Plant-Based Diet in the Treatment and Prevention of Diabetes

  • Diabetes is a disease of the blood vessels. If one’s blood sugars are too high too often, one’s blood vessels become damaged and inflamed – putting one at high risk for heart disease, kidney disease, blindness, amputation, and infections.
  • Having high blood pressure and being overweight as well as having diabetes, worsens these risks.

Diabetes explained

Diabetes Mellitus is a condition where the body is unable to move glucose (sugar) from the blood to the body cells where it provides the energy required by these cells. Typically, after food containing carbohydrate is eaten, it is broken down by digestion to glucose which is then absorbed from the intestine into the bloodstream as blood glucose (S-glucose). The pancreas then secretes the hormone insulin, which facilitates uptake by the body’s cells of this glucose – which then provides the cells with energy (fuel).  Insulin is effectively the KEY that unlocks the body’s cells to allow the blood glucose in. In diabetes, insufficient / no insulin is secreted – so glucose is not efficiently moved from the blood to the body cells.

The result is:

A huge depletion in energy, extreme thirst and long-term complications including nerve damage, blindness, kidney disease, stroke, amputations.


By constant monitoring of blood glucose levels (keep them between 4-6mmol/l) and GOOD DIET and LIFESTYLE, the complications are totally PREVENTABLE!

There are 2 types of Diabetes Mellitus:

  • Diabetes Type 1   (5% of all diabetic cases)
  • Diabetes Type 2   (90-95% of all diabetic cases)

Type I Diabetes

  • The beta cells of the pancreas are unable to produce insulin
  • Usually a sudden onset
  • There is usually a pre-existing genetic component, as well as a precipitating trigger, e.g. a viral infection or a stressful or traumatic episode.   
  • Insulin needs to be injected daily – to mimic the action of the insulin produced normally by the pancreas.

Typical symptoms include:

  • Chronic thirst
  • Chronic urination
  • Chronic hunger
  • Sudden weight loss despite taking in extra food and drink.

Treatment of Type I involves:

Insulin, dietary changes, and exercise. It is HIGHLY recommended that one is treated by a Team including Diabetic Educator/Nurse, Dietician, GP as well as an Ophthalmologist and Podiatrist, and others as recommended by your Medical Care Team.

Type II Diabetes

  • The pancreas becomes less effective, usually due to overweight, insulin resistance, high cholesterol and /or high triglyceride levels and high blood pressure.
  • Slow onset
  • Ranges from relative insulin deficiency through to absolute insulin deficiency.

Typical symptoms often (not always) include:

  • Chronic infections
  • Chronic fatigue
  • Pain/cramps/burning sensation in legs and feet
  • Shortness of breath
  • Blurring of vision

Treatment of Type II involves (depending on the level of insulin deficiency):

Dietary changes, exercise and if necessary medication/insulin. Once again involve your complete medical team including Diabetic Educator/Nurse, Dietician, GP, Endocrinologist as well as an Ophthalmologist, Podiatrist, and others as recommended.

Insulin Resistance

INSULIN RESISTANCE and obesity are the leading causes of Diabetes Type 2.

But what is Insulin Resistance?

Insulin is the hormone produced by the beta cells of the pancreas to transport glucose from food to the cells of the body. Insulin is the key that unlocks the cells of the body to allow the glucose (energy source) into the cells. Each time you eat, the pancreas produces insulin to pick up the glucose (much like a coal truck transports coal) and moves it into the body’s cells for use as energy. Without insulin, the cells cannot accept the glucose. In addition, if the cells are blocked/clogged up with fat, insulin (the key) cannot unlock the cell to allow the glucose in. In both cases, if glucose cannot get inside the cells, it builds up in the bloodstream….causing damage.

Insulin resistance occurs when the body becomes resistant to insulin’s effects.  The pancreas DOES produce insulin, BUT the accumulation of FAT in the muscle and liver cells INTERFERES with the action of insulin. This fatty build-up creates toxic breakdown products and free radicals that cause inflammation and block the insulin signalling process. This fat comes either from the fat you EAT or the fat you WEAR (body fat).

