Thursday, July 11, 2013

N=2: Potatoes and Bananas

When Chad and I went low carb for real last September, we stopped eating potatoes and bananas.  Which was a little bit of a shock, considering I ate at least one banana a day, and we ate potatoes at least a few times a week.  Suddenly I had to fill that missing hole where potatoes and bananas used to be.

It wasn't too hard to do, though.  Mostly I just had to adjust and figure out other foods we could eat instead.  We eat a lot of berries now and some other seasonal fruit, and lots of frozen veggies with butter and salt in place of the potatoes. 

Being the curious person I am, though, I decided I really wanted to see what these starchy foods did to our blood sugar if we were to eat them again.  I know from experience that I've become more insulin sensitive the longer I've been low carb.  It seems like hardly anything makes my blood sugar go over 100 these days, unless I'm really trying to make it.  I even ate a small bowl of regular ice cream once to see what would happen, and my blood sugar stayed in the 90s. 

Since Chad had a four day weekend, we decided that would be a good day to do some experiments.  We ended up testing at one and two hours after eating. 

Here's what happened.


4:06 PM:
Julie: 95
Chad: 95

5:08 PM:
Julie: 91
Chad: 124

6:05 PM:
Julie: 92
Chad: 106

So it seems that Chad is much more sensitive to bananas than I am.  To be fair, his was a little bit bigger than mine, but that's how we eat anyway; he always eats about 1/3 more than I do at meals.

The next day, we decided to test potatoes.  We were a little more scientific with this one.  We measured the potatoes, and I made sure we both used the same amount of butter and sour cream, though Chad was welcome to use as much salt as he wanted. 

Chad's potato: 240g
Julie's potato: 215g

5:33 PM:
Julie: 87
Chad: 86

6:45 PM:
Julie: 130
Chad: 153

7:45 PM:
Julie: 107
Chad: 110

As you can see, we both got a pretty big spike there.  I made sure to keep track of my hunger levels, as well; at 6:45, I was pretty hungry, and by 7:45, I was feeling starved.  Chad said that by 7:45, he felt "not as full". 

I think what I can conclude from this is that neither of us should be eating huge potatoes for dinner (and they were quite large, by the way).  Maybe a small serving of potatoes with lots of fat and protein would be better, but not as an everyday thing.  Chad needs to stay away from bananas, but it seems like it's something I can handle.  I still think I'll only eat bananas as treats, though, and not as an everyday food.

I think next we need to test sweet potatoes, because we do eat those once in a while.


  1. I can see why you are testing but I'm not sure it is a true test unless you eat in the context of a meal. If I eat a starchy carb on its own I get a much bigger spike than when with a meal. I am like Chad - my blood spikes much more than my partner on foods like this.

    If I ever have potato, I keep it to a small piece... same with rice. I did a blood test the other night after a homemade curry and rice meal and my blood was great! I do think it has improved over time which is great. I think it is great to check though and be aware of what these food can do.

  2. And here I was considering re-introducing bananas into my diet for the potassium--maybe I'll just do one per week, or something, instead of daily.

  3. There are going to be healthy foods that cause some spike, sure. Bananas one of them. I go in spurts (thanks to them coming in a bunch, and I don't want to be 'the one' who separates them out)...I'll have one a day for a few days, then not again for a few weeks. But they are SO nutritious, I do believe, in limited quantities, they are healthy.

    We might have to agree to disagree on bananas. :)

  4. Everyone is an individual. That's why everyone should test their own blood glucose levels :) And as for bananas and their nutrients (especially potassium), I feel like I can get what they offer in a less carby form. For instance, Swiss chard and avacados have more potassium than bananas do.

    I'm not against bananas or potatoes, I just think they're foods that should be eaten in moderation.