Hey everyone. I just ate a grapefruit and went down to 45 after it. It was one of those jumbo ones, and I ate both halves. I weighed it and it was 17 oz. and calorie king said for 17oz it would= 40 grams of carbs. I guess I overdid it…although my calculations are usually pretty accurate when I weigh things. Is grapefruit just weird…like I know it’s a diet food so does it have some weird glucose lowering effect? Or, does anyone else have an accurate count for those large grapefruits?


Just a word of caution guys.
Grapefruit juice is notorious for increasing blood levels of many drugs!
This can then bring the drug levels in the blood to very toxic and very dangerous levels.
Not trying to frighten you.
All you need to do is check with your pharmacist/ doctor if you can eat vast amounts of grapefruits/ or juice with the meds you are taking.

cholesterol lowering meds is one of those suggested by my Pharmacy NOT to mix with diabetes and GRAPEFRUIT /G.JUICE …Micheal : thanks for mentioning this here !!

Grapefruit is actually one of those fruits that I still will occaisonally have. Grapefruit has a ‘relatively’ low glycemic index, compared to a fruit such as orange. It is markedly acidic, which also affects you processing of the carbs (in a good way). And finally, the sugars in grapefruit are ‘more’ healthy, actually having less fuctose than glucose, thus the carbs that are in grapefruit are metabolized better than even table sugar.

The best thing to do, is develop your own ‘factor’ for grapefruits. Also, when I look up a large (4.5") raw grapefruit in fitday, it comes out as 26.8 g carbs, 3.7 fiber. And one thing to remember when using these calculators is that many use the weight of the ‘meat’ of the fruit, not accounting for the weight of the skin and core.

Hope that helps.

I noticed this effect too. Lot of water, acidity, and like bsc said, a pretty low glycemic index. I only half of one when I do, and I count it as 10 carbs; has worked well for me. But like we always say, everyone is different! Trial and error I guess.

Thanks everyone. I will definitely just have to cut back until I find that magic number. Your responses were helpful!

I talked to my drs and pahrmacists about this–it depends on how much Grapefruit you have with which drugs. I have a grapefruit a day ( I prefer the pink ones) if I can’t get fresh I buy canned…no odd impact to my BG (I weigh for carbs) and no prob with my pravastatin/insulin