100 g of sweet potato carries over 8,500 Āµg of beta-carotene ā comfortably more than a day's vitamin A requirement, and the deeper the orange, the higher the content.
The "diet food" reputation, though, comes with a condition. Baked sweet potato has a glycaemic index above 90; boiled sits in the fifties. High dry heat breaks starch down into sugars, so the same vegetable becomes a different food depending on the method.
Key benefits
- 1
It covers your vitamin A
Beta-carotene converts to vitamin A only as the body needs it, so there is little risk of excess. Vitamin A supports vision in low light, the barrier function of skin and mucous membranes, and immune cell activity. One medium sweet potato meets a day's requirement.
- 2
It feeds gut health and keeps you full
3 g of fibre per 100 g, plus **resistant starch** that increases when the cooked potato is cooled. Resistant starch escapes absorption in the small intestine and reaches the colon, where it feeds beneficial bacteria and supports short-chain fatty acid production.
- 3
Its potassium helps with blood pressure
337 mg of potassium per 100 g helps the body excrete sodium, which pushes blood pressure down. The higher your sodium intake, the more that potassium matters.
- 4
It is loaded with antioxidant pigments
Orange varieties are rich in carotenoids; purple ones in anthocyanins. Both groups of pigments have been shown to reduce markers of oxidative stress. Deeper colour means more of them.
How to eat it well
- Boil or steam if blood sugar is a concern. The same potato baked raises glucose considerably faster.
- Let it cool. Cooking then refrigerating increases resistant starch and flattens the glucose response.
- Eat the skin. Fibre and polyphenols concentrate there. Scrub it well and leave it on.
- Add fat. Beta-carotene is fat-soluble, so a drizzle of olive oil or a side of nuts or yoghurt improves absorption.
- Pairing it with protein ā eggs, tofu, chicken ā flattens the glucose response of the whole meal.
What to watch out for
- Relatively high in oxalate, so go easy if you have a history of calcium oxalate kidney stones.
- If you are restricting potassium for chronic kidney disease, portion it carefully.
- A large portion at once can cause gas and bloating from the fibre and oligosaccharides.
- It is a carbohydrate food. Adding it on top of your usual rice or bread increases total intake ā swap rather than stack.
- Cut away sprouted or blackened parts before cooking.
Nutrition
Approximate values per 100 g edible portion.
- Calories
- 86 kcal
- Carbohydrates
- 20.1 g
- Fiber
- 3.0 g
- Sugars
- 4.2 g
- Protein
- 1.6 g
- Beta-carotene
- 8,509 Āµg
- Potassium
- 337 mg
- Vitamin C
- 2.4 mg
Key nutrients
- Beta-carotene
- Vitamin A
- Fiber
- Potassium
- Manganese