It is surprisingly easy for urban myths to take hold and once accepted there is not much questioning of it. One myth that refuses to die is that sweet potatoes have less sugar than potatoes.
When you think about it for a moment, the name should give us a clue. Sweetness comes from sugar so logic should dictate that a sweet potato has more sugar than a regular one.
Indeed this is the case and by a bigger margin than you might think. The average sweet potato has 5,4g of sugar which is over four times as much as a regular potato which has only 1.3 g. When you drill down further we find that sweet potato has seven times as much sucrose as a regular potato.
Let me repeat that, a sweet potato has four times as much sugar and seven times as much sucrose as a regular potato.
So where did the myth come from? There is a lot of confusion about the terminology used to describe carbohydrates. Total carbohydrate content of a food includes what we call “good” carbs, which provide fibre and do not get absorbed quickly as well as “bad” carbs, or “sugars” which are absorbed quickly. It is this latter type, which goes to the hips.
Potatoes do have a higher amount of fibre (also called resistant starch) than sweet potatoes. But this does not get absorbed. This “good” carb does not go to the hips. It stays in the gut as fibre and helps with the workings of the gut.
Many of us get spooked by the term “starch” because it has been assumed that it is full of calories. The resistant starch in potatoes does not add to your total calorie intake because it does not get absorbed. The term “fibre” is better understood but means the same.
Nutrition has been made harder than it needs to be. We can all eat a healthy diet by focusing on the basics. This means good quality protein (animal or vegetable), good fats, vegetables and fruit.
Potatoes are a vegetable and are a good source of fibre, B group vitamins, potassium, vitamin C and folate. They are versatile, going well with many other foods and easy to prepare.
On top of all that, it is easy to get your children to eat them, which is not something you can say for all vegetables.
So with plenty of healthy fibre and way less sugar than sweet potatoes, make potatoes a regular part of your healthy eating plan.
Dr Joe is the health ambassador for locally grown fresh potatoes.