I can tell you what these do in ME! YOU have to figure it out for how they are in YOU! In ME, glucose tablets start within a minute.
Fruit, a carb, starts within 5 minutes. And it depends which fruit.
Starches, carbs, differ. Cereal starts in about 10 minutes. Pasta in 20. Vegetables depend on how starchy they are, I guess. I get away with very little spiking with veg, minimal with squash.
Protein doesn't hit me til a couple hours.
Fat doesn't seem to change my blood glucose for 3-5 hours depending on what it's with. And then its a low mound, not a spike. If, however, I eat pizza, a combo of fat and starch with some protein, the fat slows down conversion of starch and protein. They hit in 3 hours.
If you only eat protein and fat, check your blood sugar in 2-3 hours and inject then.
If you eat only carbohydrate, it will start changing to glucose in 10-30 minutes.
If you give insulin and eat only protein & fat, you will get low blood sugar because the insulin acts before the protein and fat change to glucose. You will not see a change in blood sugar for the first hour after eating protein alone. But later on 50-60% of the protein changes to glucose. Takes awhile before it shows.
I have a pretty similar take to Leo2. Generally, all digestible carbs convert to glucose. Simple carbs, right away, within a few minutes, complex carbs (i.e. whole grains) longer, perhaps up to 1-2 hours. Carbs that supposedly cannot be digested are called fiber, however it turns out, most people actually digest significant portions fiber and your body absorbs this over a long period 3-6 hours as blood sugar and fat (yes, fat). Some people get a real blood sugar rise out of fiber.
Protein is absorbed over a 3-5 hours, some of which is absorbed directly as protein and the rest (as Leo2 notes, 50% or so) is converted to blood sugar. Fat eaten alone is directly absorbed as fat and causes no rise in blood sugars. Some people find that eating fat with carbs slows the digestion and enables a higher blood sugar rise. As a result, some historical ways of counting (like the TAG method) suggested counting 15% of fat as converting to blood sugar. Since I follow a low carb diet, I don't consider fat as contributing to any change in blood sugar.
Leo's a Type 1. I'm also T1 & experience protein & fat as he does. The effect fat has for me is slowing down digestion so that carbs & protein take longer to hit. I bolus for protein, but not for fat. You may be a good converter of fat to glucose, but it's still not a large percentage. Fat is calorie dense, of course, & go by grams not calories if you decide to bolus for fat content.
Musi - Are you saying 50 grams of walnuts by weight? That's about 6 Tablespoons?
Honestly I can't eat that many walnuts without trouble. Short acting Insulin doesn't cover it for me due to the time lag. Long acting isn't appropriate - lasts too long.
That many walnuts have 7.2 gm carbs, 9.6gm protein, and 28.2gm fat. On a 1:4 insulin:carb basis, I would need about 2 units early on, 1 unit in a couple hours, and a half unit in 3 hours. I usually solve the problem by eating a couple walnuts and stopping there! I have sworn a pact with myself not to let myself spike!
If you just count half the protein as carbs, then the total effective carbs would be 7.2 + (50% * 9.6), which is 12 grams. So if you have an ICR of 1:4, then you would need 3 units, two which you can take early on and another later. This technique is called an a split or extended bolus.
If you choose to use the TAG system (I don't, and I speculate that Leo2 doesn't either), then you would count 15% of fat as carbs. I don't.
Hi, I am very interested to know: HOW do you exactly know when will the carb start to take effect in your body?
Do you have a way to test it?
Fussy, you test with your meter.
I don'think there is an exact answer to this question. In my own experience for many years, you can eat the same exact thing at the same exact time every single day...and no two days will result the same. I have resulted low/high/perfect, for no good reason.
I think you can test and figure out when certain foods begin to "mix with blood", but don't forget that what you do each day can be a factor, stress and even elation can be factors, and just sometimes nothing at all can be a factor.
When you figure out the answer to this question, publish it...you will make millions!!