By: Jenny Heap, MS, RDN
As nutrition professionals, we understand that starchy vegetables – including potatoes – can be perplexing for patients and clients with diabetes. We’ve all heard the questions: Shouldn’t I avoid starchy vegetables? Is it true that potatoes are no better than white bread? Armed with the facts and a few responsible preparation tips, potato enthusiasts with diabetes can enjoy the nutritional benefits of a favorite comfort food with ease.
Star Nutrients for Diabetes Management:
Before discussing how to include potatoes, we should first address the “why.” When appropriate preparation methods are used, potatoes are a smart, nourishing addition to diabetes-friendly diets.
Did you know that potatoes are a significant source of several star nutrients for diabetes management? One medium skin-on potato delivers:
Vitamin C: 20mg, 30% of the daily value.
Vitamin C is a topic of rising interest for diabetes researchers. Studies show that diabetes increases vitamin C requirements and that higher intakes might help improve both blood pressure and glycemic control.1 A recent analysis of EPIC–Norfolk and NHANES datasets demonstrated that participants with type-2 diabetes (T2D) required a higher intake of vitamin C to reach adequate circulating levels than those without diabetes. This indicates that the disease process increases vitamin C usage, bumping vitamin C requirements to approximately 1.5x the standard requirements.2 Additional evidence suggests that oxidative stress might play a role in the development of T2D and that natural sources of vitamin C may be protective.3
Vitamin B6: 0.2mg, 10% of the daily value.
This B vitamin is known to play an important role in carbohydrate metabolism, but it doesn’t stop there. There is ample evidence to suggest that serum levels of vitamin B6 are inversely related to T2D and its progression.4
Magnesium: 46.7mg, 11% of the daily value
Potatoes are a significant source of magnesium in Americans’ diets, with an estimated 5% coming from potatoes.5 Magnesium helps regulate blood pressure and blood glucose levels.
Magnesium insufficiency is common in T2D and is thought to worsen insulin sensitivity.6 A new retrospective analysis of NHANES data (1999-2018) found that higher intakes of dietary fiber and magnesium were associated with reduced long-term risk of cardiovascular death and death from all causes in people with T2D.7
Dietary Fiber: 2g, 7% of the daily value
The fiber in potatoes helps slow digestion and absorption of carbohydrates, helping to blunt the glucose response. Fiber also enhances satiety, contributes to bowel regularity, and may have beneficial effects on the gut microbiome.
High-Quality Plant Protein: 3g
It’s well understood that protein is critical to blood sugar management. While potatoes aren’t high in protein, the biological value is surprising. Depending on the variety, the biological value of potato protein comes in between 90 and 100 – approaching that of an egg – and scores higher than protein from soybeans and legumes.8
Glycemic Index and Diabetes Management:
The glycemic index (GI) is a popular, research-backed food scoring system widely adopted by consumers. It attempts to predict the impact of individual foods on blood glucose levels. Though it appears to simplify food choices, the practical application of GI scores is limited as they cannot take into account the context of day-to-day eating occasions.
For example, though cooked potatoes are considered a high-GI food, the actual impact on serum glucose can vary significantly and depends on the method of preparation, portion size, macronutrient composition of other foods consumed at or near the same time (sometimes referred to as glycemic load), in addition to potato maturation, variety, and origin. The glycemic response to any given food can also vary widely between individuals.9 10 11 Selecting foods based solely on GI score discounts real-life variables that determine the glycemic impact of meals eaten outside of a controlled laboratory setting.
Mary Ellen Phipps, M.P.H., RDN, LD, is the author of The Easy Diabetes Cookbook and a contributing writer, recipe developer, and content expert for WebMD, CNBC, and other leading health and wellness news outlets. Having managed type 1 diabetes since she was five years old, she has a wealth of practical experience and shares this advice with clients managing diabetes:
“While paying attention to the glycemic index and choosing foods that are low on the glycemic index can play a positive role in blood sugar management, it’s also important to pay attention to the overall glycemic load of your meal. Adding additional protein and fiber sources to higher glycemic foods can reduce the overall glycemic load of the meal you’re enjoying…”
The role of resistant starch:
Potatoes contain amylose, a resistant starch that is not broken down by digestive enzymes and has a smaller impact on blood sugar levels. It functions somewhat like a soluble fiber, undergoing fermentation by gut microbes and producing beneficial short-chain fatty acids. Though the cooking process makes amylose more digestible, cooling potatoes after cooking returns some of the starch to its resistant state.
Phipps advises, “…try cooking your potatoes the day before you want to enjoy them. Raw potatoes contain something called resistant starch. Our bodies treat resistant starch similar to fiber… Which is a great thing for your blood sugar levels! When we cook potatoes, [much of] the resistant starch gets converted to more easily digestible starch which can increase the glycemic impact of the potatoes. However, the process of cooling [them] down, storing them in the refrigerator, and reheating them after several hours can re-capture some of that resistant starch, potentially decreasing the glycemic impact.”
