Curried Sweet Potato and Red Lentil Soup
A warming, fiber-rich soup that combines sweet potatoes and protein-packed lentils for steady energy and balanced blood sugar throughout your day.
This nourishing soup is a masterclass in low-glycemic cooking, thoughtfully designed to support stable blood sugar levels while delivering exceptional flavor. Sweet potatoes, despite their name, have a moderate glycemic index—especially when paired with protein-rich red lentils and healthy fats from olive oil. The lentils provide soluble fiber that slows glucose absorption, while the aromatic spices enhance insulin sensitivity.
The combination of grated apple and warming curry spices creates natural sweetness without added sugars, and the fresh ginger has been shown to improve glycemic control. By blending the soup to a smooth consistency and adding a splash of milk, we create a satisfying, creamy texture that promotes fullness and prevents blood sugar spikes. The lime juice at the end brightens the flavors while adding vitamin C, which may help improve glucose metabolism.
For optimal blood sugar management, enjoy this soup as part of a balanced meal. Consider starting with a small green salad dressed with vinegar to further blunt the glycemic response, and pair the soup with a source of lean protein if serving as a main course. The high fiber content (from both lentils and sweet potatoes) makes this an excellent choice for sustained energy without the afternoon crash.
Blood Sugar Impact
Moderate glycemic impact with a GL of 20.6, though the low GI of 30 suggests a gradual rise in blood sugar. The combination of fiber-rich lentils and sweet potatoes should provide sustained energy for 2-3 hours without sharp spikes.
Blood Sugar Tips
- ✓ Add a protein source like grilled chicken or a dollop of Greek yogurt to further slow glucose absorption and extend satiety
- ✓ Eat a small handful of nuts or seeds before the soup to add healthy fats that will blunt the glycemic response
- ✓ Take a 10-15 minute walk after eating to help muscles absorb glucose and reduce post-meal blood sugar elevation
🥗 Ingredients
- 2 tsp medium curry powder
- 3 tbsp olive oil
- 2 pcs onions, grated
- 1 pcs eating apple, peeled, cored and grated
- 3 pcs garlic cloves, crushed
- 20 g fresh coriander stalks, chopped
- 1 tbsp fresh root ginger, grated
- 800 g sweet potatoes, peeled and grated
- 1200 ml low-sodium vegetable stock
- 100 g red lentils
- 300 ml milk
- 1 tbsp fresh lime juice
- 2 tsp medium curry powder
- 3 tbsp olive oil
- 2 pcs onions, grated
- 1 pcs eating apple, peeled, cored and grated
- 3 pcs garlic cloves, crushed
- 0.7 oz fresh coriander stalks, chopped
- 1 tbsp fresh root ginger, grated
- 1.8 lb sweet potatoes, peeled and grated
- 5.1 cups low-sodium vegetable stock
- 3.5 oz red lentils
- 1.3 cups milk
- 1 tbsp fresh lime juice
👨🍳 Instructions
- 1
Place a large soup pot over medium heat and add the curry powder directly to the dry pan. Toast the spices for about 2 minutes, stirring frequently, until fragrant and slightly darkened. This step releases essential oils and deepens the flavor profile.
- 2
Pour the olive oil into the toasted spices and stir immediately as they sizzle. The oil will help distribute the curry flavor throughout the soup and provides healthy fats that slow glucose absorption.
- 3
Add the grated onions, grated apple, crushed garlic, chopped coriander stalks, and grated ginger to the pot. Season with a pinch of salt and pepper. Cook gently over medium-low heat for 5 minutes, stirring occasionally, until the vegetables soften and become aromatic.
- 4
While the aromatics cook, peel the sweet potatoes and grate them using the large holes of a box grater. Grating rather than cubing reduces cooking time and creates a smoother final texture.
- 5
Add the grated sweet potatoes to the pot along with the vegetable stock, red lentils, and milk. Stir well to combine all ingredients. The lentils will cook directly in the soup, releasing starches that naturally thicken the broth.
