Sweet potatoes for weight loss

Why sweet potatoes support weight loss

Are sweet potatoes good for weight loss?

The weight loss case comes down to two things working together: fiber and low calorie density. A medium sweet potato, baked in its skin, has about 103 calories and 3.8 grams of fiber, according to USDA FoodData Central. At about 90 calories per 100 grams, you get a good-sized portion for not many calories.

Fiber and appetite. Fiber-rich meals are larger in volume, lower in energy density and take longer to eat, according to a review of dietary fiber in foods, and gel-forming soluble fibers may slow how fast your stomach empties. The same review adds a useful limit: the extra food in your stomach may bring on fullness sooner, but that feeling is short term. Fiber helps. It won't carry you from lunch to dinner by itself. Mayo Clinic has a fuller guide to dietary fiber if you want to read more.

Fullness compared with other foods. Older versions of this advice claim that sweet potatoes increase fullness more than other foods with the same calories. We looked and couldn't find a human study showing that, and we aren't going to invent one. The review that claim was tied to is a broad look at sweet potato nutrition and medicinal properties, not a fullness trial. What you can count on is the fiber and the volume.

The closest human trial. In a Taiwanese trial, 58 overweight office workers either ate a white sweet potato meal replacement formula (132 grams a day) or stayed on their normal diet for 8 weeks. Weight and body fat dropped in both groups, and the formula group's weight and body fat fell about 5%. That's encouraging, with limits. It was a manufactured formula rather than a baked orange sweet potato, it replaced meals, and it ran 8 weeks. It tells you more about portion-controlled meal replacement than about the vegetable.

Sweet potatoes aren't the only food that works this way. For a deeper look at what delivers results, see our guide to the best foods for weight loss, and our look at carrots for weight loss for a lower-calorie vegetable that gets a similar sugar scare.

Sweet potato nutrition facts

What's in a medium sweet potato?

One medium sweet potato has about 100 calories and essentially no fat. That alone makes it a smart choice, but the real story is what comes with those calories.

One medium sweet potato (114 g), baked in skin, rounded from USDA FoodData Central

You may see "over 400% of your daily vitamin A" elsewhere, including on the American Sweet Potato Marketing Institute's nutrition page, which says "over four times" the daily amount. That figure comes from an older Daily Value. Against the current one, it's about 122%, which is still a lot from one vegetable. A medium sweet potato gives you more vitamin A than you need in a day.

The fiber comes in both soluble and insoluble forms, and fiber in general supports digestive health and may lower the risk of type 2 diabetes and heart disease. If you want to understand why fiber matters so much for long-term health and weight, our Ultimate Guide to Dietary Fiber covers the full science.

Sweet potatoes also bring vitamin B6 and potassium. Vitamin B6 helps your body use protein and carbohydrates for energy. Potassium helps your nerves and muscles work and keeps your heartbeat regular, and a potassium-rich diet helps offset some of sodium's harmful effects on blood pressure. You may read that potassium is linked to burning more fat. We couldn't back that up, so leave it out of your reasons. The NIH also has a potassium fact sheet if you want the detail.

Sweet potato glycemic index

Do sweet potatoes keep blood sugar stable?

This is the part most sweet potato articles get wrong, and our older version of this post was one of them. Sweet potatoes are often described as low glycemic. Harvard's Nutrition Source says the opposite: they have a high glycemic index and glycemic load, almost as high as a white potato. Both can be true, because cooking method changes the number a lot.

Glycemic index by food & cooking method (Atkinson 2008 and the University of Sydney GI database)

The 2008 international tables list boiled sweet potato at 63 and boiled white potato at 78. The University of Sydney's database shows why you see so many different answers: the same cultivar came in at 46 boiled for 20 minutes and 83 baked with the skin on for 45 minutes. Baking turns more of the starch into sugars and quick-digesting starch.

Run the arithmetic for a medium sweet potato with about 20 grams of net carbs. At a GI of 46, the glycemic load is about 9. At a GI of 83, it's about 17. Neither is alarming at that portion, and a glycemic load under 20 isn't considered high. The trouble starts with an oversized potato and nothing else on the plate.

