Introduction to low-carb for beginners.

Learning that you have diabetes usually comes as a bit of a shock followed by confusion from often conflicting advice.  But don’t panic, it can be managed.  It does require a bit of a lifestyle change in terms of diet and discipline, but we can and will help you with that. We were all in the same boat once!

Introduction, and Why Low-Carb?

This page has been provided for those who are new to the forum or to the concept of low-carbing as a primary tool for managing diabetes.  Although it is aimed principally at Type 2 diabetics, Type 1s and others can also benefit significantly.  'Managing diabetes' means different things to different people, but ultimately the aim for T2s should be to get your blood sugar numbers into the same area as non-diabetics.  This means an HbA1c level of less than 42 mmol/mol (6.0% in the old measurement system).  (48 mmol/mol or 6.5% and above is regarded as diabetic, 42-47 mmol/mol as prediabetic).  For T1s the aim should be the lowest practicable levels concomitant with good control and avoidance of hypos in accordance with their consultant's guidance and personal life choices.

So the main priority is to get blood sugars under control.  This is essential to minimise the risk of developing unpleasant complications (including amputations, kidney failure and blindness) if the condition is left unattended and sustained high blood sugar levels are allowed to prevail.  

The chief symptom of diabetes is an elevated blood glucose level. Whilst some medications can help Type 2 diabetics to reduce blood glucose, far more significant a factor is a reduction of those foods in the diet which raise the levels in the first place. This is not just obvious sugars in sweets, chocolate, cakes, biscuits, breakfast cereals and so on but most carbohydrates as well. 

Carbohydrates metabolise quickly to sugar in the system (some take a little longer than others) and so for diabetics they act basically as if they were sugar.  So you need to cut out starchy carbs as much as possible, including bread, potatoes, pasta and rice - 'wholemeal' or so-called 'healthy' carbs included.  This may be contrary to medical profession guidance you have received to eat carbs with every meal – unfortunately this is fundamentally flawed advice rejected by most well-controlled T2s on here.

Low-carbing can therefore result in medications (including the amount of insulin required for T1s) being reduced.  Always consult with healthcare professionals on this.  In some cases (Type 2 diabetics only) medications can be avoided or eliminated altogether.  (It is a mistake to imagine that drugs alone will enable you to manage your diabetes successfully, so don't become complacent if you are on medication – it is assumed that for most people minimisation or elimination of medication is in itself a major objective). 

What does Low-Carb mean?

A low carb diet is not necessarily low in all carbohydrate foods, simply those which disrupt blood glucose and insulin levels. Generally, the diet includes the healthy natural and unprocessed foods similar to those eaten in populations where diabetes and heart disease are rarely found. 

So you can eat/drink:

Meat, fish, eggs, butter, cheese, plain Greek yoghurt and cream
Vegetarian protein such as tofu and TVP
Above-ground green vegetables, tomatoes, avocados, nuts as a good snack
Berry fruits in moderation (blueberries, raspberries, blackberries, strawberries)
Occasional small amounts of dark chocolate (85% cocoa or more)
Tea, coffee (try with cream instead of milk)
Plenty of water
Red wine, dry white wine, champagne, spirits in sensible amounts

And you should avoid:

Sugar - soft drinks, sweets, juice, sports drinks, chocolate, cakes, buns, pastries, ice cream, breakfast cereals. Preferably avoid sweeteners as well.
Starch - bread, pasta, rice, potatoes, chips, crisps, porridge, muesli, foods containing processed flour and so on. 'Wholegrain products' are just less bad. Moderate amounts of root vegetables (carrots, parsnips) may be OK (unless you’re eating extremely low carb).
Margarine - industrially imitated butter with unnaturally high content of Omega-6 fat. Has no health benefits, tastes bad. Statistically linked to asthma, allergies and other inflammatory diseases.
Fruit, especially tropical fruits which contain lots of sugar. Eat once in a while at most. Treat tropical fruit as a natural form of sweets.  The impact of apples and pears varies from person to person.
Beer - liquid bread.  Full of rapidly absorbed carbs.
Sweet white wine, cocktails with sugary mixers.

In broad terms, carbohydrates have a large impact on blood glucose levels, protein much less, and fats have little if any effect.