- 6
Bring the mixture to a gentle simmer, then reduce heat to maintain a steady, gentle bubble. Cover the pot and cook for 20 minutes, stirring occasionally, until the sweet potatoes are completely tender and the lentils have broken down.
- 7
Remove the pot from heat and use an immersion blender to puree the soup until completely smooth and creamy. If you don't have an immersion blender, carefully transfer the soup in batches to a countertop blender, being cautious with the hot liquid.
- 8
Stir in the fresh lime juice, which brightens the flavors and adds a pleasant acidity. Taste and adjust seasoning with additional salt and pepper if needed. Serve hot, garnished with roughly chopped fresh coriander leaves. For optimal blood sugar control, pair with a protein source or enjoy after eating a small salad.
📊 Nutrition Per Serving
| Per Serving | Whole Dish | |
|---|---|---|
| Calories | 348 | 2086 |
| Carbs | 38g | 231g |
| Sugars | 6g | 33g |
| Natural Sugars | 6g | 33g |
| Protein | 10g | 57g |
| Fat | 20g | 121g |
| Saturated Fat | 7g | 42g |
| Unsaturated Fat | 13g | 79g |
| Fiber | 13g | 78g |
| Soluble Fiber | 4g | 23g |
| Insoluble Fiber | 9g | 55g |
| Sodium | 107mg | 641mg |
Predicted Glucose Response
What if you...
Estimated model — individual responses vary. Not medical advice.
🔄 Lower GI Swaps
Sweet potatoes have a high glycemic index (63-70). Butternut squash has a lower GI of 51, while cauliflower and turnips are very low-GI vegetables that add creaminess and bulk without spiking blood sugar.
Regular apples have a GI of 36-40. Green apples are slightly lower in sugar content. Alternatively, lemon provides acidity without the sugar load, and coconut cream adds richness with minimal impact on blood glucose.
Regular milk contains lactose with a GI of 46. Unsweetened nut milks have virtually no impact on blood sugar, while heavy cream provides richness with minimal carbohydrates and a negligible glycemic response.
While onions have a low GI, reducing the quantity or using celery instead lowers the overall carbohydrate content of the soup, further reducing glycemic load without sacrificing flavor depth.
Commercial vegetable stocks often contain added sugars, starches, or maltodextrin that can raise blood sugar. Bone broth and quality chicken stock provide flavor with zero carbohydrates and no glycemic impact.
🔬 The Science Behind This Recipe
This warming soup is a masterclass in blood sugar management, combining ingredients that work synergistically to keep your glucose levels steady. Sweet potatoes, despite their natural sweetness, have a surprisingly moderate glycemic index around 44-63 (depending on cooking method), and when paired with red lentils—a legume powerhouse packed with protein and soluble fiber—the overall glycemic impact drops significantly. Red lentils contain about 8 grams of protein and 8 grams of fiber per half-cup, which dramatically slows digestion and creates a gentle, sustained release of glucose rather than a sharp spike. The fiber forms a gel-like substance in your digestive tract that acts as a physical barrier, preventing rapid sugar absorption.
The curry powder and olive oil aren't just flavor enhancers—they're metabolic allies. Turmeric, a key component of curry powder, contains curcumin, which research suggests may improve insulin sensitivity and reduce inflammation. The healthy fats in olive oil further slow gastric emptying, meaning your stomach takes longer to process the meal and release sugars into your bloodstream. This is why adding fat to carbohydrate-rich foods consistently lowers their glycemic response. The onions and garlic contribute additional fiber and sulfur compounds that support healthy glucose metabolism.
With a glycemic load of 20.6 per serving, this soup falls into the "medium" category, but context matters. Eat it as part of a complete meal—perhaps starting with a small salad to pre-load with fiber—and you'll minimize any glucose elevation even further. The combination of legumes, vegetables, and healthy fats makes this soup incredibly satiating, helping you avoid the blood sugar rollercoaster that leads to energy crashes and cravings later in the day.