Weighing carbs cooked uncooked?

I’ve come across something curious upon my carbs experimentation lately-wondering if anyone else has too!
I eat relatively low to mod carb and weigh what I do eat. I’ve recently been experimenting with sweet potato. Turns out if you weigh it raw (165g) = 23ishg carbs. But if you then weigh that same portion cooked it becomes around 55g weight which = roughly 8g carbs to bolus for!?

I’ve found that if I bolus for the cooked amount I go high postmeal. Tonight is first night of bolusing for precooked amount eliminating other variables in meal (other nights I’ve gone low bolusing for the raw amount).

It’s so experimental isn’t it!

This is actually an interesting question. Raw foods don’t come with a nutrition label. But you can look up their nutrition.

And the nutrition varies with the preparation. The carb content per weight varies from raw and cooked. And preparation matters, for potatoes that you cook and then cool and eat cold some of the carbs actually convert to fiber reducing the carbs.

In the case of something like the sweet potato you can look up the cooked nutrition but you have to be careful that the preparation makes a huge difference in how much water is retained. Boil them and you probably retain the water and the cooked weight is similar to the raw weight. Roast or bake the sweet potato and you may lose significant water and weight, which I suspect is what happened to you.

ps. If you look up the carb content of raw and cooked sweet potato they are basically the same. So you would expect your cooked version had about 23ish carbs.

Yes- I had thinly sliced and roasted it. Removes my wanting to slather it in butter! Bolused for the precooked-23g. Seemed to work ok! Did go low later but more than two hours later and suspect my basals need some adjustment.
I use the Calorie King app for nutrition on veg :slight_smile:
There are some foods for me I know I simply have to slightly over bolus for-perhaps this is why!

Another wrinkle that makes the calculations more challenging: many foods, starchy ones in particular, have more available carbohydrate when cooked than when raw. The cooking process causes actual chemical changes. Most “smart” scales take this into account—they will report a higher carb count for a cooked food than for the equivalent weight when raw.

And, of course, some foods actually gain water when cooked, complicating the equation still further.

Hey, if it were easy, anybody could do it. Diabetes doesn’t change only challenge the body; it challenges the mind, too. :wink:

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That’s it! It does give another argument for ultra low carb doesn’t it!
I still like knowing how to manage some though-with family dinners or simply a ‘hungry’ moody eating day haha.
Diabetes has definitely taught me how to be more patient!! Except when I’m not :smile:

You might actually do better when it is slathered in butter, to slow the carb absorption…

I personally don’t do starchy veges… too hard to predict their response… l/c / keto-girl I am.

I really like other vegetables slathered in butter and / or sour cream… oh… it’s nearly dinner time…


That’s a great point actually! It’s amazing what we forget for ourselves when we’re so ‘in’ it!

Most of the published carb info for raw ingredients. If there are separate ratings for cooked vs raw foods (e.g. USDA info that shows up when you search Google for something like “sweet potato carbs”), those items will be called out separately (e.g. baked, mashed, boiled). When you cook food, not only do they change chemically (e.g. sugars changing state through caramelization), but you can also be cooking off a lot of water weight (which is probably why OP sees such a change in weight – you must be cooking the heck out of those).

Seems easier to weigh ahead of time and use carb factors (e.g. raw sweet potato has a carb factor of 17-20%, depending on how you count fiber), then you’re not worrying about how much water you’re cooking off, adding in, etc.

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I’ve only recently (last two days!) found out about carb factors. I love this idea. Do you know any good places for accessing these? Apps etc?
Yeh…I sliced it super thin and roasted it-like chips! Yum yum :blush:

Carb factors won’t help adjust for cooked versus uncooked foods or from dried/dehydrated versus raw. Carb factors are just a simple way to weigh your food and then calculate the carbs. You can get your carb factor by looking up the nutrition information such as here for a raw apple, which gives the carb content for a regular 100g serving. The carb factor is simply the carbs (subtract the fiber) (13.8-2.4 = 11.4) from the nutrition table divided by 100 which gives the proportion of carbs in a gram of the food. In this case is 0.11 for a raw apple.

Oh that’s nice and simple. Thanks for that!
That’s an incredible breakdown of food nutrition-will be bookmarking that one for sure.