Proof That a Raw Fruit Diet Does NOT Cause High Blood Sugar

Proof that a raw fruit diet does NOT cause high blood sugar

One of the most common reasons I hear against adopting a raw vegan diet that is low in fat and high in fruit is that the sugar from the fruit leads to elevated blood sugar levels.

If this is true, it is very serious. Sustained elevated blood sugar levels, meaning blood sugar levels that remain elevated long after finishing a meal, is the defining element of Diabetes Type II.

But is it true? Does a low fat raw vegan diet that’s high in fruit (at least 80% of total calories coming from carbohydrates) and low in fat (no more than 10% of total calories from fat) really lead to elevated blood sugar levels and possibly Diabetes?

Rather than pontificate about the possibilities, I decided to test it for myself.

First, some background information:


A normal fasting blood glucose level ranges between 70-99 mg/dL (milligrams per deciliter).

A normal 2-hour postprandial (2 hours after eating) blood glucose level ranges between 70-145 mg/dL.

Someone with a fasting blood glucose sample above 126 mg/dL is considered hyperglycemic (high blood sugar).

Someone with a fasting blood glucose reading below 70 mg/dL is considered hypoglycemic (low blood sugar).

Actually, some values are more lenient than this. The American Diabetes Association recommends a fasting glucose reading range of 90-130 mg/dL and a postprandial reading of 180 mg/dL or less.

The Tests

Each day for seven days, I took three blood samples using the FreeStyle Freedom Lite Blood Glucose Monitoring System. Each test was performed on my left forearm.

First, I took my fasting blood glucose sample before breakfast. This was taken roughly twelve hours after my last meal.

Second, I took a sample right after I finished breakfast. Each sample was taken less than two minutes after my last swig of smoothie.

Third, I took a sample two hours after eating.

The Food

The test meal, which was my breakfast, I kept the same each day. I ate 8 medium bananas blended with water.

Lunch was also a fruit meal, either more bananas, grapes, gala apples, or oranges.

Dinner started out with more fruit, followed by a large salad of lettuce, cucumber, tomatoes, and 1 ounce of raw nuts.

My average macronutrient ratio over the seven days was 86% carbohydrates, 6% protein, and 8% fat.

The Results

Here are my results.

I took a total of twenty-one blood samples (7 fasting, 7 right after breakfast, and 7 two hours after breakfast) over a seven day period:

Wednesday, January 12

Fasting: 94 mg/dL

Right After Breakfast: 132 mg/dL

2 Hours After Breakfast: 113 mg/dL

Thursday, January 13

Fasting: 90 mg/dL

Right After Breakfast: 113 mg/dL

2 Hours After Breakfast: 108 mg/dL

Friday, January 14

Fasting: 84 mg/dL

Right After Breakfast: 92 mg/dL

2 Hours After Breakfast: 125 mg/dL

Saturday, January 15

Fasting: 93 mg/dL

Right After Breakfast: 119 mg/dL

2 Hours After Breakfast: 109 mg/dL

Sunday, January 16

Fasting: 89 mg/dL

Right After Breakfast: 95 mg/dL

2 Hours After Breakfast: 111 mg/dL

Monday, January 17

Fasting: 87 mg/dL

Right After Breakfast: 105 mg/dL

2 Hours After Breakfast: 115 mg/dL

Tuesday, January 18

Fasting: 90 mg/dL

Right After Breakfast: 94 mg/dL

2 Hours After Breakfast: 112 mg/dL


Average “Fasting” Reading: 90 mg/dL

Average “30 Minutes After Breakfast” Reading: 107 mg/dL

Average “Right After Breakfast” Reading: 99 mg/dL


All 21 blood glucose samples that were taken were within the normal range. These results present no evidence that a low fat, high fruit raw vegan diet leads to hyperglycemia.

My Thoughts

The results are clear as day. A healthy raw food diet that is high in fruit and low in fat does NOT lead to elevated blood sugar levels. Even less than 2 minutes after finishing an 800+ calorie meal of bananas, my blood glucose level was well within the normal range.

And I’ve been eating this way since 2007. If a raw fruit diet really caused high blood sugar, I would be hyperglycemic by now!

So what does raise blood sugar levels? Stay tuned for my next post to find out! :)

Go raw and be fit,


P.S. Looking for tasty AND healthy raw vegan recipes to help you adopt a healthy – but totally “dangerous” :roll: – low fat raw vegan diet?

Check out my 100% raw vegan recipe e-book:

“Low Fat, Fruit Filled, High Fun Raw Recipes”

Delicious and Healthy Raw Vegan Favorites for Every Meal


  1. Hi- I think it’s great that you used blood sugar testing, but everything I’ve ever read says it takes at least 15 minutes for blood sugar to reach its highest point after eating, even if one is eating pure glucose. The purported average for different people and different types of food seems to be an hour to reach the highest reading. So I don’t think the “right after breakfast” readings are useful. If you ever do a test like this again, though, I’d be interested to see the results, especially if you include a reading at 30 minutes or so.

    Swayze Reply:


    Please check out my video here:

  2. So you would get the necessary protein and b12 vitamins from eating a lot of fruit?

    Swayze Reply:

    Hi Sophia,

    Check out this article on protein:

    B12 deficiency is hotly debated, but a good place to start is the book “Could It Be B12?”:


  3. As always, great post and you are right on.

    You always have been the voice of reason for me. Thank you!

