Carbohydrates might be the most discussed macro nutrient, being portrayed as the root of all evil or the best thing since (and including) sliced bread.
What are they?
Carbohydrates are organic molecules typically classified according to their structure. And, structurally speaking, there are two types of carbohydrates: simple and complex.
Simple carbohydrates are smaller, more easily processed molecules known as mono- and disaccharides since they contain either one sugar molecule or two sugar molecules linked together.
Complex carbohydrates, on the other hand, are called polysaccharides since they have more than two sugar groups linked together.
Monosaccharides are the simplest form of carbohydrate and cannot be broken down any further since they contain only a single sugar group. Oligosaccharides consist of short chains (di-, tri-, etc) of monosaccharide units all put together. And polysaccharides are long chains of monosaccharide units all put together.
Why do we need them?
Carbohydrate consumption can alter energy dynamics and disease progression in the body and they are primarily a source of immediate energy for all of your body’s cells.
All carbohydrates we consume are digested into monosaccharides or simple sugars before they are absorbed by the body, regardless of whether the food source is a simple sugar cube or a high-fibre, low glycemic index bowl of oatmeal. It is just that the healthier carbs are digested and absorbed much slower while the non-healthy carbs are digested very quickly.
Once broken down and absorbed, these monosaccharides/sugars go to the liver to fill energy stores. After that, they enter the bloodstream and venture out to the other cells of the body. This is when insulin is released to handle this sugar load on the body. Larger insulin response can be beneficial at certain times (like after an intense workout) and not so beneficial at certain times (like before bed).
When the diet consists of simple sugars and refined carbohydrates (which the body breaks down rapidly), one may notice elevations in blood triglyceride levels, bad cholesterol, and insulin resistance.
Carbohydrates that are digested and absorbed slowly, such as whole grains, fruits, and vegetables, can help to control insulin response, energy levels, and body composition. Such unrefined, unprocessed, complex carbohydrate sources may reduce triglycerides and improve ones cholesterol profile (Jenkins et al 1987). Other benefits of a lower glycemic diet include increased vitamin and mineral intake, increased fibre intake, enhanced satiety, a higher thermic effect of feeding, and blood sugar control.
(Ludwig & Eckel 2002; Ludwig 2000).
So what should we eat?
- Most of us know what the good carbs are: plant foods that deliver fibre, vitamins, minerals, and phytochemicals along with grams of carbohydrate, such as whole grains, beans, vegetables, and fruits.
- Added sugars
- Refined white grains
There is no way to sugarcoat the truth: Canadians are eating more sugar than ever before. In fact, the average adult takes in about 20 teaspoons of added sugar every day, most of it hidden in processed foods.
The Potentially Ugly aka the problems with not eating carbs
- As a weight loss strategy, cutting carbs (while reducing the total number of calories) clearly works pretty well for some people. If it did not, Atkins would have never been popular.
Here is the thing: most of us require some level of carbohydrates to function at our best over the long term. Sure, we can cut carbs temporarily if we need to lose weight quickly. But for most of us keeping carbs too low for too long can have disastrous consequences. This is especially true for those of us who workout, if you like to exercise regularly and enthusiastically, restricting your carb intake too drastically can lead to decreased thyroid output, increased cortisol output, decreased testosterone, impaired mood and cognitive function, muscle catabolism and suppressed immune function.
In other words: Your metabolism might slow, your stress hormones go up and your muscle-building hormones go down. You feel lousy, spaced-out, sluggish, cranky and maybe even sick. Most vexing of all: You probably do not even lose that much weight in the long term. Definitely not what most of us want!
At the end of the day, we can reap the health benefits of good carbs by choosing carbohydrates full of fibre, these carbs get absorbed slowly into our systems, avoiding spikes in blood sugar levels. Examples: whole grains, vegetables, fruits, and beans. We can minimize the health risk of bad carbs by eating fewer refined and processed carbohydrates that strip away beneficial fibre. Examples: Sugar, white bread, white rice.
(References: R.Andrews, PN,all about carbohydrates)