June 1, 2008

You Ask, I Answer: Potatoes/Walter Willett's Healthy Eating Pyramid

I don't really know anything about the science of nutrition, so I won't state an opinion either way on the potato issue. But have you read Willett's book, Eat, Drink, and Be Healthy?

I think the pyramid is misleading by placing potatoes up there without an asterisk or something, but he does go into detail in Eat, Drink and Be Healthy about studies showing that potatoes cause a spike in blood sugar in the same way that refined grains do.

Again, not a scientist so I can't evaluate the merit of the studies and whatnot, but I'd suggest you check it out so you can decide if you agree.


Personally, I like potatoes a lot...but I mostly like them in less healthy ways (not crazy about the skin, like them mashed, etc), so I try to limit them.


Working at Harvard School of Public Health as I do, it's easy to feel a bit oppressed by the pervasiveness of Willett and the Healthy Eating Pyramid, though!


-- Daphne (last name unknown)

Via the blog

Your question brings up several issues worth mentioning (by the way, I realize you are not in favor of the "potatoes are just as bad as sugar" argument, so this is not a "response" to you).

I agree with Dr. Willett on many nutrition standpoints, but the potato issue is one I see completely differently.

I have not read Eat, Drink, and Be Healthy, but am familiar with his reasoning for placing potatoes at the top of his Healthy Eating Pyramid along with white flour, sugar, and candy.

Willett bases that decision on potatoes' high glycemic index (basically, the degree to which they raise your blood sugar upon consumption).

The problem with that reasoning is that it only truly applies if a potato is eaten entirely by itself.

Have it as a side dish to a high-protein food (salmon, chicken, tempeh, etc.), top it with a little fat, and the glycemic index decreases.

Since a potato's skin is a good source of fiber, eating it helps lower the glycemic index.

As I have mentioned before, a potato is not a potato is not a potato.

Dehydrated potato flakes from a box that turn into instant mashed potatoes are very different from French fries, which are very different to a baked potato cooked in its skin, topped with olive oil, and eaten in conjuction with grilled salmon.

Besides, the glycemic index is not a very accurate way to determine what foods are healthy.

If you go by it, ice cream is a "better" snack than watermelon.

While it is helpful for people living with diabetes, I don't see it as the most useful tool for weight loss -- it leaves calories out of the equation!

If you were looking to cut calories, would you have half a cup of ice cream as a post-dinner snack or a cup of watermelon?

1 comment:

Anonymous said...

Thanks for the response, Andy - I appreciate you simplifying it a bit for me! Willett's book, though allegedly intended for the layperson, is a bit thick on the scientific details (especially chemistry, etc) for a person with no background in these subjects, so it's good to hear another side of the argument.