or built up from sugars, which form their building blocks. The starches in flour, potatoes, rice, breakfast cereals and other grains are examples where glucose is concentrated by the plant for storage. When we eat these starches the process of digestion rapidly breaks them back down into glucose. This is why they are said to have a high glycaemic index (high GI)

It seems to make particular sense for those with Type 2 Diabetes not to take in high GI carbs given that we can live well off other foods such as green veg, protein like that found in eggs, meat & fish also nuts and healthy fats like olive oil or even butter. Any weight loss that comes with the diet can really help people with diabetes to avoid medication altogether and feel healthier into the bargain!

Indeed the UK NICE guidelines include the advice: Encourage low glycaemic index sources of carbohydrate in the diet. Here is an infogram to explain this:

How does insulin fit in?  How can eating these carbs make you more hungry? After digestion of carbohydrate any glucose released is rapidly absorbed into the bloodstream –the body knows that high blood sugar levels are toxic to it, so responds by producing the hormone insulin from the pancreas gland.

One of the functions of insulin is to cause your abdominal fat cells and liver to absorb the excess blood glucose to produce fat. The resultant lower blood glucose level may cause you to have hunger or ‘carb cravings’ and you return to the cookie jar to repeat the cycle, possibly getting fatter in the process.

According to many experts on low-carb diets, including Gary Taubes and the late Dr. Atkins, lower insulin levels as a result of reduced carb consumption is the main reason for the effectiveness of low-carb diets. Over 33 good scientific studies have shown the approach to work well.

They feel that, when carbs are restricted and insulin levels go down, the fat isn’t “locked” away in the fat cells anymore and becomes accessible for the body to use as alternative energy source. In this way you become a ‘fat burner’ leading to reduced need for eating.

It’s quite possible for the body to become adapted to burning fat (rather than sugar) as its main fuel over several weeks. Many on the low-carb diet notice they lose belly fat first because of this.

The low carb diet is a lifestyle choice rather than a diet for a few weeks, because of course going back to the carbs will stimulate the insulin levels and obesity again, to cause worsening diabetes.

Will a diet higher in healthy fats increase my cholesterol level? Surprisingly low carb studies often show the opposite, because much of the fat in your blood is manufactured from carbs in your liver and has not come from the diet at all. This applies particularly to triglyceride levels, also the healthy HDL Cholesterol usually rises.


This information is only part of how any particular person may decide which diet or indeed lifestyle is the best for them. If you are on prescribed medication or suffer from a significant medical condition we strongly advise you to consult your own doctor before making changes. For example improvements in lifestyle and weight loss may also significantly improve your blood pressure or diabetes control requiring a reduction in medication.


Thank you Dr David

Dr David Unwin FRCGP

RCGP National Champion for Collaborative Care and Support Planning in Obesity & Diabetes

RCGP clinical expert in diabetes

Ambassador for the All Party Parliamentary Group on Diabetes

Founder member of The Public Health Collaboration

NHS Innovator of the year 2016

Did you know Purition can help you achieve a low-carb diet and cut down on sugar in a natural way? Made with real food ingredients, each serving contains less than 4g of carbohydrates whilst being high in digestion-slowing fibre (7g). This makes for an ideal low-carb meal that will help you to avoid sugar overload and keep you feeling fuller for longer.

When managing Type 2 diabetes with food or looking to put Type 2 diabetes into remission with diet and lifestyle changes, customers report that the convenience of Purition helps (Click here for more on Purition and type 2 diabetes).

It can take a couple of days to get used to the natural taste of Purition.But stick with it, swap your usual breakfast for our nutritious shakes and you will start to feel the difference. Become your own evidence.

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