Posts Tagged ‘low carb’

Glycemic Index & Picking the Right Carbs

GLYCEMIC INDEX & PICKING THE RIGHT CARBS

Don’t be afraid to eat carbs!! Carbs/Carbohydrates (more specifically, the glucose found in carbohydrates) are your brain’s primary source of fuel and your body’s energy supply during high intensity exercise. If you are trying to lower your body’s fat composition, focus on eating carbohydrates that have a low glycemic index, rather than severely cutting or completely eliminating carbohydrates from your diet.

What is glycemic index?

Glycemic index measures a carbohydrate food’s ability to raise blood glucose levels. When we consume carbohydrates, they get digested and influence our blood sugar levels. Some carbohydrates raise blood glucose levels a lot, while other carbohydrates affect blood glucose minimally.

How may the glycemic index help you lose fat?

By keeping blood glucose levels low, you can better manage your insulin response to food. Insulin is a powerful hormone that can deposit fat. Therefore if you are trying to lower your body’s fat composition, you want to keep it under control!

How can you lower the glycemic index of a food?

You can’t actually lower the glycemic index of a food, but there are other foods that can be paired with high glycemic index foods that will slow the release of glucose into the blood and help keep insulin levels under control. By pairing fat and/or fiber with a high glycemic index food, the glycemic index may be lowered. The addition of fat and/or fiber slows the speed at which food leaves your stomach. This therefore slows the release of glucose into the blood stream, keeping insulin levels under control.

What are some foods that have a low glycemic index?

– 100% stone ground whole wheat bread

– oatmeal, oat bran, barley

– sweet potato, yam

– corn, carrots, peas

– legumes, lentils

– most fruit (except bananas, pineapple, & melons just to name a few)

Bottom line…

Don’t completely eliminate carbohydrates from you diet! They are an important component to a healthy diet, proper brain function, and your performance during exercise.

Low Carbohydrate and/or Low Grain diets: YES or NO?

What is a low carbohydrate (CHO) diet?

             A low CHO diet is when <30% of the total required energy intake is from CHO. This typically means that those calories that are not consumed as CHO, are compensated by consuming more    protein and/or fat. 

What happens metabolically when you reduce CHO intake?

           Reducing your CHO intake leads to a decrease in GLYCOLYSIS (production of usable energy from glucose, or CHO) and an increase in GLUCONEOGENESIS (the process of creating glucose from non- CHO sources). Gluconeogenesis is increased in order to maintain blood glucose to prevent HYPOGLYCEMIA, and to maintain vital organ and tissue function that require glucose for energy, such as the brain.  * This is not a complete overview of what happens metabolically from reduced CHO intake!!

What does it mean for exercise?

          Regardless of the intensity of the exercise, CHO is a major and necessary substrate for energy production. This means that if CHO is not available, exercise performance could be substantially diminished. Additionally, since CHO is used to synthesize serotonin, reduced intake could lead to less serotonin and may contribute to mood alterations, anxiety, anger, and depression.

Many micronutrients such as vitamins and minerals, are obtained via the foods that are rich in CHO. Reducing CHO to <30% of total energy intake could potentially lead to a deficiency in those micronutrients if not compensated with other foods in the diet.

***Be sure to ask a professional such as a registered dietician before going on any diet. Keep in mind that all diets are not meant for weight-loss. It may be possible to do certain diets successfully and safely, but make sure to carefully decide (with profession consultation) if the benefits out-weigh the risks!

~Written by Fitness Staff member, Amy Bloemendal

Reference:

Frigolet M, Barragan VR, Gonzalez MT: Low– Carbohydrate Diets: A Matter of Love or Hate. Ann Nutr Metab 2011; 58:320-334.