An effective low carb diet (or perhaps we should refer to it as a 'lifestyle') is one which allows a person to maintain, most of the time, a healthy blood glucose level. The amount of carbs it contains will vary between individuals, depending mainly on personal choice, pancreatic function and insulin resistance.  A possible range might be: 

Low carb (ketogenic) 0-50g carbohydrate per day 
Typical low carb 50-90g
Liberal low carb 90-130g
Moderate carb 130-170g
High carb 170g and more

For low carb foods aim for those that have less than 10g total carbohydrate (excluding fibre) per 100g, less than 5g if you can. Ignore the ‘of which sugar’ bit, that’s irrelevant to us. You will become an avid reader of food labels!  (And the MyFitnessPal app can scan them).  Also avoid low fat versions of food items – these often contain added sugar.

Some prefer to keep eating some carbs, because they want to and/or they can tolerate more; and some are less able to eat higher levels of fat. 

What about LCHF?

LCHF (Low carb high fat) is a variant of low-carbing which many diabetics successfully adopt.  When you reduce carbohydrates, you also reduce the calories that come with them.  To make up these calories you can replace them with a higher proportion of fats, such as those found in fatty meat, butter, cheese and cream.  LCHF is advocated by a Swedish dietican, Dr Andreas Eenfeldt, see www.dietdoctor.com/lchf

Testing

In order to learn what foods you can and cannot tolerate it is strongly recommended that you have a test meter (not usually prescribed for T2s).  With this you can measure your blood glucose levels before and after meals and see what ‘spikes’ you.  Again this may be contrary to professional advice you might receive which often regards testing as pointless.  But how else are you supposed to learn?  Many on here use the SD Codefree system (from Amazon etc or direct from the supplier Home Health UK) because the strips are the most cost-effective.

What might happen when you start to Low-carb?

The following does not happen to all who start a low carb eating regime, but some may experience one or more of these stages.

Days 1 to 3 - carb withdrawal and hunger. Eat lots of fibre and lots of fat.  Fat and fibre together produce a high degree of satiety.  Add flax seeds, as they are high in both fibre and healthy omega-3 fatty acids.  Salads with protein (tuna, chicken, etc.) and lots of olive oil dressing is another good bet.

Don’t go hungry! This isn’t like other diets where you can expect to go for long periods being hungry.  Eat every 3 hours if you want to, snack on low carb foods (such as cheese or nuts) as you want until the hunger goes.

Days 3 to 5 - the wall.  People often lose a lot of salt with the fluid in the first few days, and you have cut out the supply from junk food, so add some salt and/or a cup of hot water with a stock cube several times per day.  

Days 5 -14 - reward time. By the end of the first week you should start to reap the rewards of low-carb eating. This is the stage where many people begin to experience increased energy, better mental concentration, better sleep patterns, less compulsive eating, and few or no carb cravings. Some experience it as a “fog lifting” that they didn’t even know was there. 

Why doesn’t the NHS recommend Low-carb diets?

The NHS are obliged to advise on the basis of NICE guidelines.  These guidelines in turn are still based on the increasingly discredited view that dietary fat causes heart disease and dietary protein causes kidney damage, so without carbs there’d be nothing left to eat. Subsequent research has revealed that neither of these hypotheses is correct and that the finger of suspicion ought to be pointed at glucose, but changes to established mindsets are very slow to happen.  Nevertheless, there has been much recent positive publicity regarding low-carbing and the negative aspects of low fat regimes and the role of sugar.

Many diabetics have discovered for themselves the benefits of low-carbing, by the simple empirical process of testing their own blood sugars to determine what foods they can tolerate and what they can't (or for T1s which foods require the minimum of insulin dosage).

The figures below show the impacts of the NICE guidance on HbA1c levels of registered diabetics.

Results for England. The National Diabetes Audit 2010-2011

Percentage of registered Type 1 patients in England

HbA1c >= 6.5% (48 mmol/mol) = 92.6%
HbA1c > 7.5% (58 mmol/mol) = 71.3%
HbA1c > 10.0% (86 mmol/mol) = 18.1%

(so only 7.4% of Type 1s achieve non-diabetic or prediabetic levels, however for T1s it is better to aim for good control in association with their consultant's advice rather than go for the same blood glucose targets as T2s with the associated risk of hypos).

Percentage of registered Type 2 patients in England

HbA1c >= 6.5% (48 mmol/mol = 72.5%
HbA1c > 7.5% (58 mmol/mol) = 32.6%
HbA1c >10.0% (86 mmol/mol) = 6.8%

(so only 27.5% of Type 2s achieve non-diabetic or prediabetic levels – we don't know how many of these depend on significant and increasing medication rather than diet however).

These results are very similar to those obtained in previous NHS audits over the past 5 - 6 years. 

