Obese children and low-carb diets

I thought this story was interesting enough to share, Obese kids have hard time sticking to low-carb diet:

“For the new study, researchers randomly assigned 100 obese 7- to 12-year-olds to one of three eating plans: one that followed the conventional wisdom of portion control; a low-carb diet; or a reduced glycemic load plan that cut down on certain carbs that typically cause surges in blood sugar…

“Over one year, all three plans worked equally well in controlling kids’ weight gain. The difference, researchers found, was that the low-carb plan was tough to stick with.

“…kids in all three diet groups ended up with healthier cholesterol levels.”

Thanks, Chris!

11 Responses to “Obese children and low-carb diets”

  1. Sugarlake Says:

    “…especially highly refined or starchy carbs like white bread and potatoes.”

    Why is every food that’s made of potato a “potato” to most people. It’s really not the potato that makes people fat. It’s the fat they put on it that makes them fat.

    French fries, chips, potato with sour cream are not high in carbs they are high in fat.

  2. Jack Norris RD Says:


    It’s a good point – kind of like how people consider meat to be “protein”. However, white potatoes are somewhat unusual in how fast their starch is broken down into glucose and one study found that in obese people, white potatoes increased the risk of type 2 diabetes independently of any food they were combined with:


  3. Sugarlake Says:

    Wow, i didn’t know that. So are only obese people under an increased risk? Because i eat a lot of potatoes but i’m not obese. Maybe i shouldn’t eat that many.

  4. Jack Norris RD Says:


    Yes, in the study linked to below (which is the only one I know of that has carefully studied white potatoes over the long term), only people with a BMI above 30 (which is classified as “obese”) had an increased risk of type 2 diabetes from higher amounts of potatoes (though french fry intake was associated with an increased the risk for both those with a BMI below and above 30).

    I think what it probably comes down to is that if you are not eating enough calories to gain weight, then potatoes are not going to harm you.

  5. SpeciesistVegan Says:

    What’s the takeaway here? That low-carb is bad? Or that low-carb is bad, and by extension, meat/non-vegan food is bad?

    I for one think that consciously eating low- or moderate-carb is good, especially for vegans and vegetarians, who tend to overconsume carbs (to the relative exclusion of nutritious, high-fat/protein foods like nuts and seeds). There is no reason that a low- or moderate-carb diet has to be incompatible with being veg*an.

    Sorry, maybe I just miss what the point of this post is. Maybe you can clarify?

    As for potatoes – people with a BMI over 30 almost for sure have insulin resistance, hence the exaggerated reaction to potatoes. And it’s curious that potatoes get a bad rap with people who probably eat brown rice because equal amounts of each have very comparable glycemic loads. So what gives?

  6. Jack Norris RD Says:


    > What’s the takeaway here? That low-carb is bad?

    There was no takeaway message (as far as I was concerned), I just thought it was interesting both that the kids had a harder time on the low-carb diet and that the low-carb diet improved cholesterol levels. Both findings were a bit counter intuitive. Would you have preferred I didn’t post it? (Serious question, I don’t want to waste readers’ time.)

    As for potatoes and glycemic issues, I think you are correct that the insulin resistance is key to why obese people have more issues with them. I also didn’t realize that white potatoes and brown rice had a similar glycemic load. However, you might find this interesting regarding the insulin index (which might be more important than either the glycemic index or glycemic load):


    If you go to p. 6 you will see that based on a score of 100% for white bread, the insulin score for brown rice is 62%. Potatoes are the only whole plant food that scores higher than white bread with a score of 121%. Interestingly, white pasta only scores 40.

    I should add that I do not, by any means, consider myself an insulin index expert and if someone who knows more about it makes a persuasive argument that insulin index is not as important as glycemic load, I’d be inclined to trust them. 🙂

    The takeaway message here is that potatoes, and presumably white potatoes, do have a unique quality when it comes to blood sugar and insulin. Nonetheless, I ate some today and do not think they are a deadly poison for most people.

  7. Ariann Says:

    I have a BMI over 30 (gained a ton of weight while pregnant and working to lose it) and had an oral glucose tolerance test during my third trimester and my blood glucose levels were very low at the one hour mark (in the 60s). So I assume that means I don’t have insulin resistance. So what does that mean for me and potatoes?

  8. Jack Norris RD Says:


    Since gaining and losing weight is a normal part of pregnancy and your blood sugar seems quite good, I doubt they will cause you any harm. That said, given potatoes large insulin index, it might be easier to lose weight by minimizing them.

  9. Jack Norris RD Says:


    I should add that if you do not stabilize at a BMI below 30, then you might want to be more cautious because the study looked at BMI, not at insulin resistance. So, while the insulin resistance theory is probably a good explanation, it is only theoretical whereas the hard(er) evidence is with the BMI greater than 30.

  10. SpeciesistVegan Says:

    > Both findings were a bit counter intuitive.

    > Would you have preferred I didn’t post it?

    No, not at all. Sorry if I came off as dismissive. I just wasn’t sure if there was an implicit point I was missing.

    > However, you might find this interesting regarding the insulin index (which might be more important than either the glycemic index or glycemic load):

    Yes, I definitely find that interesting. Thanks for that. It’s something I’ve wondered about. Glycemic index is probably more important if you’re diabetic, but insulin index seems like it’s probably more important and useful to non-diabetics and people (like me) that have an interest in eating low(er)-carb. I will definitely be reading that paper.

    > Nonetheless, I ate some today and do not think they are a deadly poison for most people.

    Same here. But when I do eat them, I make sure to eat plenty of fat and protein along with them to blunt the insulin response. But now that I’m reading this paper, I’m wondering if that is actually not the right way to go. Thanks for the link.

  11. SpeciesistVegan Says:

    Thanks again for the link to that study. It was really interesting.

    I’m a bit disappointed that they decided to serve the lentils in tomato sauce, as tomatoes do contain carbohydrate (and so do the onions in the sauce – AND the olive oil is also insulinogenic). And then they didn’t test the tomato sauce alone, so it makes it hard to tease out exactly what was causing the insulin response. I guess they thought that the lentils wouldn’t be palatable without sauce. Same with the baked beans (for which they didn’t provide a key piece of info – did they contain sugar like most canned baked beans do?). So, basically, with all these variables, I still don’t really know what the insulin index of beans and lentils is, and that would be pretty good info for vegans and vegetarians to know!

    I also like that peanuts have the lowest insulin index, but I’m a bit disappointed that they didn’t test other nuts and seeds. Peanuts are very low carb, basically the lowest of the nut and seed group (I’m aware that it’s actually a legume, but you know what I mean). I would like to know how other nuts fare. Flax has essentially no carbs, so I’d be curious to see how it stacks up.

    I’m also pretty surprised that pasta has such a small insulin response. This confirms the anecdotal evidence I already had (my sister had gestational diabetes, and ate a good amount of pasta to help keep her glucose levels down – seemed counter-intuitive to me at the time!). It actually makes me rethink pasta.

    And like they said, it remains to be seen if any of this really “works” “in a mixed-meal context.” Most people don’t sit down and nosh 239 kcal of dry potatoes.

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