By Hannah Ng’uni
In today’s post and subsequent posts, we will take a closer look at what healthy eating is and what makes up a balanced diet one food group at a time. The Eatwell Guide (Gov.uk, 2016) will be just that, our guide to achieving that balance daily. The focus is on the nutrients we get from these food groups and their role in the body.
If you have any medical conditions, please seek advice from your GP before making any dietary changes.
Carbohydrates – the basics
Unfortunately, there are so many myths about carbohydrates, some have led to people cutting out the whole food group from the diet however it is important to understand that it is a combination of the portion size, frequency, type of carbohydrate and the food you combine your carbohydrate with that makes a difference. It would take more than one post to explain carbohydrates in great detail so here are basics.
There are two main types of carbohydrates: simple sugars and complex carbohydrates (starch and dietary fibre).
Simple carbohydrates consist of single ‘sugar’ molecules like those naturally occurring in fruits, vegetables and double ‘sugar’ molecules i.e. table sugar, honey, milk and dairy products. Products such as syrup, jams, sweets, fruit juices, fizzy drinks, biscuits, chocolate, cake are classed as ‘free sugars’ (added sugars) within this group.
In 2015 the Government’s guidelines on sugar changed significantly to push a reduction in intake of ‘free sugars’ due to health risks associated with high levels of consumption.
Complex carbohydrates structurally are made of many ‘sugar’ molecules some linked in straight chains and others branch off, this affects how they are digested and absorbed in the body. Starch is a complex carbohydrate stored in plants, sources include grains (wheat, rice, corn, oats, millet, barley), legumes (peas, beans lentils), potatoes, yams, cassava etc. Most starches are easily digested in the body.
Dietary fibre, however, does not get digested but can be partially broken down in the large intestine then absorbed to provide energy to the body. There are various types of dietary fibres defined by how they present in plant cells walls and the structure of the sugar’ (glucose) units – like starches. Food sources include wholegrains, rolled oats, legumes, lentils, nuts and seeds, fruits and vegetables.
Why eat carbohydrates?
During digestion, carbohydrates are broken down into glucose which is a body’s source of fuel for energy. Most cells in the body, the brain, red blood cells and nervous system rely on glucose for fuel. Some glucose is stored in the liver to regular blood levels, some is stored in the muscle and used to fuel muscle activity. If the body is not getting carbohydrates, fats and/or proteins will be converted to glucose to supply energy and meet the demands of the brain cells and red bloods cells that need a constant supply of energy.
Fibre remains undigested until it reaches the large intestine where it is partially broken down (fermented) by resident bacteria and is still used for energy. Fibre is seen to be beneficial for promoting a healthy gut and immune system. Fibre also helps to reduce constipation, lower cholesterol levels and help regulate blood glucose levels.
It Is important to include a variety of fibre foods in your diet to benefit from the different roles in the body. Should you wish to increase your fibre intake, be sure to also increase your fluid intake.
The current recommendation for fibre intake in adults is 30g and this can be achieved daily by having 5 a day (mixture of fruits and vegetables), including wholegrain foods or starchy options to meals and choosing high fibre snacks instead of high fat/sugar foods. Aim for 3-4 portions of carbohydrate-containing foods a day.
Carbohydrates are not the enemy and remain a key component of a healthy balanced diet. Remember, it is the portion size, type of carbohydrate, frequency of intake and the type of food you mix your carbohydrate with that will have the biggest impact on your nutritional intake. It is advisable to consult your GP if you have a medical condition before making changes to your diet.
British Dietetic Association (2021) Fibre: Food Fact Sheet. https://www.bda.uk.com/resource/fibre.html