Other FAQs

What about cholesterol?

Diabetics are right to be fearful of the risks of heart disease, since rates are many times higher than those of non-diabetics, especially if your Body Mass Index (BMI) is elevated.  GPs frequently use this to prescribe statins which, although they do reduce total cholesterol, come with their own baggage of controversy.  

Actually only around 80% of the cholesterol in the body is manufactured by the liver and the cells, and relatively little comes directly from the diet.  Furthermore, total cholesterol is now widely recognised as being a very poor indicator of heart disease risk.

Far more meaningful are the individual components (the lipid profile) of total cholesterol, especially the high density lipoprotein (HDL) and triglyceride levels.  The triglyceride/HDL ratio is perhaps the single most significant measure of heart disease risk.  The lower the triglycerides and the higher the HDL, the better.  A triglyceride/HDL ratio of 2 or less is a good target, 1.3 even better.

Insulin and glucose combine to raise triglycerides and lower HDL, which is why a low fat, high carbohydrate diet may actually increase heart disease risk.  It is commonly reported that those on low carb diets have better lipid profiles and certainly much improved triglyceride/HDL ratios, even though high carb diets can produce lower total cholesterol.

What about weight loss?

Reducing carbs (and the calories that go with them) is, together with exercise, also a good way to lose weight. Offset the carb calories with protein and fat calories in order to get the right balance for your personal situation.

Insulin is often referred to by biochemists as the fat building hormone.  In fact, the body cannot make body fat without insulin.  It is very unusual to find an overweight individual who doesn’t also have elevated insulin levels.  Type 2 diabetics, at diagnosis, will often be overproducing insulin.
Insulin also inhibits the body’s use of stored fat as a source of fuel.  Lowering insulin levels is extremely important, perhaps essential, for weight loss to succeed.  This is one reason why low carb diets are particularly successful in weight loss since the fewer the carbs, the less insulin is required.  Some may also find that they consume fewer calories without feeling hungry because their fat metabolism begins to work properly once more, allowing the body access to energy reserves in fat stores which were previously inaccessible.

What is ketosis? 

Ketosis is a perfectly natural and healthy state during which the body uses stored or dietary fat for fuel.  In order to enter this state, carbohydrate intake needs to fall below a certain level, typically around 50g/day.  Ideally, a healthy metabolism should regularly use ketosis, while fasting overnight for example, to fuel the body's processes and utilise stored fat reserves. 

(Ketoacidosis is quite different and is typically the result of a chronic lack of insulin, not a lack of carbohydrate). 

What about physical energy?

Strictly speaking, we burn neither glucose nor fat for physical energy.  Energy within our cells actually comes from a molecule called adenosine triphosphate, or ATP.  A glucose molecule will generate 36 ATP molecules.  A 6-carbon fatty acid molecule will generate 48 ATP molecules.  Therefore, when insulin levels are low and the body can access fatty acids as a fuel source, physical energy levels can actually increase on a low carb diet.

Anecdotally, many on low carb diets often report feeling considerably more energetic, without the peaks and troughs of energy which appear to come with a diet high in carbohydrates.

Is it suitable for Type 1 diabetics?

The benefits of reduced insulin levels also apply to Type 1s.  Insulin has a measureable impact on blood vessels by narrowing them, with increased cardiovascular risks.  Smaller doses can also make blood glucose fluctuations far more predictable, resulting in fewer highs and lows. It is not true to say that Type 1s need carbohydrates to feed their insulin, they may simply need less insulin.

Isn’t low carb just another diet fad?

Since the emergence of the human species in the Rift Valley around 3-4 million years ago, we have been meat eaters. Fruit and vegetables were a rare treat during their short growing seasons. We only began cultivating crops during the agricultural revolution 10,000 years ago. Refined sugars and starches became staples only around 200 years ago.

In the context of our evolutionary history, perhaps it’s the so-called ‘healthy balanced diet’ (aka  the 'Eatwell Plate') which is the real diet fad? 

Selected additional information and management sources

Book “Carbs & Cals” - contains photographs of foods and meals with carb, calorie, protein and fat values.

“My Fitness Pal” app – allows for logging meals and accounting for carbs and calories etc.

“Dietdoctor” website – www.dietdoctor.com/lchf

Jenny Ruhl - “Blood Sugar 101” http://www.phlaunt.com/diabetes/index.php

Dr Bernstein's Low-Carb diet solution.

This post and list of resources written and compiled by Rod aka Sanguine using additional original material written by Fergus Craig long term low carbing type one diabetic.