Low Gi & Low-cal Diet Foods

Foods that have a low glycemic index, and are low in calories are excellent choices for a diet. The glycemic index measures how fast a food raises your blood sugar. Many nutritionists, particularly those who advocate low-carbohydrate diets, believe blood sugar elevations are a primary cause of body fat. Calories also cause weight gain. You gain 1 lb. when you eat 3,500 calories more than you lose via daily life.

Explanations

The glycemic index was formulated in the 1980s by a team of Canadian nutrition scientists led by David Jenkins, according to a 2002 report by the "Harvard Heart Letter." Jenkins gave glucose, a simple sugar, a 100 score his index. A food that had half glucose's effect on blood sugar got a 50 score. Calories are a measurement of energy. A gram of fat in a food has 9 calories, while 1g of carbohydrates or protein has 4 calories.

Definitions

Foods with a glycemic index score of 55 or lower are considered low-GI foods, according to "Carbohydrates: Good Carbs Guide the Way," a Harvard School of Public Health report. Foods with a significant amount of fat and protein are always low-GI foods unless they also have a lot of carbohydrates because fats and protein cause little or no blood-sugar elevation, according to "Dr. Atkins' New Diet Revolution." Foods with 40 calories or fewer are considered low-calorie foods.

Features

Foods that are low-GI foods and low-calorie foods almost always have low amounts of fat and digestible carbohydrates. Fiber is the primary indigestible carbohydrate. Many fruits and vegetables have low GI scores because they have a lot of fiber, but few digestible carbohydrates. Many beans, breads, cereals, pastas and rice have high GI scores because they have many digestible carbohydrates. Meat, poultry, fish, eggs and cheese are low in all carbohydrates, but are often high in calories because they have a lot of fat.

Statistics

Many vegetables have a glycemic index score below 20, well below the 55 standard to be a low-GI food, and fewer than 40 calories per serving. They include mushrooms, kale, squash, okra, eggplant, cabbage, turnips, cauliflower, cucumbers, broccoli and celery. Fruits with a GI score 55 or below and fewer than 40 calories per serving include grapefruit, apricots, peaches, pears, plums and strawberries.

Discovery

Nutritionists believed that simple carbohydrates, such as sugar and white flour, caused much faster blood sugar hikes than complex carbohydrates before the glycemic index was formulated. However, the Canadian scientists discovered that many complex carbohydrates, such as cereal and potatoes, also caused rapid blood sugar elevations, reported Atkins. Potatoes have an 85 glycemic index score. Other fruits and vegetables with high GI scores include carrots, peas, corn, bananas, pineapples and watermelon.