Potatoes and weight gain

In the U.S., people eat an average of 126 pounds of potatoes per person each year (1) and in France, per capita consumption of potatoes is 65 kg (143 pounds): 40 kg in fresh form and 25 kg in processed form (11). However, potatoes don’t count as a vegetable on Harvard’s Healthy Eating Plate because they are high in the type of carbohydrate that the body digests rapidly, causing blood sugar and insulin to surge and then dip (in scientific terms, they have a high glycemic load). For example, a cup of potatoes has a similar effect on blood sugar as a can of cola or a handful of jelly beans (2,3).  This roller-coaster-like effect on blood sugar and insulin can result in people feeling hungry again soon after eating, which may then lead to overeating (4). Over the long term, diets high in potatoes and similarly rapidly-digested, high carbohydrate foods can contribute to obesity, diabetes, and heart disease (5-10).

Potatoes and Weight Gain

Potatoes seem to be a particular culprit for weight gain and diabetes. A 2011 study by Mozaffarian et al. that tracked the diet and lifestyle habits of 120,000 men and women for up to 20 years looked at how small food-choice changes contributed to weight gain over time. People who increased their consumption of French fries and baked or mashed potatoes gained more weight over time - an extra 3.4 and 1.3 pounds every four years, respectively (8). People who decreased their intake of these foods gained less weight, as did people who increased their intake of other vegetables. A similar long-term study found that high potato and French fry intakes were linked to a greater risk of diabetes in women, and that replacing potatoes with whole grains could lower diabetes risk (10).

Potatoes do contain important nutrients - vitamin C, potassium, and vitamin B6, to name a few. But the potato is not the only source of these nutrients, nor is it the best: For example broccoli has nearly nine times as much vitamin C as a potato and White beans have about double the potassium. 

What to Eat instead of Potatoes?

• Whole grains are an excellent choice, especially minimally processed grains such as brown rice and quinoa.

• Beans can also stand in as a “starchy” side dish; they are high in fiber and protein, and cause less of a spike in blood sugar than processed grains.

• If you’re looking for that mashed-potato texture, try this recipe that uses cauliflower instead.

If you want to swap sweet potatoes for white potatoes, you’ll still need to go easy on the portions: Sweet potatoes have a moderate glycemic index and glycemic load. The glycemic index for cooked sweet potatoes is 46, while it reaches 78 for boiled potatoes, 82 for French fries and 65 for steamed potatoes (with skin) (11). The best alternative would be to mix sweet potatoes with some cruciferous to balance the glycemic load of your meal.