When you eat fruit, do your glucose levels go up?

My wife tests her blood four times a day. Frankly, she seems to avoid eating fruit because she worries about getting high readings or even glucose spikes from the fructose in the fruit. However, I think we all agree that fruit is an essential ingredient in any diet. Basically, if she eats fruit with some or all of her meals, what can she expect? If she gets spikes, can her body deal with them more easily because the sugars in the fruit are natural, not refined? Finally, if she gets spikes, perhaps from the fruit, should she worry about them? She worries about needing more insulin due to high readings or even spikes. Any advice or information given is greatly appreciated.

Hi Marad,

The only way she’ll know how fruit effects her is to test after eating some & to try a variety of different fruits. Some fruits contains a lot more sugar than others. Everyone is different regarding what causes spikes, so other people’s experiences won’t have much bearing.

Fruit isn’t an essential part of diet. The same basic nutrients are available in vegetables without the fructose. Sugar being natural doesn’t matter. It hits the bloodstream whether it’s fructose, glucose, sucrose, with meals or by itself.

Spikes are not good! Your wife is wise to be concerned & to avoid foods that increase her BG. Yes, she’ll need more insulin to either bolus to prevent spikes, or to correct highs after the fact.

I’m Type 1 & can’t handle fruit, with the exception of very small quantities of berries which aren’t very sweet. It’s not worth it to me to take the amount of insulin needed to cover fruit.

Don’t give up on fruit, they are one of the most perfectly suitable foods for humans, it’s all about trial and error. I find that fruit doesn’t affect my readings that much, not even great for lows either. They are so good for us, i think they really need to be included in our diets.

Berries: strawberries, blueberries, blackberries, raspberries don’t raise blood sugar much because they are pretty low in carbs. I don’t know if you get those fruits where you are though. But you will in Canada.

Here is a discussion we had on this topic that you may be interested in reading.

I eat berries ( raspberries, blueberries, black berries and strawberries). I usually limit it to 1/2 - 3/4 cup - usually under 10 carbs. Things like apples, banannas and peaches I’ll only eat 1/2 and always eat with a protein or a fat to slow absorption. I know some people like Dr Bernstein don’t eat fruit or a lot of veggies like tomatoes, peppers and onions. But that is too restrictive for me. Fruits have a lot of antioxidants in them. I never drink fruit juice. The only juice I drink is low sodium V-8 juice.

My niece is Type 1 and often asks for fruit for desert. I would much rather give her a small bag of potato chips or icecream because they do not effect her blood sugars and fruit does. Crazy, isn’t it that you would prefer to give junk over fruit? Since she counts carbs and covers with insulin, I give her the fruit, even fruit salad (mixed fruit, tiny bit of splenda and few tablespoons of cold water mixed). When she gets hooked up to her cgms, I will do an experiment (though that will not tell you what it will do to you, personally, you may have a general idea. Since I take blood sugar usually two hours post, and it may be okay, that is not to say she does not spike very high in one hour after eating fruit. On the occasions I do check one hour post prandial, it is because I suspect lows, so have never really seen what fruit does in real time.

Dear Marad.

Yes her BG will go up a lot depending on which fruit she eats and how ripe it is. For example I had a bowl may be 200 grams of mixed frozed fruit consisting mostly of peach and I also ate 50 grams of dried raisins and I forgot to inject insulin to compensate for this and one hour after eating my BG was 230 not good.

Probably things to avoid are the dried raisins, dates, figs, very ripe bananas, mango, pineapples(?). Better are apples and not so ripe bananas. Eating a small orange is better than orange juice.

You can look up on the net the glycemic load of different fruits and have her try the lowest ones and she can measure her BG one hour and two hours after eating a portion and she might discover something that is acceptable.

When I eat fruit and cover for it I actually get low. Fruit juice isnt fruit so you cant compare the two. If you eat fruit with something else then its not the fruit thats making you high its the other thing you ate or you didnt do enough insulin for the fruit you ate. Fruit is a really good source of carbs and other vitamins and minerals, make sure its organic though. I can eat a lot of fruit and cover for it based on how many carbs it was and I always end up getting low, so I do less insulin when Im eating fruit.

Hi Marad, I have found by testing that some fruits I need to stay away from, tangerines for one, some I can do in limited amounts, 1/2 a banana as a breakfast, and others I can go to town on, strawberries seem to do nothing to my BG. Cantaloupe and watermelon I can do a lot but I still see an increase. A guy I work with can not do cherries, he told me 4 cherries and he spikes, so I treat them with respect and do 1 once in a while.

Yes, I agree that everybody is different.
For me, if it’s a serving that contains 15 gm or less of carbs, I can eat all berries, apples and oranges with no problem. I do not handle bananas and pineapple well. Juice I only use for hypos, and dried fruit is too concentrated.
It also depends on what time of day I eat them. I have huge insulin needs in the morning, until about 10 a.m, and then it slowly decreases throughout the day. So if I were going to have a bowl of raspberries, it would be a wiser choice to have them in the evening than on my breakfast cereal.

The price of eating something sweet (even fruit) before taking a driving test can be big. The last time I reapplied for my driver’s license, I had a peach before going. I got to the eye test portion, and failed…why because I couldn’t detect which signs were close and which were farther away. I had my reading glasses on…and my eyes were affected by the sugar in the peach. NUTS! I asked the opthamology docs if that could do it, and he said of course, the peach and it’s sugar caused my eyes to swell slightly and that was the culprit. They wouldn’t let me do the test over, so for the last three years I have had to wear glasses, which I don’t need in order to legally drive the car. Yep, fruit will cause a rise in your BG’s. But when you consider that just about anything we eat can and will do that for people, fruit is still a better choice than a double dip ice cream cone.