Sweet potatoes are a starchy and sweet tasting tuber. In addition to being nutrient-rich, they also have several medicinal and health properties. Sweet potatoes are very important energy and phytochemical sources in human nutrition. This article highlights the important sweet potato nutrition facts.
Sweet potatoes are very important food crops, especially in rural areas. I have realized that most people in these areas are unaware of sweet potato nutrition facts. They just eat the tuber because it’s a food that is tasty and easily produced. In my village, people grow a lot of sweet potatoes and they use them as breakfast during the harvest periods. After that, any excess produce is either sold or stored in holes dug in the ground (pfimbi).
All along I thought sweet potatoes were all starch and no nutrients. However, I realised that this wasn’t true at all. The truth is that sweet potatoes are rich in several nutrients. However, they are poor sources of fats and proteins. This makes them undesirable for weaning children as most low-income households do. Weaning children with sweet potatoes as the main dietary component usually results in protein-energy malnutrition.
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Sweet potato nutrition facts
Sweet potato roots and leaves
These are the most commonly consumed part of sweet potatoes. Tubers are the most economically important part of the plant. Sweet potato tubers are eaten as food, used for livestock feed and also used for industrial starch extraction. The tuber has different coloured skins ranging from yellow, orange, red, brown to purple and beige. The flesh of several sweet potato varieties also varies. Sweet potato tubers may have pink, violet, white, red, yellow, orange or purple flesh. The coloured sweet potatoes are rich in coloured phytochemicals that have many health benefits. I have eaten white, yellow, orange and purple coloured sweet potatoes. And try are all taste too, each one with its unique flavour.
Leaves may not be very important economically but they are highly nutritious. They are taken as medicine or used as healthy vegetables by different groups of people. Eating sweet potato leaves as vegetables can help boost your nutritional health.
Sweet potatoes have a high nutritional value
This is one of the most important sweet potato nutrition facts, however, it is usually overlooked. Most of us just dismiss sweet potatoes as mere tubers of low nutritional value. Studies show that sweet potatoes can provide you with many essential nutrients. The only exception being proteins and fats. This is because sweet potatoes are poor sources of proteins.
Eating sweet potatoes regularly can provide you with 90% of the nutrients per calorie required by most people. The tubers are a valuable source of carbohydrates, vitamins and minerals.
In brief, these are some of the important sweet potato nutrition facts:
- They can provide you with 100% of your Recommended Daily Allowance (RDA) for vitamin A and 49% RDA for vitamin C.
- Also, they can provide 10% RDA for iron and 15% of your RDA for potassium.
Sweet potatoes are not all simple starch: sweet potato nutrition facts
Most people make the simple mistake of thinking that sweet potatoes are like other tubers, “all starch and water plus no nutrients”. This is not entirely true. In addition to simple starch sweet potatoes are also rich in:
- Complex carbohydrates
- Dietary fibre
- Vitamin content, (provitamin A carotenoids, part of the vitamin B compliment, vitamin E and C)
- Bioactive compounds with nutraceutical properties.
Pink, orange, yellow and green sweet potato varieties are very rich in beta carotene as well as other carotenoids. On the other hand, orange-fleshed sweet potatoes are probably nature’s best source of beta carotene. This means they are a very good alternative for fighting vitamin A deficiency.
Sweet potatoes and improved blood vitamin A content
Most people may not know it but they may suffer from vitamin A deficiency. Vitamin A in the form of retinoids is mainly present in animal-based foods. A wrong imbalanced plant-based diet may cause problems of vitamin A deficiency. However, that may not be the case in a sweet potato-based diet. I have seen several organizations promoting orange-fleshed sweet potatoes and maize as a way to fight vitamin A deficiency. And I believe this is one of the best ways to do so! Why?
Studies show that sweet potatoes have a superior ability to improve your blood levels of vitamin A! This means they can do this better than most other plant-based vegetables. In many cases eating sweet potatoes can give you enough vitamin A activity to meet 90% of your needs. This value may be higher in the case of orange, yellow or green fleshed sweet potato tubers!
The carbohydrates in sweet potatoes
The main carbohydrate of sweet potatoes is starch. The starch content however differs from the sweet potato varieties. Some of the sweet potato varieties are very starchy. Whilst others have very low starch content. In addition to starch sweet potatoes also contain sugars such as sucrose, glucose, fructose and maltose.
