The 'Five a Day' Rule and Starchy Carbs
For many years, national health guidelines, including those from the NHS, have promoted the 'five a day' message to encourage people to eat more fruits and vegetables. However, this guideline comes with specific definitions for what constitutes a portion. White potatoes, along with other starchy root vegetables like yams and cassava, are placed in a different food group: starchy carbohydrates. The key reason for this is their primary nutritional contribution to the diet.
Potatoes are energy-dense, providing a significant amount of carbohydrates that our bodies use for fuel. This places them in the same category as other carbohydrate sources such as bread, pasta, and rice. While they do contain important nutrients like fibre, potassium, and B vitamins, they do not offer the same broad spectrum of vitamins, minerals, and antioxidants that a wider variety of non-starchy fruits and vegetables provide. The five-a-day recommendation is designed to encourage dietary diversity across different nutrient profiles.
Starchy vs. Non-Starchy Vegetables: A Nutritional Breakdown
The distinction between starchy and non-starchy vegetables is crucial for understanding the five-a-day rule. Non-starchy vegetables are typically lower in calories and higher in fibre and water content. Eating a variety of these vegetables, from leafy greens to bell peppers and broccoli, ensures a wider intake of different micronutrients. Starchy vegetables, while healthy, are a concentrated source of energy, and relying on them for your five a day would neglect other important food groups.
Common starchy vegetables:
- White potatoes
- Yams
- Cassava
- Plantain
- Sweetcorn
Common non-starchy vegetables:
- Broccoli
- Spinach
- Carrots
- Bell peppers
- Cucumbers
- Tomatoes
- Mushrooms
The Role of Potatoes in a Balanced Diet
Just because potatoes don't count towards the five a day doesn't mean they aren't part of a healthy diet. They are a valuable source of nutrients and can be a filling and delicious component of a meal. For instance, a baked potato with the skin on is a great source of fibre, and potatoes provide a good dose of potassium. The issue isn't their nutritional value in isolation, but how they are typically consumed. When potatoes are a main part of a meal, they displace other fruits and vegetables, potentially reducing the nutritional variety of the diet.
This is why health organisations emphasize that for a balanced diet, it's best to consume a wide range of fruits and vegetables in addition to starchy foods like potatoes. Instead of viewing potatoes as a 'failure' to eat a vegetable, it's more accurate to think of them as an important, separate food group. The real goal is to diversify your plant-based intake, and including a mix of both starchy and non-starchy options is the healthiest approach.
Sweet Potatoes and the Five a Day Anomaly
An interesting exception to the rule is the sweet potato. While also a root vegetable, sweet potatoes do count as one of your five a day. The primary reason is their different nutritional profile. Sweet potatoes are a rich source of beta-carotene, a powerful antioxidant that the body converts into Vitamin A. This unique nutritional property differentiates them from white potatoes and other starchy root vegetables, placing them in the non-starchy vegetable category for the five-a-day calculation. Parsnips, swedes, and turnips also count for this reason. This example highlights that the classification is based on nutritional composition rather than just botanical categorisation.
| Feature | White Potatoes | Sweet Potatoes | Non-Starchy Vegetables |
|---|---|---|---|
| Classification for '5-a-day' | Starchy Carbohydrate | Non-Starchy Vegetable | Non-Starchy Vegetable |
| Primary Nutritional Role | Energy source (starch) | Energy and high beta-carotene | Wide range of vitamins/minerals |
| Key Nutrients | Fibre, Potassium, Vitamin B6 | Beta-Carotene, Vitamin C, Manganese | Wide variety of micronutrients |
| Carbohydrate Density | High | High | Low |
| Example Use | Fries, mashed potatoes, roasts | Baked, roasted, curries | Salads, stir-fries, sides |
Conclusion: The Importance of Variety
Ultimately, the reason why potatoes don't count as five a day is a matter of nutritional classification, not a judgment on their inherent value. They are correctly considered a healthy starchy food, providing essential energy and nutrients. The five-a-day message serves as a reminder to eat a wide variety of plant-based foods, not just rely on a few favourites. By understanding this distinction, you can build a more balanced plate that includes a colourful array of fruits and non-starchy vegetables alongside your potatoes, ensuring you get a complete range of the beneficial vitamins and antioxidants your body needs. For more details on portion sizes and what counts, consult the British Dietetic Association's guidance on fruit and vegetables.
