- What is the “glycemic index”
- The role of different hormones
- Putting it all together
In this article, we will be covering important aspects and facets as to why a low-carb diet is considered, nowadays, a much more healthy diet that promotes weight loss, energetic life and most importantly a long-term healthy life.
We will introduce the concept of glycemic index, different hormones roles, and finish by citing different low-carb diets.
The misconception is that we’ve always thought that a calorie is just a calorie and we only gain weight by eating food items that are high in calories, such as fat.
While this concept looks true, we have obviously missed many other factors that contribute to increasing one’s weight and demoting one’s health.
Science is now showing that the key to a balanced life is the balance between the different hormone secretions and functioning. For every food type (carbohydrates, protein, fats) there are one or more responsible hormone. Each food item has an effect on the production or activity of the equivalent hormones. Now it is more convincing to study the effect of each food type on the hormonal secretion and functionality and how they play a role in one’s diet.
When we eat any form of carbohydrates (including starch and sugars), they are digested and converted into glucose, a simple sugar, by our bodies.
Glucose is then absorbed and therefore enters into the blood stream providing energy for our daily activities.
Glycemic Index (GI) is a measure of how much a specific amount of ingested carbohydrate (usually 50 grams) will cause the person’s blood sugar to rise and remain elevated over time. This value is relative to the effect of pure glucose which is assigned a GI value of 100.
Food with elevated GI index will be quickly absorbed into the blood stream, whereas foods with low GI will be slowly absorbed into the blood stream thus won’t affect the blood glucose level in a fast manner.
Some literature use pure glucose as reference point thus highest GI can be maximum 100, however some use the white bread as the base of GI measurement, thus you can have a GI of maximum of 140.
Foods with GI ranging between 70 or higher are considered High, 55-70 are considered Intermediate, 55 or less are considered Low.
To determine a food’s GI, the food and glucose are consumed on separate days, blood samples are taken under supervised conditions, and the results are measured in a laboratory, this test is repeated with different individuals or repeated many times over a certain number of days.
Another Factor that causes variation in GI is a different variation of the same type of food item. For instance, sweet corn from New Zealand has a GI of 48, while sweet corn from an American grocery store has a GI of 60.
Listed below is a tabulated form of other reasons contributing to the variation of GI:
Other Factors affecting Glycemic Index
|Fiber Content||Fiber, especially soluble fiber, slows down the digestion of starch, therefore high fiber foods have lower glycemic index. For instance, apples with skin have a lower glycemic index than apples without skin.|
|Fat, Protein||Fat and protein slow down foods from leaving the stomach, therefore foods containing fat and protein such as beans and milk have lower glycemic index values.|
|Acid content||Lemon juice, vinegar or lime juice can also lower the glycemic effect of a meal.|
|Maturation||Unripened fruits have lower glycemic index values than ripe fruits.|
|Particle size and natural packaging form||For instance cracked grains produce a lower glycemic index that coarse flour, which in turn produces a lower glycemic index than finely milled flour.
The larger the particle size, the lower the GI.
It is noted that the lowest glycemic indexes are associated with the whole grains.
|Processed food||Studies showed that when a grain is cooked, it becomes gelatinized thus increasing its susceptibility of the starch to enzymatic digestion.
The less the food is processed the lower its GI.
High glycemic index foods include glucose, sugar, honey, pineapple, raisins, ripe bananas, baked/mashed potato, parsnips, carrots, rice, regular bread, Cornflakes, muffins, dates.
Low glycemic index foods include legumes/pulses, beans, whole wheat pasta, barley, whole wheat, apples, dried apricots, peaches, grapefruit, oranges, pears, avocados, leafy green vegetables, tomatoes, broccoli, yogurt, milk and nuts.
Now that we have defined GI, we will now explain the glycemic effect of a meal on the secretion and functioning of different hormones.
There are three general food items: Carbohydrates, Proteins and Fats.
In layman’s terms, carbohydrates are the food items that grow in the grounds, immobile, such as grains, fruits, pasta, bread, etc… whereas protein moves around, mobile, such as animal products (of course many non-animal food items also have protein), and fats in its different forms is found in both animal and vegetable products.