Sweet potato leaves are more nutritious than the tuber itself
Some of the most important sweet potato nutrition facts come from the leaves. Leaves of the sweet potato plants have appreciable nutrient content. The leaves contain:
- More crude protein and fat than tubers.
- More crude fibre and ash.
- Vitamin A and C
- Minerals ( zinc, potassium, sodium, manganese, calcium, magnesium and iron).
- Higher protein content than tubers.
- More bioactive compounds than the tubers.
Some suggest that sweet potato leaves have low toxin levels. This includes low levels of substances like phytic acid, cyanide, tannins and oxalate.
Sweet potato leaves also contain a polyphenolic content 7-9 times higher than that of grape seed. This is very important since this explains the many medicinal and health benefits of sweet potatoes.
How cooking methods affect sweet potato nutrition facts
Sweet potatoes can be cooked in several ways which include boiling, baking, frying and powdered porridges. You can expect to lose some nutrients during cooking. Most of the time prolonged cooking and higher temperatures destroy more nutrients. However, eating sweet potatoes raw is not a very good option either. This is because sweet potatoes contain highly fermentable compounds and toxins that may cause bloating and gassing. Some people can eat loads of raw sweet potatoes and not feel any discomfort but most of us are not so lucky!
Also read: Avocados cause bloating: Why
Other sweet potato nutrition facts
Some people wonder if sweet potatoes are really sweet. The truth is that they are sweet. The total sugar content of sweet potatoes is higher than that of cassava roots. This is the reason why sweet potatoes are sweeter.
Also storing sweet potatoes for longer times makes them sweet. This is partly due to the hydrolysis of the starch in sweet potatoes to maltose which is sweeter. Also, the sweet potatoes lose some of their water during storage. This concentrates the sugars and makes the sweet potatoes sweet.
Nutritional value of sweet potatoes per 100 g
- Energy 86 kcal
- Carbs 20.1 g
- Starch 12.7 g
- Sugars 4.2 g
- Dietary fibre 3.0 g
- Fat 0.1 g
- Protein 1.6 g
- Vitamin A equivalents 709 ug (89%)
- Beta carotene 8509 ug (79%)
- Thiamine (B1) 0.1 mg (9%)
- Riboflavin (B2) 0.1 mg (8%)
- Niacin (B3) 0.61 mg (4%)
- Pantothenic acid (B5) 0.8 mg (16%)
- Vitamin (B6) 0.2 mg (15%)
- Folate (B9) 11 ug (3%)
- Vitamin C 2 mg (3%)
- Vitamin E 0.26 mg (2%)
- Calcium 30 mg (3%)
- Iron 0.6 mg (5%)
- Magnesium 25 mg (7%)
- Phosphorus 49 mg (7%)
- Potassium 337 mg (7%)
- Sodium 55 mg (4%)
- Zinc 0.3 mg (3%)
Please understand this, this is a general sweet potato nutrient list. The nutrients in each sweet potato differ according to several factors including variety and soil in which the crop is grown. For example, sweet potatoes with different flesh colours contain different nutrients and phytochemicals. However, most sweet potatoes varieties may follow the sweet potato nutrition pattern.
One other important thing that separates sweet potatoes from many other tubers is the micronutrient profile. Sweet potatoes have a very rich micronutrient profile thus they can act as a functional food to combat micronutrient deficiencies. This is especially true with coloured sweet potato varieties.
Also, sweet potatoes are not overly rich in sodium but rather in potassium. This represents a more desirable sodium to potassium ratio. Whilst sodium is needed by the body, we tend to consume too much of it resulting in several health problems. Too much sodium and less potassium is associated with kidney problems.
If you understand technical jargon you can also read these two articles.
To be frank, sweet potatoes are like a superfood in the face of modern day super refined ultra-processed foods. Sweet potatoes are not starch and water as most people assume. Sweet potatoes are a nutrient-rich food that can be part of your regular diet. At the end of the day, what is very important is balancing your diet. I remember debating that sweet potatoes have a better satiating and healthy effect than your white rice. That’s why I decided to write about these sweet nutrition facts. Because I knew that white rice without anything else is just a diabetes mellitus trap! However, that is a story for another day.