What does “glycemic” mean, anyway?

What does “glycemic” mean, anyway?

“Glycemic” is a word that gets tossed around a lot these days. It’s important to eat “low on the glycemic index,” or a healthy “low-glycemic diet.” But what does “glycemic” mean, exactly?


Glycemic: It’s all about sugar

The concept is actually pretty straightforward: The glycemic index measures how quickly different foods dump sugar into your bloodstream.

Here’s an example. Drink a cup of apple juice, and your body gets a speedy jolt of sugar. Eat a whole apple, though, and that doesn’t happen. What’s the difference? Fiber. It slows the whole process, keeping sugar delivery from the apple nice and slow. But without fiber, the apple juice gets an express pass into your bloodstream.

Glycemic index charts (like this one from Harvard) rank foods by their glycemic load—how much your blood sugar will actually rise after eating it. Apple juice packs five times the glycemic load of an apple.

Why does the glycemic index matter?

Blood sugar spikes aren’t healthy. They wreck your metabolism, forcing your liver to store the extra sugar as fat. They set off a dangerous chain reaction of insulin surges, high blood pressure, and high triglycerides, too. High-glycemic eating makes you more likely to get heart disease or several types of cancer.

Eat low-glycemic and you’ll soothe your insulin response, lose more weight—and keep it off, studies show.

So what should I eat?

It’s pretty simple. Low-glycemic-load foods tend to be whole, unprocessed foods—fresh fruits and veggies, whole grains, beans, and lentils—the only type of carbs you’ll find in The Fast Metabolism Diet. (You won’t find meats and fats on the glycemic index, because they don’t contain any sugar.)

Don’t get too wrapped up in the numbers, though. Watermelon has a high glycemic index (72 out of 100), but the amount of sugar in a serving of watermelon is so minuscule that it’s barely a blip in your blood sugar: it works out to a tiny glycemic load of 4. Sponge cake is technically lower-glycemic than a sweet potato, but obviously, the sweet potato is healthier.

Try these low-glycemic swaps:

Instead of this: Eat this:
Orange juice Orange
Instant oatmeal Steel-cut oats
White rice Brown rice
White potato Sweet potato
White bread Sprouted grain bread


Links included in this article will sometimes direct you to the ShopHayliePomroy.com website, where you can learn more about and purchase many of the products mentioned. Please know that Haylie Pomroy has a financial interest in anything that is sold from ShopHayliePomroy.com.

27 thoughts on “What does “glycemic” mean, anyway?

  1. Hi, I bought your book and am in week 1. Going well, haven’t seen much movement on the scale but I’m just aiming to loose 4% of my body weight, which is 7lbs, so I’m not worried about 20lbs. Anyway, I really need my coffee in the am, I can give up the sugar but must I give up the 1/2 and 1/2 for just one coffee a day in the am? I also wonder if small slips that are not in the phase I’m working on will kill the results. I think I ate one of my power balls in Phase 2 and they are made of nuts/prunes/whey protein… Could this be hampering my diet just because of small flubbs in my choices? I’ve been pretty much 90% on up to this point and haven’t even see .5lbs move… Up the exercise? I can add cardio 5 days a week but it doesn’t seem like that is an option… So many questions but I like what you have to say. Nice book. I would recommend.
    Lyons, CO

  2. Hi there, have lost 5.5 pounds in the 1st 2 weeks, slow but sure. Actually, in the middle of week 2 I had gained 1/2 pound, then by the end of the week lost 1.5 ! I am feeling better; there is no more “bloating” due to no dairy and wheat! Phase 2 is the most difficult not having the fruit, veggies not great for me in the morning, but suffer through the 2 days! Still have 25 pounds to lose, so will be on this program for a few months. I really like the book and the web site for support.

  3. I have been on for the 28 days. Only lost 8 lbs. I am going to stay with it for a while longer. Those days without the fruits are especially hard. I have cheated a few times but not terribly. I am happy for the 8 lbs and it was not that tough. Love almond butter on sprouted bread.

  4. I just started week 3, it’s been harder than I thought, but well worth it! I agree, p2 is the worst, I’m down 10lbs. Only 60 more tho go! The book is kinda confusing on some items, but all in all I’d recommend this diet for those who want tho eat healthy and not count calories!

