It seems that every week there is a new headline screaming the pros or cons of carbohydrates. Should we, shouldn’t we? Dietary guidelines suggest that we should get about half of our calories from carbohydrates. On the other hand, some claim that carbohydrates cause obesity and type 2 diabetes, and that most people should be avoiding them. There are good arguments on both sides, and it appears that carbohydrate requirements depend largely on the individual. Some people do better with a low carbohydrate intake, while others do very well eating plenty.
The main purpose of carbohydrates in our diet is to provide us with energy. Most carbohydrates get broken down or transformed into glucose, which can be used as energy. Carbohydrates can also be turned into fat (stored energy) for later use.
Fibre is an exception. It does not provide energy directly, humans cannot digest fibre but it does feed the friendly bacteria in our digestive system. These bacteria can use the fibre to produce fatty acids that some of our cells can use as energy.
Not all carbohydrates are created equal.
There are many different types of carbohydrate-containing foods, and they vary greatly in their health effects. Whole carbohydrates are unprocessed and contain the fibre found naturally in food, while refined carbohydrates have been processed and had the natural fibre removed. Good examples of whole carbs include vegetables, potatoes, fruits, legumes and whole grains. These foods are generally healthy.
Refined carbs include sugar-sweetened snacks, fruit juices, pastries, white bread, white pasta, white rice and others. Many studies show that refined carbohydrate consumption is associated with health problems like obesity and type 2 diabetes. They tend to cause a large spike in blood sugar levels, which then leads to a crash that can trigger cravings for more high-carbohydrate food. This is the “blood sugar roller coaster” that many people are familiar with. Ever eaten a biscuit and found yourself halfway through the packet? Refined carbohydrate foods are usually also lacking in essential nutrients.
Many studies on high fibre carbohydrates show that eating them lowers your risk of disease and can improve your metabolic health. Whole carbs do not cause the same spike to your blood sugar levels.
There are many, of course, who choose to follow a low-carb diet for weight loss reasons and this type of diet is much more effective than the ‘low fat’ diets that were previously recommended by health experts. For people with type 2 diabetes or obesity issues then a low carb diet can work miracles. These types of diets restrict carbohydrates, while allowing plenty of protein and fat.
Carbohydrates are not an essential nutrient. However, many carb-rich plant foods are packed with beneficial nutrients, so excluding them is a bad idea.
Good carbohydrates include
Vegetables (all of them), whole fruits, legumes, whole grains, potatoes, nuts, seeds. People who are trying to restrict carbs should be careful with whole grains, legumes, potatoes and high sugar fruit.
Bad carbohydrates include
Fizzy, sugary drinks, fruit juices, white bread, biscuits, cakes, pastries, ice cream, sweets and chocolate (dark 70% plus chocolate in moderation is fine), crisps and any fried potato snacks.
Sadly, there is no one diet that suits us all. If you are a healthy person trying to stay healthy, then there is probably no reason for you to avoid carbohydrates, just eat whole unprocessed foods as much as possible.
If you are naturally lean and/or highly physically active, then you may even perform better with plenty of carbohydrate in your diet!