So the old promise that sweet potatoes prevent a blood sugar crash doesn't hold in general. Foods that raise blood sugar quickly can leave some people hungry again sooner, and you can work with that:

• Boil or steam when blood sugar is your concern. Boiled sweet potatoes test much lower than baked ones.
• Eat them with protein and vegetables. A mixed meal slows things down compared with a sweet potato by itself.
• Keep the skin on. It adds fiber, though it won't erase the difference between baked and boiled.
• Watch the portion. A smaller amount of carbohydrate always means a smaller effect.

Other sweet potato health benefits

What else do sweet potatoes do for you?

Weight management aside, sweet potatoes offer benefits that support your overall health. Harvard lists them as a source of vitamin A in the form of beta-carotene, vitamin B6, vitamin C, potassium and fiber. Orange flesh is richest in beta-carotene, which gives them their color, and purple flesh is richer in anthocyanins.

Those pigments act as antioxidants. A review of functional components in sweet potato reports antioxidant activity for its carotenoids and preventive effects for some diseases, mainly in the lab and in animal models. That's the honest scale of it. Eating produce rich in these compounds is a good idea. Expecting one vegetable to prevent chronic disease isn't.

The same goes for inflammation. Chronic low-grade inflammation is closely tied to metabolic problems and obesity, which is why it comes up in weight loss articles. The reference usually cited here is a study in mice given a concentrated purple sweet potato pigment for 20 weeks on a high-fat diet. The treated mice gained less weight and had less inflammation in the brain. It's interesting biology, but it's a pigment extract in mice, not a side dish in people.

The potassium content supports heart health by helping manage blood pressure. Fiber plus vitamins A and C also supports immune function and gut health, and both play a part in how effectively your body manages weight over time.

How to eat sweet potatoes for weight loss

How should you eat sweet potatoes?

The best part about sweet potatoes is how easily they fit into almost any meal. The simplest place to start is a straight swap for white potatoes or refined starchy sides. Roasted, mashed or baked, you get the same preparation options with more fiber.

• Baked fries. Toss wedges with a light drizzle of olive oil and your favorite seasoning, then bake. They make a satisfying alternative to standard french fries, with far less oil. Measure the oil: 1 tablespoon is about 120 calories.
• Protein bowls. Roast a batch at the start of the week and top them with chicken, beans or eggs, plus whatever vegetables you have on hand.
• Soups and stews. They blend well, adding natural sweetness and body to meals that are already great for weight loss.
• Meal prep. They're one of the most practical batch-cook staples you can add to your rotation, since they store well and reheat easily. Our Complete Meal Prep Guide has plenty of ideas for building them into your week.
• Breakfast. A leftover roasted sweet potato with eggs turns a carb side into a meal with staying power.

Cool cooked sweet potatoes within 2 hours and keep them in the fridge for 3 to 4 days, the same as any leftovers.

Sweet potato portions & toppings

How much sweet potato is too much?

One practical note: keep your portions reasonable. A medium sweet potato is the right serving size for most meals, and at about 100 calories it fits comfortably into a calorie-conscious plan. The ones at the grocery store are often much larger than the 114-gram medium USDA uses, so a kitchen scale can be a real eye-opener.

How the toppings add up, rounded from USDA FoodData Central

That's nearly three times the calories, and it's still a modest serving by holiday standards. Butter, brown sugar and marshmallows turn a nutritious vegetable into a dessert. We aren't against dessert. Just call it that and count it that way. Prepared simply, a sweet potato is one of the easier carbs to fit in.

Putting sweet potatoes into practice

What should you do next?

Sweet potatoes deserve their place in a weight loss diet. The fiber helps you stay full and the calorie-to-nutrient ratio is hard to beat. Just don't count on them to keep your blood sugar flat when they're baked and eaten alone.

They're also enjoyable to eat, which matters more than most nutrition advice admits. A healthy diet you'll stick to is far more valuable than a perfect one that feels like punishment.

Knowing all this doesn't get dinner cooked, though. If the hard part is the planning and the cooking, our Clean Eatz Kitchen Weight Loss Meal Plan handles that with portion-controlled, calorie-controlled meals you heat in a few minutes. Or build your own plan from the meals you like. There's no subscription, so a week you fall off the plan doesn't cost you a fridge full of food.

Make it easy withWeight Loss Meal PlanFrom $89.95View plan