The low glycemic diet is based on the concept of the glycemic index (GI). Studies have shown that the low GI diet tends to result in weight loss, reduce blood sugar levels, and may lower the risk of heart disease and type 2 diabetes. However, some nutritionists are of the opinion that it may not be clear in reflecting the overall healthiness of foods based on the way it ranks foods. This article discusses the concept behind the glycemic diet, its benefits and possible drawbacks.
What is the glycemic index (GI)?
The glycemic index (GI) is a measurement system that ranks foods according to the effects they have on your blood sugar levels. It was created in the early 1980s by Dr. David Jenkins, a Canadian professor. The rates at which different foods raise blood sugar levels are ranked in comparison with the absorption of 50 grams of pure glucose. Pure glucose is used as a reference food and has a GI value of 100.
The three GI ratings are:
- Low: 55 or fewer
- Medium: 56–69
- High: 70 or more
Foods with a low GI value are always recommended as the preferred choice. These foods are slowly digested and absorbed, thereby resulting in a slower and smaller rise in blood sugar levels. On the other hand, foods with a high GI value should be limited. Since they are quickly digested and absorbed, it results in a rapid rise and fall of blood sugar levels. It’s important to note that foods are only assigned a GI value if they contain carbs. Hence, foods without carbs won’t be found on GI lists. Examples of these foods include beef, chicken, fish, eggs, herbs, spices and their likes.
The low GI diet is typically associated with helping those who have been diagnosed with diabetes; however, following this diet can be beneficial to the overall health of anyone. Usually, the goal is to stabilize blood sugar levels within the body to optimize the body’s response to glucose, which in return will increase fat burning and help overall disease risk. One of the pros of the glycemic diet is that when you take calorie counting out of the equation and focus on the quality of your foods and specifically the glycemic load, it is easier to follow and enjoy what you eat. The fact that a portion of food has a low glycemic index, does not necessarily mean it is healthy. The glycemic index is only one component of what makes a food a healthier choice.
Factors that affect the GI of a food
The GI of a food or meal is influenced by a number of factors, including the type of sugar it contains, the structure of the starch, the cooking method, and the level of ripeness.
- Type of sugar: there’s a misconception that all sugars have a high GI. The GI of sugar ranges from as low as 23 for fructose to up to 105 for maltose. Therefore, the GI of food partly depends on the type of sugar it contains.
- The structure of the starch: starch as a carbohydrate comprises of two molecules; amylose and amylopectin. Amylose is difficult to digest, whereas amylopectin is easily digested. Foods with a higher amylose content will have a lower GI.
- How refined the carb is: certain processing methods like grinding and rolling disrupt amylose and amylopectin molecules, raising the GI. Consequently, the more processed a food is the higher its GI.
- Nutrient composition: adding protein or fat to a meal can slow digestion and help reduce the glycemic response to a meal.
- Cooking method: preparation and cooking techniques also have effects on the GI. Generally, the longer a food is cooked, the faster its sugars will be digested and absorbed, raising the GI.
- Ripeness: the complex carbs contained in unripe fruits break down into sugars as the fruit ripens. The riper the fruit, the higher its GI. For example, an unripe banana has a GI of 30, whereas an overripe banana has a GI of 48.
Benefits associated with Low Glycemic Diets
Eating lower-GI foods can definitely be beneficial for many people — particularly because many of the foods that are lower glycemic index also tend to be higher in protein and/or fibre, as well as higher in nutrients. The following are the major benefits associated with the low GI:
- Low GI diets have been associated with a reduction in weight and cholesterol: on the other hand, high GI diets have been linked to heart disease and an increased risk of certain cancers.
- Improved cholesterol levels: Studies have shown that low GI diets reduce total cholesterol by 9.6% and LDL (bad) cholesterol by 8.6%. LDL cholesterol is also associated with an increased risk of heart disease and stroke.
- Weight loss: research suggests that low GI diets can promote fat loss. One study showed that people on a low-glycemic diet lost more fat than those on a high-glycemic diet with the same calories. Overall, the scientific evidence is mixed and unable to show consistent findings.
- May reduce the risk of cancer: some studies suggest that people who consume high GI diets are more likely to develop certain types of cancer, including endometrial, colorectal, and breast cancer, compared with people on low GI diets.
- Sticking to a low glycemic index diet may help prevent conditions like diabetes and heart disease: the low GI diet appears to reduce blood sugar levels in people with diabetes. Recent research has strongly associated high GI and GL diets with an increased risk of heart disease. The glycemic index diet was developed to help people with diabetes manage their blood sugar, and that’s what it’s best for. For those with diabetes or prediabetes, this diet is an important piece in the big picture of taking charge of the food you eat and staying healthy and active.
Drawbacks of the low GI diet
Although the low GI diet has several benefits, it also has a number of drawbacks. The GI doesn’t provide a complete nutritional picture. It’s important to also consider the fat, protein, sugar, and fiber contents of a specific food, regardless of its GI. Another drawback is that the GI measures the effect of a single food on blood sugar levels. However, most foods are consumed as part of a larger mixed meal, making the GI difficult to predict in these circumstances. Lastly, as earlier stated, the GI doesn’t take into account the number of carbs you eat. However, this is an important factor in determining their effect on your blood sugar levels.
Just like any other diet, a low-GI diet should not be considered as a solution to underlying health issues linked with nutrition. It is a commitment to choosing certain foods that may help prevent conditions like diabetes or heart disease. Following a low-GI diet requires dedication, but it is definitely possible with a bit of planning and supervision. Like earlier discussed, cooking methods and the combination of other foods at a meal can change the GI of a food. Adding a little healthy fat, like olive oil or avocado, can lower the GI, while cooking or blending a food may increase the GI. If you are considering the glycemic diet, you can further consult a medical practitioner to be well-balanced.