For decades, grains like rice, wheat, and maize have formed the backbone of diets worldwide. But many people also lean on potatoes and other starchy vegetables as affordable and filling alternatives. Could you simply swap one for the other and maintain the same nutritional benefits? While many weight loss diets and crash diets may suggest this, a new analysis published in 2025 in the journal Frontiers in Nutrition argues, not quite. The researchers used data from the US Dietary Guidelines modelling framework and mapped how dietary nutrient intake changes if grains are replaced by potatoes or other starchy vegetables. The result shows that while potatoes offer some nutritional advantages, they lack several vital nutrients present in grains.
That means relying heavily on potatoes, or eliminating grains, may leave gaps in essential nutrients like iron, folate, zinc and certain B vitamins. In short, potatoes are healthy, but they cannot substitute all the nutrition that grains provide. Here's a breakdown of why both food groups belong on your plate.
What The Study Found: Potatoes Vs Grains, Different Nutrient Packages
Potatoes Bring Their Own Strengths
According to the study, a typical recommended serving of white potatoes contributes: about 11% of daily potassium requirements, 10% of vitamin B6, and smaller but significant amounts of fiber, magnesium, vitamin C, thiamin and niacin, all while adding only 5% of daily calories. (Frontiers)
Potassium, vital for heart, nerves and blood pressure, is especially high in potatoes, far more than what's offered by whole or refined grains. Vitamin C and micronutrients like magnesium and niacin are also useful perks, often missing in grain-heavy diets. Thus, potatoes effectively help fill nutrient gaps common in modern meals.
But Grains Offer What Potatoes Don't
On the flip side, grains - especially whole grains - supply higher levels of iron, folate, calcium, zinc, selenium, riboflavin, and a broader range of B-vitamins compared with potatoes. In the study's diet-modelling scenarios, replacing refined or whole grains with starchy vegetables consistently caused the levels of these micronutrients to fall, meaning a diet heavy on potatoes but light on grains could risk deficiencies.
Fibre is another big difference. Whole grains generally provide more dietary fibre than potatoes, aiding digestion and helping maintain stable blood sugar, benefits essential for metabolic and gut health.
Why Potatoes And Grains Aren't Interchangeable: The Science Explained
- Nutrient diversity matters: Every food has a distinct "nutrient package." While potatoes are rich in potassium and vitamin C, grains are richer in iron, B-vitamins and trace minerals. Swapping one for the other repeatedly means losing what the other provides.
- Different roles in diet patterns: Potatoes, starchy vegetables, contribute to vegetable intake, supporting recommendations for vegetable diversity. Grains, on the other hand, offer dense calorie-plus-nutrient yield, especially useful for energy, brain function and red blood cell production (via iron, B-vitamins, folate).
- Risk of micronutrient shortfall: The study's modelling shows that dropping grains could reduce intakes of nutrients critical for long-term health, potentially increasing risk of anaemia (iron/folate deficiency), weakened immunity (zinc), metabolic stress (B vitamins), and digestive issues (lower fibre).
What This Means For You: Smart Ways To Build A Balanced Diet
- Mix, Don't Swap: Instead of replacing grains with potatoes, or vice versa, aim to include both in your eating plan. Use whole grains (brown rice, millet, whole wheat) for meals needing sustained energy and micronutrients, and add potatoes or other starchy vegetables as side dishes, this ensures you tap benefits from both food groups.
- Diversify Food Sources: Don't rely only on grains and potatoes. Also include legumes, pulses, vegetables, leafy greens, fruits, nuts and dairy or other calcium sources. This variety will help cover the micronutrient gaps that a grain-or-potato diet leaves.
- Watch Cooking Methods: How you cook potatoes, and grains, matters. Baking, boiling or steaming potatoes preserves nutrients. Avoid frequent deep-fried potato preparations (like fries or chips), which add excess fat and calories and can worsen metabolic risks. This aligns with broader nutritional advice to prioritise whole, minimally processed foods.
- Balance Portion And Frequency: Use potatoes and starchy vegetables to add variety, but avoid over-relying on them as sole staple. Maintain recommended servings of whole grains (or fortified/refined grains, where appropriate), and combine both with adequate protein and fresh produce.
The 2025 study makes one thing clear. Potatoes and grains bring different, complementary nutrients to the table. Potatoes deliver potassium, vitamin C, some B-vitamins and fibre; grains offer iron, folate, a broad B-vitamin set, trace minerals and higher fibre (especially whole grains). Swapping grains for potatoes may seem convenient especially for weight loss diets, but over time it will lead to nutrient gaps. The healthier approach? A balanced plate which includes whole grains, occasional potatoes or starchy vegetables, ample vegetables, pulses or legumes, and a variety of protein and mineral-rich foods.
Disclaimer: This content including advice provides generic information only. It is in no way a substitute for a qualified medical opinion. Always consult a specialist or your own doctor for more information. NDTV does not claim responsibility for this information.
