Are Potatoes Good for Weight Loss? What the Research Actually Shows

Potatoes are usually the first food people cut when they start a diet. They are starchy, they have a high glycemic index, and they are the base of fries and chips. Yet in one of the best-known studies of how filling foods are, plain boiled potatoes came first out of 38 foods, by a wide margin.

So are potatoes good or bad for weight loss? The research gives a clear answer, and it depends far more on how you cook and top them than on the potato itself. This guide covers the satiety evidence, the weight-loss trials, why big studies link potatoes to weight gain, and how to eat them while losing weight.

Quick Answer

Yes, potatoes can be good for weight loss when they are boiled, baked or steamed and not loaded with fat. Boiled potatoes were the most filling of 38 common foods per calorie, seven times more filling than a croissant. In weight-loss trials, people who ate potatoes 5 to 7 times a week lost weight as long as they cut calories, and a low-energy-density diet built around potatoes cut body weight by 5.6 percent in 8 weeks. The problem is the form: French fries and chips are linked to weight gain, type 2 diabetes and higher mortality, while baked, boiled or mashed potatoes were not linked to diabetes in a 2025 study of 205,107 people. Keep the skin on, watch the toppings, pair them with protein and vegetables, and cooling cooked potatoes can lower their blood sugar effect.

In this guide:

• Why Potatoes Are So Filling
• What Weight-Loss Trials Show
• Why Potatoes Have a Bad Reputation
• Fries vs Baked: The Form Is What Matters
• The Glycemic Index Question
• How to Eat Potatoes and Lose Weight
• The Verdict

Why Potatoes Are So Filling

Losing weight is easier when the food you eat keeps you full on fewer calories, and this is where plain potatoes stand out. In the classic satiety index study, people ate 240-calorie servings of 38 common foods and rated their fullness every 15 minutes for two hours, then could eat freely. Boiled potatoes scored highest of all, at 323 percent of white bread, seven times the score of the lowest food, a croissant.

The same study explains why. Foods were more filling when they had more water, fiber and protein and a larger serving for the same calories, and less filling when they had more fat. A plain boiled potato is mostly water and starch with some fiber, so 240 calories is a big, filling portion. Fry it or load it with butter and cheese, and the same calories shrink to a few bites. The satiety measure is the thread running through our guide to the best foods for weight loss.

What Weight-Loss Trials Show

Two randomized trials tested potatoes directly in people trying to lose weight:

• Potatoes every week, with fewer calories. In a 12-week trial, 90 adults with overweight were all told to eat 5 to 7 servings of potatoes a week. Two groups also cut 500 calories a day on either a low or high glycemic index diet; the third got no diet advice. All three groups lost a modest amount of weight and the differences between them were not significant. The researchers concluded that weight loss came from eating fewer calories and that potato intake did not cause weight gain.
• A potato-based diet in people with insulin resistance. In an 8-week controlled feeding trial, 36 adults with insulin resistance ate a low-energy-density diet built around either potatoes or beans. Body weight fell by 5.6 percent on the potato diet and 4.1 percent on the bean diet, with no significant difference between them, and insulin resistance improved on both.

Both trials point to the same principle: potatoes fit a weight-loss diet when the overall diet is lower in calories and the potatoes are not turned into a high-calorie dish.

Why Potatoes Have a Bad Reputation

Much of the fear comes from a large Harvard analysis of 120,877 US women and men followed for up to 20 years. It looked at how changes in each food were linked to weight change over every four years. The foods most strongly linked to gaining weight were potato chips (1.69 lb for each extra daily serving) and potatoes (1.28 lb), ahead of sugary drinks and red meat. Vegetables, whole grains, fruit, nuts and yogurt were linked to gaining less.

That is a real finding, but it describes potatoes as people typically eat them, often fried or with rich toppings, and it is observational, so it cannot prove cause. It sits alongside the trials above, in which people deliberately eating potatoes in a lower-calorie diet still lost weight. The sensible reading is not to avoid potatoes, but to avoid the ways of eating them that pile on calories.

Fries vs Baked: The Form Is What Matters

Large studies that separate potatoes by how they are cooked show the difference clearly:

• Type 2 diabetes. A 2025 BMJ study of 205,107 people followed for decades found that every three extra servings a week of French fries was linked to a 20 percent higher rate of type 2 diabetes, while baked, boiled or mashed potatoes combined were not significantly linked to it. Swapping potatoes for whole grains was linked to lower risk, but swapping them for white rice was linked to higher risk.
• Mortality. In an 8-year study of 4,440 adults aged 45 to 79, eating fried potatoes 2 to 3 times a week was linked to about double the risk of death compared with eating them rarely, and three or more times a week to 2.3 times the risk. Unfried potatoes showed no link.

The Glycemic Index Question

Potatoes do raise blood sugar quickly; most have a high glycemic index (GI). But the number varies a lot with the type and how they are prepared. In a North American study, boiled red potatoes eaten cold had a GI of 56, while the same potatoes eaten hot scored 89, instant mashed potatoes 88, baked Russets 77 and roasted white potatoes 72. Precooking Russet potatoes, refrigerating them and reheating them lowered the blood sugar response. An Australian study found new potatoes had lower GI values than larger, more mature ones.

For weight loss, GI matters less than calories: in the 12-week trial above, a low-GI diet did not produce more weight loss than a high-GI one, and people found the GI rules hard to follow. If you have diabetes or prediabetes, though, the practical tips are worth using: eat potatoes cooled or reheated, choose smaller new potatoes, and eat them with protein, fat and vegetables rather than on their own.

How to Eat Potatoes and Lose Weight

• Boil, steam or bake them, and keep the skin on for extra fiber.
• Make them part of a plate, not the whole plate: a fist-sized portion next to a palm of protein, such as chicken, fish, eggs or beans, and plenty of vegetables.
• Swap the toppings. Use plain yogurt instead of sour cream, salsa, herbs, mustard, or a little grated cheese instead of handfuls.
• Cook ahead and chill. Cooked, cooled potatoes in salads, or reheated the next day, raise blood sugar less.
• Keep fries and chips for occasional treats, not regular sides.
• Think about what the potato replaces. Swapping fries for a baked potato is a win; swapping a vegetable side for a second serving of potatoes is not.

Food choices work best alongside regular activity; how much exercise helps is covered in the best exercise to lose weight. For how other starchy staples compare, see is rice good for weight loss and which carbs are weight-loss friendly.

The Verdict

Potatoes are not the enemy of weight loss. Plain boiled potatoes are the most filling of common foods per calorie, and trials show people lose weight while eating them several times a week as long as total calories come down. What drives the bad reputation is the form: fries, chips and heavily topped potatoes are linked to weight gain, type 2 diabetes and higher mortality, while baked, boiled and mashed potatoes are not linked to diabetes. Boil, bake or steam them, keep the skin, mind the toppings and the portion, and potatoes can be a useful part of a weight-loss diet.