"Women can tell you how many degrees (Fahrenheit and Celsius, to say nothing of Kelvin) it was outside." -Optimistic. on first kisses
Question #30243 posted on 11/07/2006 3:01 a.m.

Dear 100 Hour Board,

Thanks for your suggestions on my earlier question. I think I just need to get more sleep, as Optimistic suggested.

Reading over my earlier question made me think of something, though: Do carbs really make you feel sleepy, while protein helps you feel more awake? My mom has told me this for the longest time, but I think it might be an old wives' tale.


- Probably Not a Narcoleptic

A: Dear Hopefully Not a Narcoleptic ~

Well, I don't know about carbs making you sleepy—in fact, I think that might be a wives tale as I will dispute later—but I will stand up for proteins making you feel more awake. At least in some instances.

So one day, I went to donate blood. They turned me away! I couldn't believe it. Apparently, my hematocrit levels were too low. (For those of you who don't know what hematocrit is (I didn't) here is a definition from MedlinePlus Medical Encyclopedia: "The hematocrit is the percent of whole blood that is composed of red blood cells. The hematocrit is a measure of both the number of red blood cells and the size of red blood cells.") Then she (the Red Cross lady who told me I couldn't donate blood) shocked me: "Have you been feeling extraordinarily tired lately? Without a good reason?" Just the day before I had been walking around in a daze because I was really tired. I had no reason to be tired. I had gotten plenty of sleep the night before. Nevertheless, I was incredibly tired. So when she asked me if I had been extra tired without a cause, I was floored. So I told her I had and asked why. Apparently, low hematocrit levels can indicate low iron—anemia. (It can also indicate other things, but I'm not going to get into those. For more info, see the above linked webpage.) According to Familydoctor.org the symptoms of anemia are (emphasis added):

- Often, no symptoms
- Paleness
- feeling tired
- Unusal shortness of breath during exercise
- Fast heartbeat
- Cold hands and feet
- Brittle nails
- Headaches

She told me that being overly-tired, especially without a reason, is usually a very good indicator of low hematocrit levels. Huh. Who knew?

The three main causes for low hematocrit levels are 1) Genetics 2) Blood loss 3) Diet. So she gave me a list of good foods, high in iron, to help raise the hematocrit levels in my blood. That list, as well as a lot of internet research on anemia, low iron, and low hematocrit, showed that certain foods high in iron will help prevent anemia:

- liver and other meats (the nice lady at the Red Cross told me that liver is the best source of iron, but she wouldn't recommend it because it is gross. Haha.)
- Seafood
- Dried fruits like apricots, prunes and raisins
- Nuts
- Beans, especially lima beans
- Grean leafy vegetables, such as spinach and broccoli
- Blackstrap molasses
- Whole grains
- Iron-fortified breads and cereals (check the label)

Now, that is not a complete list. There are many other foods out there with iron in them. However, that is a good list to get started.

As we can see, proteins (i.e. meat and nuts) are on the list of foods high in iron. Hence, at least in the case of anemia, they will combat sleepiness. However, it also lists whole grains. And whole grains are full of carbs. So carbs should wake you up, too. So let's research this whole iron diet a little more, shall we?

According to Jackson Siegelbaum Gastroenterology there are two types of iron: heme and nonheme. "Heme iron is found in meats, poultry, and fish. Nonheme iron is found in both plant and animal foods.
Heme iron is more easily absorbed by the body than nonheme iron. However, heme iron can also promote the absorption of non-heme iron. Therefore, eating beef and beans, for example, is good for providing adequate absorption of both types of iron." However, it also states that: "Phytic and tannic acids are two food components that, when consumed in large amounts, prevent the absorption of iron. Phytic acid is found in rye bread and other foods made from whole grains. Phytic acid is also found in nonherbal teas. Tannic acid is found in commercial black and pekoe teas, coffee, cola drinks, chocolate, and red wines." So first, yay for the Word of Wisdom! Second, we can see that many foods made from whole grains can actually prevent the absorption of iron, not making us sleepy, but preventing us from combatting the sleepiness. On a side note, "Vitamin C also promotes iron absorption. This is true for both heme and nonheme iron. It is, therefore, beneficial to consume citrus fruits or juices, which are high in vitamin C, with foods that contain iron. For example, a meal might include a lean sirloin steak (heme iron source), baked potato (nonheme iron source), broccoli (nonheme iron source), and an orange (vitamin C source) for a good iron intake."

So, although my answer doesn't specifically answer your question as pertaining to carbs vs. proteins in general, here is a case in point example of how proteins can help keep you awake and how carbs can make you feel tired.

Oh, and before I forget—my main reason for not fully believing that carbs make you sleep is due to the fact that I eat a bowl of Honey Bunches of Oats with Almonds every morning because it has 45% Daily Value of Iron in it. It also has 25g of carbs (8%). I have found that the days that I start my day high in iron, I am much more likely to not be tired all day. A bowl of cereal that boasts being a "good source of Whole Grain" doesn't seem to hinder the iron factor. I suppose it's simply "moderation in all things," really. If you were to eat only carbs all day, you'd probably be tired. If you were to only eat meat all day... well, I'm not going to get into that. That's a whole other topic completely. It's about finding that happy medium.

~ Dragon Lady