March “Eat Healthy” – Carbs: which ones and how many?

In the average western diet we eat carbs all day every day…bread, croissants, cereals, sandwiches, pastries, cakes, biscuits….. and many experts believe we eat too many and the wrong kind .(http://www.huffingtonpost.com/riva-greenberg/carbs-fat_b_2885211.html).

So what are carbs? Carbs are carbohydrate containing foods and they are found in a broad variety of foods from grains and cereals such as flour, bread, pasta, rice, breakfast cereals as well as in food groups such as alcohol, fruit, vegetables and dairy products. Many processed and manufactured foods are carbohydrate heavy such as biscuits and cakes. For more information visit http://www.nhs.uk/Livewell/loseweight/Pages/the-truth-about-carbs.aspx.

So the focus of this article is on understanding more about carbohydrates.

  • Choose root vegetables and whole grains (Wholemeal bread, pasta and rice) instead of refined carbohydrates and grains (white bread, pasta and rice):  Eat sparingly.

What exactly are carbs and what do they do? The US National Library of Medicines gives this explanation “Carbohydrates are one of the main types of nutrients. They are the most important source of energy for your body” (https://www.nlm.nih.gov/medlineplus/carbohydrates.html). So we need carbs for energy. That’s great. And the governement recommends that as much as 45-50% of our daily calories come from carbs. So what is all the fuss about different types of carbs and why should we choose root vegetables and wholegrains and eat other carbs sparingly? What are wholegrains? What are the refined carbohydrates they refer to? At Kalila we like answers so we have done a bit of investigative work into carbs for you and this is what we have found….

Carbohydrates = sugar

Carbohydrates break down into dietary sugars known as glucose which the body requires for energy. After a meal some glucose is used immediately for energy and some is converted and stored in the liver and muscle. Any excess glucose, once the liver stores are full, is converted into fat and stored in tissue. Eating a diet high in carbohydrates and additional sugars may promote weight gain* (https://www.diabeteshealth.com/why-eating-too-many-carbs-makes-you-fat/).

carbs - fat-weight gain

Carbohydrates = ranked according to effect on blood sugar levels

Carbohydrate-containing foods are ranked based on the overall effect on blood glucose levels and this ranking is called the Glycaemic Index (GI). Slowly absorbed foods have a low GI rating, while foods that are more quickly absorbed have a higher rating (https://www.diabetes.org.uk/Guide-to-diabetes/Managing-your-diabetes/Glycaemic-Index-GI/)

There are two types of Carbohydrate: simple (high GI) and complex (low GI)

Simple Carbohydrates – High GI* Complex Carbohydrates – low GI*
 simple-carbs  whole grain carbohydrates

Simple (or refined) Carbohydates = manufactured products, white breads, flours, pasta, confectionary

Simple carbohydrates are small chains of sugars found in refined manufactured products such as sweets, biscuits, jams, milk chocolate and white breads, rice, pasta, and sweet fruits such as banana. They are quickly digested and release glucose into the blood. This fast release of glucose provides energy but also creates a rise in blood-glucose levels (see graph below). As the level then decreases it can fall below the ideal level and lead to sugar cravings.

Simple-Carbohydrates

Complex (or Whole grain) Carbohydrates = brown breads, flours, pasta, root vegetables

Complex carbohydrates are long chains of sugars more commonly found in wholemeal breads, pasta, and rice, and in beans, pulses, and root vegetables. They are digested slowly and release glucose more evenly into the blood. This provides more constant energy and supports balanced blood-glucose levels. Complex carbohydrates typically contain more fibre which also helps slows the release of glucose into the blood and helps us to feel fuller for longer as well as helping our bowels.

complex carbs

 

Too many carbs = too much glucose = converted to fat

Carbs_fat gain

So how on earth to begin to decipher this? The government guidelines advise eating 45-50% of our daily calories from carbohydrates but the evidence suggest that carbohydrates contribute to our overall sugar intake and that this ultimately can be converted into fat. Harvard claim that it is not the overall intake of carbs that is important but the type of carbs we choose (http://www.hsph.harvard.edu/nutritionsource/carbohydrates/). They give the following advice:

  • “The healthiest sources of carbohydrates—unprocessed or minimally processed whole grains, vegetables, fruits and beans (low GI) —promote good health by delivering vitamins, minerals, fibre, and a host of important nutrients.
  • Unhealthier sources of carbohydrates include white bread, pastries, sodas, and other highly processed or refined foods.  These items contain easily digested carbohydrates (high GI) that may contribute to weight gain, interfere with weight loss, and promote diabetes and heart disease.

Putting the pieces of the puzzle together… we need carbs for energy….our body breaks it down into glucose….but too many carbs and the glucose (if not used up in physical activity) gets converted to fat. There are different types of carbs….simple and complex….and these sugars break down fast or slow to give us energy. So it’s a bit like sprinting or running a marathon? The simple carbs seem to be white eg. white breads and pasta and processed foods and they are the sprinters which give us a quick burst of energy followed by a sugar craving. The complex carbs seem to be brown eg. brown breads and pasta and wholemeal foods and they are the marathon runners and keep us going for longer. An added bonus is they also contain more fibre, which we’ll look at in more detail in one of the upcoming articles. More technically, these foods have a GI ranking which tell us how much they affect our blood sugar levels.

slow fast

So what does this mean for our series on “Eat Healthy” and how does this information affect out food choices? Knowing a little bit more about the differences in carbohydrates may influence which we choose next time we go shopping or open the fridge to start cooking dinner. No doubt many family favourites can be made using complex carbs or rather wholemeal ingredients to give us that slower energy release.

Want to know more?

Here is a link to a carbohydrate fact sheet from The Association of UK Dieticians.

*https://www.bda.uk.com/foodfacts/Carbs.pdf

 

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