Low Glycemic Index Diet (GI Diet)

The "glycemic index diet" or "GI diet" or "low glycemic diet" are more of a way of eating rather than a diet. Originally developed as a tool to help diabetics manage blood sugar control, the glycemic index has found its way into the mainstream weight loss market. The glycemic index is the basis for many popular diet plans, such as South Beach Diet and the Zone diet.

What is GI (Glycemic Index)?

Not all carbohydrate foods are created equal, in fact they behave quite differently in our bodies. The glycemic index or GI describes this difference by ranking carbohydrate foods according to their effect on our blood glucose levels. Carbohydrates that break down quickly during digestion, releasing glucose rapidly into the bloodstream, have a high GI; carbohydrates that break down more slowly, releasing glucose more gradually into the bloodstream, have a low GI.

Research has shown that very high glucose levels after meals, called glucose spikes, are damaging to our arteries and various blood vessels, and they promote direct increase in insulin levels. The blood sugar spikes of high-GI foods are especially problematic for people with diabetes because their bodies have trouble regulating blood sugar. Eating low-GI foods means you avoid those spikes and dramatic falls in blood-glucose so you get a much steadier stream of energy. You, therefore, reduce your risk of heart disease and other chronic diseases that are implicated by those blood-glucose fluctuations.

What is a GI Diet?

The Low Glycemic Index Diet was developed by Dr. David J. Jenkins, a professor of nutrition at the University of Toronto and later turned into a successful line of diet books by author and former president of the Heart and Stroke Foundation of Ontario, Rick Gallop.

The GI diet is similar to the low carb diet but it is not as strict, and targets the types of carbs rather than the quantity of carbs for each meal. The GI diet works on the premise: the lower the GI of the food, the better. The individual following the GI diet shouldn't feel deprived or hungry between meals.

Unlike other diets, there are no 'forbidden foods'. The key is to try to eat low GI foods more often than high GI foods.

Glucose is set at 100, and all foods are indexed against that number. A high Glycemic index food has a value of 70 and above. A GI value of 56-69 is considered medium and any foods lower than 55 are considered a low Glycemic index food. Foods with a low GI are best as they digest more naturally and help provide a steady supply of energy over the course of several hours, it also makes us feel fuller for longer.

What should I eat?

The basic technique for eating the low GI way is simply a "this for that" approach, ie, swapping high GI carbs for low GI carbs. You don't need to count numbers or do any sort of mental arithmetic to make sure you are eating a healthy, low GI diet.

• Use breakfast cereals based on oats, barley and bran.
• Use unrefined breads as they have higher amounts of fiber and a lower GI value than white breads. However, many brown breads are treated with enzymes to soften the crust, which makes the starch more accessible (high GI).
• Reduce the amount of potatoes you eat.
• Enjoy all other types of fruit and vegetables as they tend to have a low glycemic index and a low glycemic load. This is because they contain very little carbohydrate per serving. This also applies to carrots, which were originally and incorrectly reported as having a high GI.
• Use Basmati or Doongara rice.
• Enjoy pasta or noodles.
• Eat plenty of salad vegetables with a vinaigrette (a mixture of vinegar and oil flavored with herbs and spices) dressing.

Here is a table of some foods along with their glycemic index:

What should I Not eat?

The combination of high fat and high carbohydrate content in foods is a very unhealthy, craving inducing mixture. Be sure to avoid this combination found in foods such as ice cream, French fries, burgers (with bun), doughnuts, croissants and potato chips.

All fats have an extremely low glycemic index but eating excess fat is not necessarily healthy. The best fats for regular consumption are olive oil and flaxseed oil. In particular, olive oil is not only good for salad dressings but also is good for cooking because it does not degrade at high heat. Be sure to keep all oils refrigerated to prevent rancidity.

What are the Advantages of GI Diet?

Benefits of G.I. way of eating are:

• You enjoy tasty foods but limit storage of fat,
• Increased energy level and wellbeing,
• Control of blood sugar,
• Less hunger feelings,
• Less craving for sugary foods,
• Less bloating feeling after meals,
• Ability to eat more food if desired,
• Less risk from diabetes and other diseases,
• No strict calorie reductions.

What are the Disadvantages of GI diet?

The limitations of GI diet are:

• The glycemic index does not take into account other factors such as insulin response, which is measured by the insulin index.
• Some low GI foods are high in saturated fat, salt and calories.
• The glycemic index is significantly altered by the type of food, its ripeness, processing, the length of storage, cooking methods, and its variety.
• It is difficult to identify the GI value of a whole meal.
• The glycemic response is different from one person to another, and even in the same person from day to day, depending on blood glucose levels and insulin resistance.

And finally, a healthy GI diet plan always advises regular exercise. Physical exercise helps to reduce blood sugar in the bloodstream. This is why postprandial exercise is recommended for diabetics.