The weight loss experts and diet writers all agree that a large portion of our excess weight comes from the carbohydrates we consume, especially highly refined or processed carbohydrates such as bread, potatoes, pasta, baked goods and other convenient foods. To make the problem worse, few of us exercise enough to avoid the extra pounds.
The basic science behind the low carbohydrate diet is to restrict the intake of foods high in carbohydrates. The Low Carb Diet includes many well-known weight loss programs such as the South Beach, Atkins, Zone, and Carbohydrate Addict diets.
One of the food groups that the body needs to survive are carbohydrates. Carbohydrates, also called carbs, are of two types: sugars and starches. Sugars are simple carbohydrates with a generally sweet taste like cookies and candy and easy to digest. Whereas starches are complex carbohydrates found in pasta, bread, noodles and rice and take longer time to digest.
The body turns all of these digestible carbohydrates into glucose, the sugar that our cells use for fuel or energy. When glucose molecules move from the intestine into the bloodstream, the pancreas releases insulin, a hormone that mobilizes cells to absorb it. Muscles, fats, and other cells then take up surplus glucose from the blood, returning the insulin levels to normal.
After a meal with a high glycemic index (classification of foods according to the rate at which their sugars are released into the blood), blood sugar levels rise and rise rapidly. The insulin needed to fill all that sugar in muscles and fat cells also weakens the activity of glucagon, a hormone that signals the body to burn stored fuel when blood sugar drops below a certain point. The glucose level starts dropping so low, leaving the body hungry for energy. The brain and intestine then send signals of hunger. New cravings are created that requires more carbohydrate intake. We then eat too much which results in more fat, increased insulin levels in the blood, more hunger and more weight gain and the cycle continues.
On the other hand, sticking to a low carbohydrate diet ends this cycle. The reduction in carbohydrates would mean decrease in the insulin levels, increase in glucagon levels, weight loss, improvement in triglycerides (fats carried in the blood which are essential but which, when in excess can lead to coronary damage), a decrease in LDL (bad cholesterol), an increase in HDL (good cholesterol).