No matter how much insulin is produced by the pancreas, the fat-compromised muscle cells cannot effectively use it. 

As such, the PREVENTION, TREATMENT and REVERSAL of Type 2 Diabetes are therefore dependent on DIET and LIFESTYLE.

Meal Planning in Diabetes

A good diet is one of the most powerful tools you have to control your diabetes.

Eating correctly will help you:

  • Control your weight
  • Control your blood glucose levels – keeping them consistent, which reduces/prevents the risk of developing complications substantially!
  • Improve insulin sensitivity in Type 2 Diabetes;
  • Control blood cholesterol and triglyceride levels
  • Feel good
  • Improve your overall health

The food you eat directly affects your blood glucose levels

The 2 nutrients that have a direct impact on blood glucose levels are CARBOHYDRATES and FATS.


Carbohydrates are digested and broken down to GLUCOSE. Glucose is the body’s FUEL = ENERGY source, and as such, it is vital to understand that not all carbohydrates are bad!

Carbohydrates are found in breads, cereals, pap, pasta, rice, potatoes, mealies, legumes, vegetables, fruit, sugar, cakes, pastries, crisps, popcorn, sweets, fruit juice and cold drinks.

Not ALL carbohydrates are digested at the same rate: some are digested super-fast causing a spike and subsequent dump of blood glucose levels (High GI carbohydrates); while others are digested slowly – providing a slow, steady release of glucose from the intestine into the bloodstream (Low GI carbohydrates).

The “Glycaemic Index” (GI) is a measurement of how quickly a food containing carbohydrate is digested to glucose and then absorbed into the bloodstream – relative to pure glucose (GI = 100).

The rating scale for the GI is 1 – 100:

  • Foods with a GI > 70 = HIGH GI
  • Foods with a GI < 55 = LOW GI
  • Foods with a GI between 55 and 70 = INTERMEDIATE GI.

High GI (quick-release carbohydrate) foods spike and dump blood glucose levels within 30-60min of eating them. These foods worsen insulin sensitivity, cause extreme fatigue and lethargy, and also cause increased fat storage (simply put: excess blood glucose is removed to the liver, which converts it to body fat).

Examples of High GI carbohydrate foods:

  • White / brown (light, fluffy) breads & bread rolls
  • Rice cakes, snack breads, biscuits, pastries, cake
  • Refined breakfast cereals and mealie meal
  • Most sports/energy drinks, unless labelled Low GI, and sweetened cold drinks
  • Sweets, chocolates, crisps
  • Cake flour, cornflour, sugar, honey, jam

Low GI (slow-release carbohydrate) foods are broken down slowly, causing a slow, gradual, steady release of glucose into the bloodstream.  Less insulin is therefore required for uptake of this glucose, and so blood sugar levels remain consistent for far longer – resulting in energy levels also being sustained for far longer.

These foods ARE IDEAL CHOICES – and should be included every 3 hours in your diet in controlled amounts.

Examples of Low GI carbohydrate foods:

  • Heavy, high fibre breads (seed loaf, “health” bread, rye bread), Low GI breads
  • Wholegrains, e.g. durum wheat pasta, brown rice, mealies, sweetcorn, baby potatoes, sweet potatoes
  • Breakfast cereals, e.g. Soya Life Porridge (Dischem), Hi-Fibre Bran, Oat Bran, whole food muesli
  • LEGUMES: soya, baked beans, lentils, green beans, butter beans, chickpeas, kidney beans etc
  • Most fresh fruits and vegetables
  • Low-fat milk and plain yoghurt
  • Popcorn
  • Soya Life Instant Meal Replacement Drink (Dischem)


It is a fact that a high-fat diet can impair the body’s ability to handle glucose. The good news is that by reducing one’s FAT intake, one can lower insulin resistance. Research shows that as the amount of fat in your diet is steadily reduced, so insulin works increasingly better!

