Potatoes contain a variety of nutrients and are major contributors of important minerals to the diet such as potassium and chromium. Despite what some people think, potatoes (boiled with skin), are naturally free of fat, high in carbohydrates (complex carbohydrates) and naturally low in sodium.

Added elements such as oil, butter or cream create a higher fat content in potatoes. 1medium potato provides only 498kJ and approximately 24g of carbohydrates. That is the equivalent of one and a half carbohydrate servings. According to Professor Esté Vorster, Director: Africa Unit for Transdisciplinary Health Research at the Faculty of Health Sciences of North West University: “Potatoes, when boiled in their skin, have low energy values and are ideal for both slimming and maintaining a healthy body weight.”

One needs to remember that it is the fillings and cooking method that effective the kilojoule content of potatoes. Team your potato up with low fat, nutritious fillings. Sensible eating is not about restricting certain food groups from the diet. It is about achieving balance and listening to your body and adopting a longer-term healthy eating plan that will continually benefit you.

Potatoes, cooked with skin, provide a wide range of nutrients. They are high in carbohydrates and the mineral chromium. They also have one of the highest levels of potassium when compared to other vegetables and starchy foods.

Below is a list of the vitamins and minerals contained in 1medium potato.

Vitamins Per single 150g serving %NRV*
Vitamin B2 (mg) 0.1 5%
Niacin (mg)** 2.4 15%
Vitamin B6 (mg)** 0.5 29%
Vitamin C (mg) 8.2 8%
Pantothenic acid (mg)** 0.8 17%
Copper (mg) 0.2 27%
Chromium (ug) 15 43%
Iron (mg) 1.8 10%
Magnesium (mg) 39.1 9%
Manganese (mg) 0.3 14%
Phosphorus (mg) 98.9 8%
Potassium (mg) 710 **
Zinc (mg) 1.5 13%

Information for cooked potato with skin

*Nutrient Reference values (NRV’s) for individuals 4 years and older expressed per single serving.
**NO NRV available

Potatoes have been unfairly criticized for their ranking on the GI. In fact there are a number of complexities in the measure and methodological weaknesses inherent in the determination of GI, which severely limits the simple classification of a given food as high, medium or low on the GI, as well as the application of the GI for the purpose of food selection (Franz 2006). First and foremost, it must be emphasized that the GI is not an inherent property of a food but, rather, the metabolic response of an individual to a food (Pi-Sunyer 2002). Thus, the GI of a carbohydrate-rich food can Vary greatly depending on a number of factors, including:

  • Processing/preparation.
  • Variety, origin, maturation.
  • Addition of other macronutrients (protein, fat, fiber).

Ways to decrease the GI of potatoes:

  • Combine potatoes with protein rich food such as low fat cottage cheese or tuna.
  • Allow potato to cool after cooking.

In 2011, Potatoes South Africa conducted a hydrolysis index test. This screens the GI of foods. Hydrolysis index (HI) values predict that floury potatoes, such as the Darius cultivar, could possibly have an intermediate GI, while waxy potatoes such as the Mondial cultivar are predicted to have a high GI, as generally accepted for potatoes by the Glycaemic Index Foundation of South Africa (GIFSA).

“This provides evidence to suggest that, different cultivars with different dry matter and starch contents, as well as those grown in different regions and under different growth conditions could have different GI values.” Nicolette Gibson, Faculty of Natural and Agricultural Sciences, University of Pretoria.

In conclusion:

Like the low-carbohydrate craze that preceded it, the GI has enjoyed increasing popularity despite the lack of research to support its efficacy as a dietary tool for weight loss, disease prevention, and/or health promotion. However, unlike the low-carbohydrate diets whose popularity could be attributed in a large part to their simplicity (i.e., just eliminate carbohydrates from the diet), the GI is considered rather complex and this is made even more complex by the multitude of factors that can impact it (e.g., processing, preparation, maturation, the addition of other macronutrients, time of day, etc.). Until large-scale studies are done using the GI in a variety of circumstances and disease conditions, South Africans should strive to follow the food based dietary guidelines.

While high-protein, low-carbohydrate eating plans may show some external physical results, it is not necessarily doing us any favours in the long term. Low carbohydrate diets can result in fatigue and dehydration caused by increased protein metabolism, which also places strain on our kidneys. By restricting our intake of carbohydrates we also starve the body of the dietary fibre that is important for healthy digestion. The starch in potatoes yields glucose that is essential for our mental and physical energy, so yes, you really do need carbohydrates in your diet and potatoes are an ideal source.

Your body needs a variety of foods in a balanced diet. But use a little nutrition sense when selecting starches. Chose starchy foods that contain dietary fibre, are close to their natural form (not overly processed), and are high in key nutrients.

Potatoes should be stored in a dark, dry and cool place that is well-ventilated. Keep them separate from pungent vegetables (which give off gasses that promote decay in potatoes). Take them out of plastic bags.

The green colour sometimes found in potatoes is caused by chlorophyll and indicates that solanine is present. It is usually due to the potato’s exposure to light. Solanine is a natural toxin that is only really harmful in large doses. Nevertheless, if a potato is green in parts, simply cut off the green bit and prepare the remaining potato as usual.

Sprouting potatoes are typically not fresh but can be eaten if you break off the sprouts.