Understanding the Glycemic Index
What is the Glycemic Index (GI)?
The glycemic index is a system used to classify carbohydrate-containing foods based on their effect on blood glucose levels. Foods are ranked on a scale from 0 to 100, where higher numbers indicate a faster and more significant rise in blood sugar. The GI scale is broken down into three categories:
- Low GI: 55 or less (e.g., most fruits, vegetables, beans)
- Medium GI: 56 to 69 (e.g., whole-grain products)
- High GI: 70 or higher (e.g., white bread, white rice)
For individuals with diabetes or those managing blood sugar, choosing foods with a lower GI is often recommended to prevent spikes in blood glucose. However, a food's GI is not the only factor to consider, as portion size and combination with other nutrients like protein and fiber also play a crucial role.
Factors That Influence a Food's GI
Several factors can alter a food's glycemic response:
- Processing: How a food is processed can dramatically change its GI. For example, popped or puffed cereals often have a higher GI than the unprocessed grain.
- Fiber Content: A higher fiber content, especially soluble fiber, slows down digestion and the absorption of sugar, resulting in a lower GI.
- Combination of Foods: Pairing a high-GI food with low-GI foods, such as vegetables, protein, or healthy fats, can balance the overall glycemic effect of a meal.
The Glycemic Index of Amaranth Roti
Pure Amaranth Flour vs. Composite Flour
The most important takeaway regarding what is the GI of amaranth roti is that the answer is not a single number, but rather a spectrum based on its composition. While pure, cooked amaranth grain has a high GI of around 97, and some pure flour estimates reach 107, amaranth is rarely consumed on its own. The GI of a roti made entirely from pure amaranth flour would be considered high.
However, the story changes completely when amaranth is used as a composite flour. Studies involving non-insulin-dependent diabetic subjects have shown that combining amaranth with other flours significantly lowers the overall GI. A 1997 study found that an amaranth-wheat composite flour roti had a much more favorable glycemic response than pure amaranth.
Experimental GI Values for Amaranth-Based Foods
According to research published on PubMed, specific ratios have yielded measurable GI values:
- Amaranth-Wheat (25:75) Roti: The GI was measured at 65.6%, which is in the medium GI range, leaning towards low.
- Amaranth-Wheat (50:50) Roti: This higher ratio resulted in a GI of 75.5%, placing it in the high GI category, though still lower than pure amaranth.
These findings prove that a simple change in the flour ratio can shift a roti from a high-GI food to a medium-GI food, a critical distinction for dietary planning.
Strategies to Lower the GI of Amaranth Roti
For those aiming for an even lower GI, several strategies can be employed when preparing amaranth roti.
The Power of Multigrain Flours
Mixing amaranth with other low-GI flours is the most effective method. Some excellent choices include:
- Chickpea Flour (Besan): With a very low GI of around 10 for the flour itself, besan can drastically reduce the overall GI of the composite roti.
- Barley Flour: Ranging from a low to medium GI (53-66), barley is rich in fiber and beneficial for blood sugar control.
- Whole Wheat Flour: Even regular whole wheat flour, with a GI around 54, is a good partner for amaranth.
Incorporating High-Fiber Vegetables
Adding finely grated or pureed vegetables can increase the fiber content and moisture, further lowering the GI. For example, a study cited the chapatti made from an amaranth-wheat composite with bottle gourd and tomato curry, which had a favorable GI of 66. Other options include spinach, carrots, and bottle gourd.
Cooking Techniques and Add-Ins
- Slow Cooking: Cooking at lower temperatures for longer can sometimes affect starch structure and glucose release.
- Adding Protein and Fats: Including ingredients like yogurt, paneer, or a small amount of healthy oil can slow down digestion and lower the overall glycemic response of the meal.
Comparison of Roti Glycemic Index Values
| Roti Type | Approximate GI | GI Category | Key Ingredients | Reference |
|---|---|---|---|---|
| Amaranth-Wheat Roti (25:75) | 66 | Medium | Amaranth, Wheat | |
| Amaranth-Wheat Roti (50:50) | 76 | High | Amaranth, Wheat | |
| Whole Wheat Roti | 54 | Low | Whole Wheat | |
| Multigrain Roti (Amaranth, Wheat, Besan) | Lower than 66 | Low-Medium | Amaranth, Wheat, Chickpea Flour | |
| Pure Amaranth Roti | ~107 | High | Pure Amaranth Flour | |
| Barley Roti | 53–66 | Low-Medium | Barley Flour |
Nutritional Benefits of Amaranth Beyond GI
Beyond managing its glycemic impact, amaranth offers significant nutritional benefits that make it a valuable addition to a diet:
- Rich in Fiber: Promotes satiety and digestive health.
- High in Protein: A great source of plant-based protein, making it beneficial for muscle health and weight management.
- Micronutrient Powerhouse: Contains essential minerals like calcium, iron, and magnesium.
- Gluten-Free: Pure amaranth flour is a natural, gluten-free option for those with sensitivities.
Conclusion
To determine what is the GI of amaranth roti, one must consider the ratio of composite flours. While pure amaranth flour has a high GI, a mixed-flour roti, such as one made with a 25% amaranth and 75% wheat ratio, falls within the medium glycemic range. This makes amaranth a versatile and healthy option, especially when combined with other low-GI flours and fiber-rich vegetables. For individuals with blood sugar concerns, opting for a multigrain version is the best approach to harness its impressive nutritional profile while keeping blood glucose levels in check. For specific dietary guidance, it is always recommended to consult a healthcare provider or a registered dietitian.
Glycemic index of grain amaranth, wheat and rice in NIDDM subjects.
