Tuesday 19 March 2013

Exploring Carbohydrates

Introduction

I'm going to do a series of blog posts about carbohydrates; what they are and why they are important, how they relate to other sources of energy, their effects on diet and body sculpting and the relative nutritional values of various kinds of carbohydrates.  By which I mean: what are they and which ones are "best"?


What Are Carbohydrates?

The "science": carbs are organic compounds consisting of carbon, hydrogen and oxygen (elements they have in common with protein and fat; protein has an added element of nitrogen and fat has a much higher proportion of carbon to its makeup).


Almost every meal with have some carbohydrate element, but the most accessible form of carbohydrate for us to see are sugars.  There are plenty of other examples of carbohydrates, the more complex types are most commonly found in foods derived from grains (eg flour and rice) and potatoes.  

As part of the digestive process, all carbohydrates are converted to glucose in order to be absorbed by the blood - how quickly we feel hungry is can be related to how quickly our body can convert carbs to glucose, absorb and store the glucose.

Incidentally, dietary fiber is actually an indigestible for of carbohydrate - the bacteria in our gut use them for energy.  Therefore, the energy content of fiber is never included in calorie calculations.

In later posts I'll compare the nutritional values of food sources such as potatoes, rice, bread and pasta.




How Are Carbohydrates Used?

Critically, carbs are the body's preferred source of energy, generally more accessible than fat, being stored in in the muscle that's working and requiring only a short time to be prepared for use as fuel.

Carbs are the brain's only source of energy, although the brain stores its carb reserve in the liver - which the muscles can raid if they need to.  When blood sugar levels get low we get feelings of dizziness and nausea.

Energy Content of Carbohydrates

The nutritional professionals use a few rough and ready numbers for calculating the energy content of food:

  • Protein - 4KCals
  • Fat - 9KCals
  • Alcohol - 7KCal
  • Carbohydrate - 4KCal

Next Time...

I'll compare the energy content of various common kinds of "complex" carbohydrates






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