Should Starch be Counted as a Simple Sugar?

The cereal I just bought has 12g of sugar and 31g starch per serving.

My previous cereal didn’t breakdown the starch, so I am wondering if I accidentally bought a 43g sugar per serving cereal. I wish they listed the glycemic index on food, that would make it obvious which foods are better. I don’t need to monitor my sugars, but I prefer to choose foods that have a lower GI.

Does starch digest as quickly as a simple sugar?


No idea what the official slant is, but I count them as the same, unless I know that the carb in question is low glycemic absolutely … I know how my body reacts to my favorite oatmeal, but if someone hands me oatyos death in a box, I am going to treat them as high glycemic munchies until I see how my body reacts.

Whoa there! A single serving is how many grams? Usually, there are only 28 grams per ounce, and most serving sizes are done on a per ounce basis.

The glycemic index is quite controversial. For example, carrots for years had an extremely high glycemic level, but they were obviously good for you. Ends up the people they measured had to eat about 2 pounds of carrots each to get the required amount of starch. Walter Willett came up with the term Glycemic Load which takes the glycemic index and divides it by the serving size. That gave carrots a much lower number. A few years later, a new study found that carrots really didn’t have that high a glycemic index anyway. The original study was mistaken.

The problem of the glycemic index is how complex it is to measure. A typical measurement involves about 10 to 20 people (usually college students). They have to first fast and have their baseline blood glucose level measured. After that, they are fed a fixed amount of pure glucose or sucrose (depending upon the scale), and their blood glucose levels are measured again several times for two to three hours.

That is for the baseline. The same subjects must come back later to actually test the actual substance. Again, they fast, and are fed a specific amount of the substance being tested. The amount fed depends upon the starch level of the substance. The lower the starch level, the more they much eat. Low carb foods such as meat are not measured because the amount a person would have to eat would be enormous.

After consuming that substance (which must be eaten in a set amount of time), the subjects blood glucose levels are measured at fixed intervals. The results of that are compared to the previous glucose/sucrose measurements, and averaged among the subjects. That becomes the glycemic index.

There are two glycemic indexes because one is based upon sucrose and another upon glucose. In the sucrose based measurement, you can have a substance that has a glycemic index above 100 (which means that the substance affects your blood glucose more than sucrose). No substance has a glycemic index above 100 based upon the glucose scale.

This reveals why the glycemic index is not used in official measurements. If I give a dozen labs a box of Cap’n Crunch and asked them to tell me the number of calories, sugars, starches, fiber, vitamins, etc., they’d pretty much all agree. If I asked them to find the glycemic index, they’d all come up with different measurements. Also, why the labs could give me the basic nutritional information in a matter of days, the glycemic index measurements will take a few weeks. And, be quite expensive.

The glycemic index depends upon the subjects used, the lab, the protocol, and many other variables. It is lengthy and takes a long time to work out. This is why you will not ever see any governmental body requiring the glycemic index on food.

This isn’t to say that the glycemic index is useless. The glycemic index does show that many starches are actually more digestible than plain sucrose, and that by saying that eating something that is “low in sugar”, but is composed of highly processed starches isn’t necessarily better for you.

The glycemic index shows us that eating something with oil and protein can slow down the breakdown of starch, and that less unprocessed carbohydrates tend to have a lower glycemic index. And, how something is cooked can have a dramatic impact on the glycemic index. Overcooking pasta can double its glycemic index. Boiling potatoes and mashing them gives an extremely high glycemic index. Mixing them with milk and butter lowers it. Roasting the potatoes (that is putting it in the over without foil) also lowers the glycemic index.

Most important of all, the glycemic index has shown that the difference between starches and sugars are not all that different. If your cereal contains whole grain flour and a lot of fiber, the starch in it is probably not like sugar. For example, Raisin Bran would not be 43 grams of sugar. However, if you were eating something made from processed oat flour or corn flour that contains little fiber, that starch is pretty close to being nothing more than sugar.

I have never once seen a cereal label that separates out starch and I can’t find an example through an image search. Every American nutrition label in my experience has an overall number of carbohydrates, with partial breakouts of other certain types. Sugar always means sucrose on an ingredients or nutrition labels. Other carbohydrates may be other simple sugars, or
disaccharides, or polysaccharides, or oligosaccharrides, or fiber, or starches, or whatever might be in there besides sucrose.

Simple sugars can be absorbed from the intestines into the body directly. All other carbohydrates must be broken down (which is what digesting usually means as a definition) into simple sugar components or else they are not absorbed. So starches cannot be digested as quickly as simple sugars.

Nope, on the nutritional labels, sugar means all mono and disaccharides. That includes fructose, sucrose, dextrose, and glucose. Starches are long complex hydrocarbon chains that maybe made from sugars.

As it stated in the regulations 21 CFR 101.9©(6):

All carbohydrates must be turned into glucose to be used in the body for energy. That includes simple sugars like sucrose. Certain starches like potato starches can actually break down and be turned into glucose faster than sucrose. That’s why potatoes can have a glycemic index (based upon sucrose) of over 100.

Surely not, otherwise anything purely sweetened with HFCS would be listed as 0 sugar.

You’re right. I was thinking of ingredients lists.

Sucrose is not a simple sugar. It’s the disaccharide of glucose and fructose.

And while it is true that all simple sugars are converted to glucose for use, that does not take place in the process of digestion but elsewhere. Fructose is converted to glucose by the liver. Same with galactose.

Of course, this whole discussion starts depending on your definition of digestion and what it comprises.

Nope, they need to be made into monosaccharides before being broken up to fuel ATP prodution, but not all monosaccharides are converted to glucose. Fructose for example skips the first few steps of glycolysis, while sedoheptulose contains too many carbons (7) to easily convert to glucose and ribose contains too few (5).