    Swayze Reply:

    Thank you, Chris! :)

  4. I was wondering – is it true that people process sugars differently? I have a colleague who was laughing at me eating 6 oranges for breakfast this morning (my work desk looking like a produce stall gets no end of comments).
    He said “that’s gonna give you a sugar buzz for a while”, and when I said “not at all” he said “it would do that to me”.
    I showed him your very well-timed article/experiment, and he said “different people must process sugar differently”.

    What are your thoughts on this?

    Swayze Reply:

    Tell your colleague to try limiting his fat intake. His issues with fruit are caused by excess dietary fat, not sugar.

    Bob Reply:

    85% of people with European and “rice culture” ancestry have the capacity to process high quantities of carbs. And provided that the diet is calorie restricted, your advice will work. There are many populations ( Pacific islanders, and many others ) and the 15% of Europeans who do not have the genetic machinery to process carbs like you do.

    For example, I followed a very low carb diet, which was calorie restricted ( ~1500 / day ) but a Vegan’s nightmare. And dropped fasting and post meal blood glucose from ~135 mg/dL to 90-100 mg/dL for months. Lost 30#. All without changing exercise. After trying your approach for 2 weeks, very strictly, my blood sugar levels INCREASED to ~125 mg/dL. Why? Because I am insulin resistant, which is an adaptation for a carbohydrate scarce environment. It forces what little carbs you eat to your vital organs rather than adipose flesh. The problem with this state of affairs is when you eats lots of carbs, they build up in the blood – they have no place to go.

    Pacific islander, Australian aboriginal peoples, and many of the type 2 diabetic europeans, will, in fact, elevate their blood glucose levels, sometimes dramatically, on a fruit heavy diet. This has been proven over and over in large scale studies in Australia.

    The new USDA guidelines support materials / studies basically echo this. Inferring that MOST people can tolerate fruit sugars, but for obese individuals this is not true. Hint: the OTHER people are obese and diabetic.

    I see this mirrored in my own children. One is a cute little toothpick who eats tons of fruit, sugars, and so on. The other is very obese, and gains weight any time sugars are admitted into his diet.

    Your assumption that because it works for you, an ( excuse the label ) vegan toothpick, and presumably someone who has never weighed 300#, does not mean it works for everyone. And very often people who are obese are not type 2 diabetics. My wife is 300# and has incredible glucose tolerance and fasting glucose of 70! In fact so much so her doctor can hardly believe the results. But what SHE is good at is sequestering glucose as fat. In other words, she is insulin sensitive.

    My issue is WHAT I’m eating, her issue is the she IS eating.

    This splits the population into TWO types. Insulin sensitive, who can process large quantities of carbs, and insulin resistant who cannot. A calorie restricted diet, of course, lowers blood sugar, but does not address the underlying issue.

    My suspicion is that those who are insulin sensitive ( carb eating phenotype ) cannot tolerate fats as well. And insulin resistant individuals ( Type 2 diabetics ) the opposite is true. Hence the results you find hold true for many.

    The key is to reduce calories below that needed to force the liver to generate glucose. That the entire glucose capacity of the body is about 5-10g ( the amoun in solution at any time ) means that drinking a glass of orge juice is largely stored immediately, then re-released. That requires insulin. Those with impaired insulin function will suffer on your diet – as I did Healthy individuals may be able to tolerate it, if they are endowed with the proper ticket from genetic lotto.

    But do not, for a moment, believe that you have discovered a universal truth.

    BTW, just a week back on the low carb, meat lovers – and certainly a LOT of veg too – diet ( but calorie restricted to 1500/day ) I am again back to sub 100 mg/dL fasting and ~100 average glucose reads.

    So just a cautionary tale. I would suggest that anyone suspecting impaired glucose function to get a meter and tart taking readings – especially the fasting reading in the morning and 3 hours after a meal. If they can tolerate an 80% carb diet, more power to you! But my suspicion is that many truly obese individuals will find your diet a disaster. They need to monitor their progress.

    I’m of the opinion that any diet that lowers blood glucose is a good diet – and as a practical matter, your diet works on the basis of being calorie restrictvie, rather than the magical power of veganism. I would only argue that it is far better to measure progress in terms of blood sugar reads before ingesting 1000 calories of sugars.

    Swayze Reply:

    Hi Bob,

    Several people have lost 100+ pounds eating a low fat raw vegan diet. Here’s just one example:

    And I definitely don’t eat 1000 calories. I eat over 2000 calories every day and was eating about 2600 during the 7 days I took my glucose readings.

  5. Hey Swayze,

    I have experimented with my blood sugar readings also and have come up with similar readings well below the maximum range while eating a variety of different meals including the so-called high glycemic fruits like dates and grapes.

    Swayze Reply:

    I believe it! I tested my Mom recently, who eats a low fat cooked vegan diet with lots of fruit, and her reading was well within the normal range as well.

    Lucas Reply:

    I have a friend who is severely overweight and Type 2 diabetic. I suggested he cut back on all overts for 3-4 days before starting and LFRV diet. He called back amazed after one week and could believe he was able to keep his blood sugar under control while eating 200+ grams of sugar(fructose) in his meals.