Whenever we eat carbohydrates, our body secretes insulin hormones. Insulin hormone is known as “the storage hormone”, it is produced by the beta-cells of the pancreas. It tells the body to store incoming nutrients in the cells, excess storage will be stored as fat and glycogen for later usage. If there weren’t enough insulin secretion, then our cells would starve to death. Not only excess insulin will make you fat, but will also:
- Increase the aging process
- Prevent the usage of stored fat
- It will tire the pancreas and lead it to overwork
- All excess calories, through the help of insulin will be sent directly to your hips, stomach or other storage areas
- Insulin encourages the storage of all food groups (fats, amino acids, carbohydrates)
- Causes obesity which leads to many diseases such as: coronary artery disease, increased risk of fatal heart attacks, elevated levels of lipids
You don’t have to stop eating high GI foods! But it may be better to eat them with some low GI foods, as part of the same meal.
High GI food can give you so much sugar and potential energy that a lot can be left over to turn to fat.
However, when we eat protein, our body secrets the glucagon hormones. Glucagon hormone is known as “the mobilization hormone”, and is also produced in the pancreas.
As opposed to insulin (which is known as storage hormone), glucagon is the stored nutrients mobilization hormone, it encourages the breaking down of stored fat so that it may be used again as blood glucose.
Glucagon also plays a role in preventing hypoglycemia (low level of blood sugar), whenever the blood sugar level is too low, the pancreas will release glucagon which will break stored glycogen into glucose.
Whenever blood sugar level is low (not enough insulin) the glucagon is present, and when the insulin is present the glucagon is absent. Both play a complementary role for balancing the blood sugar level.
In short, glucagon is responsible for:
- Preventing hypoglycemia
- Breaking down of glycogen and stored fat to be used as glucose (main source of energy)
- Gluconeogenesis, which is the conversion of muscle protein into blood glucose
- Facilitating weight loss
By now you may be wondering about the role of fat. Fat have no direct effect on insulin nor on glucagon. Fat has an effect on another group of hormones called eicosanoids, and these hormones also help control insulin levels. The eicosanoids hormones are master hormones, just like a computer, they orchestrate the functions of a wide variety of hormonal systems in the body.
So far we have covered how different hormones affect our system and how different food items affect the hormones, we will now be covering how to use this information in favor of weight loss, health and optimal body functioning.
When a person eats carbohydrates based meal, after digestion and absorption, glucose level will increase. Accordingly, this will trigger insulin release, which will cause the storage of fat. When blood sugar falls too low, glucagon is triggered causing the release of stored fat into glucose, again balancing the blood sugar.
We can see that the overweight person probably has increased insulin production because of excessive stimulation of the pancreas through overeating or genetic tendency towards insulin resistance (originally referred to as Syndrome X in 1988 by Dr. Gerald Reaven).
It is very difficult to lose weight when even low levels of circulating insulin exist.
If a person becomes obese, then he might have high risk of developing insulin resistance. Insulin resistance is a condition of decreased responsiveness to insulin, whereas a larger than usual quantity of insulin is needed to balance the blood sugar level. And as we know already, any increase of insulin level is not healthy.
The question now is, how and what to eat to prevent high insulin secretion?
The key answer is “Balance”. You need to balance your insulin against your glucagon secretion. This is done by eating a balanced meal that will allow the body to release little insulin and an appropriate counter amount of glucagon hormones.
Many diet systems are devised to provide one with guidelines as what, when and how to eat. Some of them are: “The Zone” and “The Sugar Busters” diets.
Their typical meal is always composed of protein, carbohydrates (preferably low GI) and fats. Studied amounts of these food combination will make sure that you will not suffer any blood sugar level imbalance. These diets also encourage 3 meals and 2 snacks per day to maintain the blood sugar level.
These diets promises the following benefits:
- Looking better: By loosing weight, not necessarily by the scale, but your shape will be transformed from an apple like to a more beautiful shape
- Feeling better: You’ll feel less moody or cranky because you won’t experience those sugar lows that make you tired, hungry and irritable
- Fewer carbohydrates cravings: Once you start eating a balanced low-carb meal, your craving to carbohydrates will start to diminish since your blood sugar level is always constant.
- Permanent fat loss: Since insulin is responsible for storing fats, by balancing insulin secretion in a permanent way through the diet, you will permanently lose weight.
- Reduce risk of heart disease, the development of type 2 diabetes and protection against arthritis and osteoporosis
- Live longer: Since excess insulin will increase aging process
- Health Castle – What is the Glycemic Index (web)
- The new Sugar Busters! Cut Sugar to Trim the Fat (book)
- The 7-day Zone diet (book)
- Nutrition Essentials and Diet Therapy (book)
Last updated: 01/10/2005