A healthy diet for prediabetes

A healthy diet for prediabetes explores the different options, the various philosophies about starches and the role of fat in weight loss; and the power of walking to lower blood glucose.

The diagnosis of prediabetes is the first difficulty. Many have normal fasting blood glucose and an unremarkable HbA1c test; yet their levels soar after a starchy meal. Unknown to both themselves and their doctors they are at risk of progressing to T2D. So there is no emphasis on the importance of a healthy diet.

They have what is now being called "intermediate hyperglycemia;" frequently undetected seriously raised blood-glucose after sweet and starchy meals.

  • Hyperglycemia - raised blood glucose
  • Hypoglycemia - low blood glucose

The diagnosis of prediabetes

The Diabetes Federation is now recommending the 1-hour 75g glucose tolerance test as the best way to identify these high risk individuals who fall under the radar of the more usual screening methods[1]. This is the opinion of a 22 member international expert panel; it's not to be taken lightly or summarily dismissed.

  • Those with a plasma glucose greater or equal to 8.6 mmol/L (155 mg/dL) after a 1-hour glucose challenge are prediabetic.
  • Greater or equal to 11.6 mmol/L (209 mg/dL) means you have frank type 2 diabetes.

"Should the plasma glucose rise above 8.6 mmol/L (155 mg/dL) one hour after the glucose drink they have intermediate hyperglycemia."

There are many different opinions and philosophies as to what constitutes a healthy diet for prediabetes. They are conflicting and contradictory; as usual, consumer beware. 

1. Carbs are bad

The first opinion is that all carbs are bad; period. Avoid them if you are prediabetic; and even more so if you have the frank disease. You should be eating less than 20 grams of starch per day.

Many but certainly not all supporters of the ketogenic diets would hold this view. That would mean no whole grains nor any legumes.

2. No, it's refined carbs that are bad

There is a subset of the ketogenic folk who would disagree. In their opinion it's refined carbs that are bad. So they would insist that whole grains and legumes are absolutely fine; as are new potatoes which have a large amount of resistant starch. Nevertheless the overall glycemic load should be limited; small helpings.

However let's acknowledge that true whole grains are not easy to come by.

The "big fat lie" internationally allows millers to describe their flour as whole grain, provided they have not extracted more than 40% of the goodies; the germ and bran.

wheat whole vs wholeAre these both truly wholemeal flour?

The germ contains the very important fats that amongst many other factors supply satiety. The management of hunger is central to prediabetes.

The fibre amongst many other factors slows gastric emptying; that is also so important in the management of prediabetes.

3. Strictly limit the fat

Prediabetes and obesity go hand in glove; strictly limiting the fat in a healthy diet for prediabetes is absolutely essential.

No, it's the saturated fats that contribute to the complications of diabetes; we should strictly limit all dairy products, red meat and even eggs.

No we disagree, it's the seed oils that are highly inflammatory and contribute to the heart disease associated with prediabetes.

You're all wrong. It is ever since Ancyl Keys in the late 1970s clearly cooked the books that prediabetes accelerated; he recommended we eschew animal fat and get our calories from carbs instead.

10 year diabetes rule

The long and the short of it is that there is simply no consensus as to what makes up a healthy diet for prediabetes.

There is universal agreement that avocados and olive oil are healthy fats. Hummus would be questioned by some followers of the ketogenic diets; made from chickpeas it does have some resistant starch.

Avocado and hummusAvocado stuffed with humus
Olives and olive oilOlives and the oil

The golden rule for prediabetes

The golden rule for prediabetes is that there is another way to limit the response of serum glucose to dietary starch. A short brisk ten-minute walk changes everything. The sugars entering the portal blood stream from the carbs we have just eaten are turned instead into glycogen in the liver to supply the muscles.

Those who are prediabetic should follow every starchy meal with a short walk.

"Neurologic Disorders are now the top global cause of illness and disability; and diabetic nerve disease is the fastest-growing of all these conditions.

- Lancet Neurology, March 2024

Fasting blood glucose

  • Normal is less than 5.6 mmol/L (100 mg/dL)


The HbA1c test give the average blood glucose over a two month period; highs from illness, exercise and fasting for example are smoothed out.

The test is more expensive than serum blood glucose tests.

  • Greater than 6.4% is considered diabetic
  • Between 5.7 - 6.4 is prediabetic
  • 5.6% and lower is normal


One great difficulty is that 30% of those with a raised HbA1c will have a normal fasting blood glucose; and vice versa.

Even having both tests will still miss about 25% of those with intermediate hyperglycemia; yet they are highly likely to progress to full blown diabetes.

1-hour 75g glucose tolerance test

The expert panel is now saying that a serum glucose value of 8.6 or higher after the 1-hour challenge is now considered the best predictor of whether a person is likely to progress to full blown diabetes.