  5. Dear Ms. Pomroy, many thanks for the continuous educational tips that you forward. Education re: nutrition is half the battle to empower us to make healthier choices not only for ourselves but our families.

  6. I found a recipe using radishes instead of Irish potatoes for potato salad and now I can’t find it again. Could you please tell me where it is? Thanks

  7. Hello Christine,
    Thank you for replying in the past. It was very helpful and I do really appreciate it.
    I have two questions; I am on a restricted diet but am able to and like to drink “tropical” drinks with puree of fruit and water, no sugar. I believe they are Dominican.
    Could you please see if you could tell me which phases the following fruits would be in? Guanabana, Zapote, Lulu, Horchata, Passion fruit or Maracuya, and Tamarindo?
    Also what phase would Yucca be in, it is a starcy vegetable?
    Thank you so much, Christine.

    • Hi there. There are no juices on the diet — and that includes water/sodas combined with fruit juices. You could certainly make your own type of drink in a blender using whole fruit (not juices) and using the fruits for the right phases. For instance, you could make something with pineapple or mango on Phase 1. Yucca isn’t on the food lists. It might be too starchy (this is why bananas are not on the diet as well).

  8. I am on week 2 Phase 1. I am so hoping this eating plan continues to work for me. I started on June 2 at 199lbs, and today June 9 I am 189. My husband is doing this plan with me, and he has lost 9 lbs. Caffeine is my hardest thing to give up (which I have),
    Where can I find the Stevia chewing gum.?.. I need gum more than caffeine.

    • Congratulations! Xyla brand gum works on the diet. Another B-Fresh, though I have not seen that one in as many stores. You can find both online.

  9. Read the article and i have a question.

    If I want to eat dates (high in sugar) for example, should I eat them with some fiber in order to get a lower Blood sugar spike vs eating it alone? if so, should i eat the fiber first? or it does not matter?

    • Dried fruit isn’t on the diet — but after the diet, if you wanted to eat dates, eating them along with a protein and veggies is one way to blunt the sugar effect.

  10. Haylie posted “why, when and how to ask for lab tests: Thyroid panel” and states that if the TSH levels are high one should go with higher glycemic fruits and grains. Which fruits and grains would that be?

  11. ,salve , ho avuto modo di acquistare il vostro libro ma malgrado apprezzi il contenuto di cui voi spiegate molto in fatto di svariati alimenti in particolar modo l’humus che ho difficolta’ a reperire nella mia zona (sud italia -puglia-) e se potresti darmi indicazioni in alternativa a questo alimento.
    poi vorrei chiedervi se si potrebbe sostituire con altri alimenti il salmone affumicato con cetrioli o roast beef di cui pasti abbastanza elaborati per un primo mattino per una persona che lavora alle prime ore dell’alba ed il posto e la mansione del lavoro non permettono di consumare tale pasto da voi programmato.
    saluti cinzia

    • Ciao. Hummus è un condimento mediorientale fatto di chicchi di purè di ceci, limone e pasta di sesamo. Potete fare il vostro proprio – è facile trovare una ricetta on-line.
      E sì – è possibile sostituire altri alimenti fase. Non è necessario utilizzare le ricette nel libro fino a quando i cibi sono sulle liste di cibo per quella fase.

  12. My husband and I are completing our 3rd week. We feel fantastic! My husband looks 10 years younger. My question is…I just completed phase 2..I woke up this morning feeling good, ate breakfast and I feel light headed and short of breath. Phase 2 tends to make me feel like this. I have followed this program “by the book”. I have not cheated at all. Any suggestions?????

  13. I have a question about sweet potatoes. They are listed as unlimited portions for phases one and three. Is it truly unlimited? It would be very easy for me to eat a very huge portion of these to help when I feel extra hungry but my past tells me that portions matter so it’s hard to get out of that mindset. I am pretty convinced that if I eat unlimited sweet potatoes I will definitely gain weight.

    • Yes, they are unlimited. But Haylie also says you should mix it up and eat a wide variety of vegetables. So eating all sweet potatoes would probably not be smart, just as eating all of any vegetable might not be the best idea. So use your common sense – a sweet potato per day is probably just fine.

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>