The potato fear that won’t die

You’ve cut the bread. You’ve cut back on pasta. And somewhere along the way, someone told you potatoes were next.

If your blood sugar is “borderline,” or you crash at 3pm, the advice to avoid potatoes is everywhere. And there’s a reason for it. Potato starch digests fast, and a plain boiled potato can send your blood sugar up quickly. But that’s only half the story.

The other half is that potatoes and blood sugar have a much more flexible relationship than the headlines suggest. How you cook a potato, how long it cools, what you put on it and what sits next to it on the plate all change how your body handles it. I’ll walk you through the science, then give you my go-to way to grill them: charred red potato wedges with lemon, dill and parsley.

What actually happens to your blood sugar when you eat potatoes

A freshly boiled potato eaten on its own is a fast carbohydrate. In a small study of 13 healthy adults, freshly boiled potatoes raised blood sugar and insulin more than the same amount of carbohydrate from white bread.¹

That’s the snapshot behind the fear. A quick rise, then often a drop, and that drop is what many women feel as the afternoon crash or the sweet craving that follows.

But notice what that snapshot is. It’s a hot potato, by itself, with nothing around it. That isn’t how most of us eat, and it’s not how I’d ever suggest you do.

The resistant starch trick: let them cool

Here’s the part most people have never heard. When you cook a potato and let it cool, some of its starch changes form. It becomes resistant starch, which your body digests more slowly.

That same study tested this. The researchers stored cooked potatoes in the fridge for 24 hours, and the resistant starch went from 3.3% to 5.2%. The insulin response was 28% lower than with freshly boiled potatoes.¹

I like this one because it’s so ordinary. You don’t need a special potato or a supplement. You need a fridge and a little planning.

There’s one honest limit. That study measured potatoes eaten cold. I can’t promise a reheated potato gives the same result, so I wouldn’t count on it. That’s why I like the leftovers of this recipe at room temperature or straight from the fridge the next day, as a potato salad with no mayonnaise.

How to build a potato side that won’t spike you

Three things change the picture: acid, what’s next to the potato, and how much you eat.

Add acid.In the cold-potato study, cold potatoes with a vinegar dressing gave a blood sugar response 43% lower and an insulin response 31% lower than freshly boiled potatoes.¹ A second small study gave mashed potatoes to 16 people with type 2 diabetes, with and without vinegar. Their blood sugar rise was about 42% lower with it.² Earlier research suggests the reason: acid probably slows how quickly a starchy meal leaves the stomach.³

Those studies used vinegar, not lemon. Lemon juice is acidic too, so the idea carries over, but I can’t promise you the same numbers. That’s why this recipe uses the juice of a whole lemon.

Put protein and fat beside them. A bowl of potatoes alone is a starch meal. Add grilled chicken, fish or eggs, and a spoonful of tahini sauce or green goddess dressing, and it becomes a meal that holds you for hours. Anchor it with protein.

Keep the portion sensible. In this recipe, one serving is about 2/3 to 1 cup, or six wedges.

If you take medication for blood sugar, check with your healthcare provider before you change how you eat.

My go-to grilled potatoes with lemon and dill

Red potato wedges get charred on the grill until they’re crisp at the edges and tender in the middle. Then they’re tossed with lemon, dill, parsley and red onion while still warm. It’s seven ingredients, and you grill most of it hands-off.

Ingredients

• 4 medium red potatoes, cut into wedges
• 2 tbsp extra virgin olive oil, divided
• Sea salt and black pepper, to taste
• 1 lemon, juiced
• 2 tbsp fresh dill, chopped
• 2 tbsp parsley, chopped
• 1/4 cup red onion, sliced

Directions

1. Preheat the grill to medium-low heat. In a bowl, toss together the potato wedges, half of the oil, salt and pepper.
2. Grill the potatoes for 10 to 12 minutes on each side, or until they are charred and fork-tender.
3. Meanwhile, in a bowl, mix together the remaining oil, lemon juice, dill, parsley and red onion. Once the potatoes are cooked, transfer them to a plate and let them cool for about five minutes.
4. Add the potatoes to the bowl and toss to combine. Adjust the seasoning to your taste and enjoy.

Notes

• Serving size: One serving is about 2/3 to 1 cup, or six wedges.
• Serve it with: Tahini sauce or green goddess dressing.
• Extra toppings: Feta or parmesan cheese.
• Leftovers: Refrigerate in an airtight container for up to three days. They’re good cold the next day (see the resistant starch section above).

So, are potatoes bad for your blood sugar?

Not on their own, and not when you treat them well. Cool them when you can. Add acid. Put protein and a little fat beside them. Keep the portion sensible. You don’t have to give up a food you love. You need to understand what your body does with it.

That’s the work I do in Body Balance, my 5-week program for midlife women. We look at what your own body needs, so you can stop guessing about the crash, the cravings and the 3am wake-ups. No overhaul of your whole life required.

If this sounds familiar, let’s talk. Book a Meet & Greet and we’ll see where to start.

Warmly, Anna

References:

1. Leeman M, Östman E, Björck I. Vinegar dressing and cold storage of potatoes lowers postprandial glycaemic and insulinaemic responses in healthy subjects. European Journal of Clinical Nutrition, 2005. In 13 healthy adults, cold-stored potatoes and a vinegar dressing lowered blood sugar and insulin responses compared with freshly boiled potatoes. Read the study
2. Liatis S, Grammatikou S, Poulia KA, et al. Vinegar reduces postprandial hyperglycaemia in patients with type II diabetes when added to a high, but not to a low, glycaemic index meal. European Journal of Clinical Nutrition, 2010. In 16 people with type 2 diabetes, vinegar lowered the blood sugar response to mashed potatoes but not to whole grain bread. Read the study
3. Liljeberg H, Björck I.Delayed gastric emptying rate may explain improved glycaemia in healthy subjects to a starchy meal with added vinegar. European Journal of Clinical Nutrition, 1998. In 10 healthy adults, vinegar added to white bread lowered blood sugar and insulin responses, probably by slowing how fast the stomach empties. Read the study