Not all fats affect our muscle cells in the same way. For example, palmitate – the kind of SATURATED fat found in meat, dairy, and eggs – causes insulin resistance, and worsens diabetes control. While oleate – the MONOUNSATURATED FAT found in nuts, olives, and avocados – actually PROTECTS against the detrimental effects of saturated fats.

Plant-Based Diets

A plant-based diet, which includes mainly unprocessed plant foods, and minimal (if any) animal foods, eaten at regular intervals throughout the day is a diet that is automatically low GI, low in saturated fats and contains monounsaturated fats (protective), and as such is the ideal diet to follow when managing or preventing diabetes.

Research shows that those eating plant-based diets have been found to have better insulin sensitivity, improved blood glucose levels, improved insulin levels AND improved function of the beta cells of the pancreas (the cells that produce insulin). In other words, people eating plant-based diets appear to be better at both PRODUCING and USING insulin!

Legumes are an essential part of a diabetic / pre-diabetic diet:

Interventional research trials show that when large groups of individuals with pre-diabetes or insulin resistance were split into two groups:  one group eating 1kg of any form of legumes per week over and above their normal diets vs the other group cutting calories by 500kCal/day – that the legume-eating group lost belly fat and improved blood glucose control just as effectively as the calorie-cutting group, and gained extra benefits such as lowering cholesterol levels and improving insulin sensitivity. In other words, better health was achieved by improving the QUALITY of their foods by eating legume-rich meals.

Plant-based diets result in one getting better as well as feeling better. People with diabetes following a plant-based diet report (in a recent randomized, clinical weight-loss trial) both a significantly better quality of life and significantly improved mood than those following a conventional diet. Other advantages include:

  • Eating vegetable and legume foods results in one being less likely to binge (on the wrong foods)
  • Plant-based diets result in one feeling less hungry.

As such, a plant-based diet is more sustainable and easier to adopt as a long-term way of eating, especially when trying to lose weight.

And yet the beneficial effects of eating a plant-based diet extend beyond weight loss for those with diabetes: Studies have shown that when one switches from a conventional diet plan to one that is purely plant-based, insulin requirements drop by 50-60% in under a month, and HbA1C levels drop to below 6% in 2-3 months.

Note: all dietary changes one makes should be done in consultation with your Dietician, and insulin/medication changes in consultation with your Diabetes Educator (especially when it comes to reducing insulin or medication).

Manage/Prevent Diabetes:

  1. CONTROL your blood sugar levels and test them often: ideal = 4-6mmol/l
  2. LOSE weight if you are overweight!
  3. DO regular exercise
    1. Use LOW GI, HIGH FIBRE foods EVERY 3-4 HOURS to keep your blood sugars stable and to keep you feeling “full”.
    2. Go Plant-based! In other words, eat 90% or more plant-based food choices, including:
      1. All-you-can-eat greens
      2. LOTS of other vegetables (fill half your plate with vegetables of different bright colours: red, orange, green);
      3. LOTS of beans and legumes (include these in meals and snacks)
      4. Wholegrains
      5. Fruits (2-4/day – spread throughout the day)
      6. Nuts and seeds
    3. ELIMINATE refined grains, junk foods, oil, and salt
    4. Restrict animal product consumption (including meat, poultry, fish, eggs, and dairy)

A typical Daily Plant-Based Eating Plan that one could use for starters:

  • Have Soya Life Porridge / Oats porridge  with a serving of berries/other fruit
  • Have at least one enormous salad per day (with LOTS of different veggies and seeds. You can even add chickpeas/kidney beans)
  • Have one serving of a veggie-bean/lentil soup
  • A handful of nuts and seeds
  • Fruit at every meal
  • 500g cooked green veggies
  • Some whole grains (e.g. oats, low GI bread, brown rice)

Consult your dietician to help you with menu planning, meal ideas, recipes – appropriate for your condition, level of diabetic control, weight, levels of activity, likes/dislikes, working conditions etc.

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