Research bears this out. Studies show that cooling cooked potatoes overnight reduces the glycemic impact. While eating the potatoes cold results in the lowest glycemic response, a reheated potato will still have a lower GI score than the same potato freshly cooked and eaten hot.12
Just add vinegar?
Studies also suggest that simply adding vinegar to complex carbohydrate meals can also help blunt glycemic response. One study showed that adding a vinaigrette dressing (made of olive oil and white vinegar) to cooked potatoes reduced the post-meal glucose and insulin response.13 Another found that including 20g (two teaspoons) of white vinegar with a meal composed of complex carbohydrates reduced the glycemic impact by 20% (compared to placebo).14
Strategies for minimizing potatoes’ impact on glycemic response:
In summary, thoughtful preparation can turn a higher-carbohydrate meal into an opportunity to maximize flavor and nutrition while supporting healthy blood sugar. Share these tips and strategies with your potato-loving diabetic patients and clients:
- Be mindful of portions and preparation method: Enjoy smaller portions and let potato dishes share the limelight with non-starchy vegetables and lean When you’re craving something crispy, try prepping potatoes in the air fryer.
- Complement with healthy fats, fiber, and protein: Add olive oil, plain Greek yogurt, sliced avocado,
and/or other healthy fats and proteins to a baked or mashed potato to slow digestion and reduce the glycemic load. Leave the skin on for texture, color, and to maximize fiber.
- Try cooling cooked potatoes overnight: Reheat the next day or better yet, use cooled potatoes as part
of a cold dish to maximize resistant starch content.
- Add vinegar: Dress a cool potato salad with homemade vinaigrette to reduce the post-meal glucose
Try these techniques with this craveable Lower Carb, Gluten-Free Potato Salad developed by Mary Ellen Phipps, M.P.H., RDN, LD, author of The Easy Diabetes Cookbook. The dressing incorporates apple cider vinegar and includes equal parts mayo and plain Greek yogurt to maximize protein. Enjoy!
Explore more at eatwisconsinpotatoes.com.
Content produced in partnership with the Wisconsin Potato and Vegetable Growers Association. Wisconsin Potato and Vegetable Growers Association represents growers committed to good agriculture, food safety, nutrition, traceability and providing America with fresh, high-quality produce. Wisconsin-grown potatoes offer more than just great taste. Local and sustainably sourced, they’re packed with nutrition no matter the variety. Every one of our Wisconsin Healthy Grown® farms is certified by an independent oversight organization. They ensure our growers pass annual Wisconsin Healthy Grown® Potatoes and Vegetables whole-farm audits, and that all our packers and shippers maintain the highest sustainability standards.
Look for the Wisconsin Healthy Grown® certification.
1 Mason SA, Parker L, van der Pligt P, Wadley GD. Vitamin C supplementation for diabetes management: A comprehensive narrative review. Free Radic Biol Med. 2023 Jan;194:255-283. doi: 10.1016/j.freeradbiomed.2022.12.003. Epub 2022 Dec 14. PMID: 36526243.
2 Carr AC, Lunt H, Wareham NJ, Myint PK. Estimating Vitamin C Intake Requirements in Diabetes Mellitus: Analysis of NHANES 2017-2018 and EPIC-Norfolk Cohorts. Antioxidants (Basel). 2023 Oct 15;12(10):1863. doi: 10.3390/antiox12101863. PMID: 37891943; PMCID: PMC10604478.
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7 Wang F, Mao Y, Sun J, Yang J, Xiao L, Huang Q, Wei C, Gou Z, Zhang K. Models based on dietary nutrients predicting all-cause and cardiovascular mortality in people with diabetes. Sci Rep. 2025 Feb 7;15(1):4600. doi: 10.1038/s41598-025-88480-9. PMID: 39920222; PMCID: PMC11805981.
8 King JC, Slavin JL. White potatoes, human health, and dietary guidance. Adv Nutr. 2013;4(3):393S-401S. Published 2013 May 1. doi:10.3945/an.112.003525
9 Fernandes G, Velangi A, Wolever TMS. Glycemic index of potatoes commonly consumed in North America. J Am Diet Assoc. 2005;105:557-562.
10 Henry CJ, Lightowler HJ, Strik CM, Storey M. Glycaemic index values for commercially available potatoes in Great Britain. Br J Nutr. 2005 Dec;94(6):917-21.
11 Mattan NR, Ausman LM, Meng H, et al. Estimating the reliability of glycemic index values and potential sources of methodological and biological variability. Am J Clin Nutr. 2016;104:1004-1013.
12 Leeman M, Ostman E, Björck I. Vinegar dressing and cold storage of potatoes lowers postprandial glycaemic and insulinaemic responses in healthy subjects. Eur J Clin Nutr. 2005 Nov;59(11):1266-71. doi: 10.1038/sj.ejcn.1602238. PMID: 16034360.
13 Leeman M, Ostman E, Björck I. Vinegar dressing and cold storage of potatoes lowers postprandial glycaemic and insulinaemic responses in healthy subjects. Eur J Clin Nutr. 2005 Nov;59(11):1266-71. doi: 10.1038/sj.ejcn.1602238. PMID: 16034360.
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