It gives a firm diagnosis of "intermediate hyperglycemia;" despite the possibility of normal FBG and HbA1c tests.

Metabolic syndrome

  1. Abdominal obesity
  2. High blood pressure
  3. Impaired 1-hour GTT
  4. High triglycerides
  5. Low HDL cholesterol

Those at risk should have a coronary calcium scan.

A healthy diet for prediabetes

A healthy diet for prediabetes means limiting carbs, especially those that are refined; or exercising after starchy meals. Both together would be best of all.

Rule 1

A healthy diet for prediabetes absolutely must include strictly limiting sugar to 6 tsp per day and all refined carbs. Total starch should certainly be no more than 100 grams; and a lot less for those who are obese. 

It is without a doubt the most difficult rule; and breaking it repeatedly is the cause of the diabetes and obesity pandemic that is sweeping the world.

That means eschewing white rice, bread and cake flour; most pastas, refined corn grits and potatoes from cold storage too.

Those with prediabetes who break rule 1 are at very high risk of progressing to full blown diabetes.

Rule 2

Those who have been diagnosed with diabetes will also have to limit even the good healthy carbs like whole grains, legumes and butternut, for example until their 1-hour challenge GTT returns to the region around 8.6 mmol/L (155 mg/dL).

Rule 3

Take a short, brisk walk after every starchy meal.

The old lifestyle

The old lifestyle that got us into trouble in the first place has to change dramatically. This is not about dieting; it's a permanent whole new way of living. It has to include exercise after starchy meals.

The new lifestyle

The new lifestyle can almost be compared with a spiritual conversion. It begins with a new determination to honour our bodies as holy places.

Health in many ways remains pure mystery. All that happens is that turning to a healthy diet for prediabetes dramatically shifts the statistics in your favour; you are far more likely, yet not guaranteed to be able to enjoy a long and zestful life with little or no medication.

Healthy lifestyle

  • Body mass index < 25
  • Never having smoked
  • High-quality diet
  • Low commercial alcohol intake
  • Regular exercise
  • Adequate sleep

How does your lifestyle rate? If it's good then researchers have found you will have half the risk of Long Covid too.

Regularly enjoying these braised new potatoes would certainly contribute to a high-quality diet; planting, heaping and harvesting them will certainly contribute to regular exercise.

The prediabetes journey

The prediabetes journey will be for each of us unique, though common features will highlight the way. There will be a determination not to go straight from any starchy meal to the couch, computer stool or bed.

My own journey started with the shock discovery that a glass of freshly-squeezed orange juice shot my blood glucose up to 9.3.

My two greatest difficulties were giving up commercial bread, scones and cakes for ever; and taking a brisk walk after dinner. Discovering that natural honey had a low GI softened eschewing sugar.

The bread story actually reached back into the mists of time; watching college friends mill their own flour and bake their own loaves. Many years later I decided to emulate them and continue to do so to this day.

The result was the most delicious best bread in the whole world, baked with 100% wholemeal flour and using a sourdough starter.

The good news is that with a HbA1c now of 5.4 all anxiety has left; and at 75 both the good wife and I are busy, cheerful and going at life filled with enthusiasm and joy. It will inevitably one day come to an end.

But we continue to be diligent.

Here are some gems from a weight loss conference; some very helpful ideas from top physicians.

"We really want to be much more upstream by thinking of it as biologic disease and learning from cancer; and how it is much more about early screening and detection. Then, if you find something, reversing the biology and make it benign."

- Dr Mike McConnell, Clinical Professor of Medicine, Stanford

Typical breakfast that reversed my prediabetes

Typical lunch

Typical supper

Desserts are kept for high and holy days.

Strong research proves that type 2 diabetes can be completely put into remission without the use of any drugs by using food as medicine.

What are the warning signs of prediabetes?

There are so few specific warning signs of prediabetes; that's why it is so dangerous and 80% of those eating typical grocery store food are completely unaware that the Sword of Damocles hangs over their heads.

Fatigue is a common symptom but it pertains to so many other diseases; it's not specific.

Tingling and numbness especially in the feet should certainly be taken seriously.

Abdominal obesity is certainly a sign that all is not well; the organs are surrounded by "white fat."

If 80% of the population are suffering from this serious malady then everyone should have a 1 hour GTT periodically. Take a long walk once the test is over.

When you are prediabetic damage to kidneys, blood vessels and the heart will be starting. The medical advice is universal and simple; cut out the refined carbs and exercise more. Otherwise life will needlessly be cut short.


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  • ´╗┐Lifestyle and ideal body weight
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  • Pull the sweet tooth
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  • Refined maize meal and stunting
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  • Bake your own sourdough bread
  • Microplastics from our water
  • Alternative types of water storage
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  • Comfort foods
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  • Go to bed slightly hungry
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