All About Carbohydrates
So are carbohydrates good for you or bad for you? It can be a bit confusing as different people say different things about carbs.
Here is some information about carbs that might help you.
What Are Carbs?
Carbohydrates are a source of energy. When eaten, the body converts most carbohydrates into glucose (sugar), which is used to fuel cells such as those of the brain and muscles.
Carbohydrates are one of three macronutrients (nutrients that form a large part of our diet) found in food – the others being fat and protein. Hardly any foods contain only one nutrient and most are a combination of carbohydrates, fats and proteins in varying amounts.
There are three different types of carbohydrate:
Sugar – this is found naturally in some foods, including fruit, honey, fruit juices, milk (lactose) and vegetables. Other forms of sugar (for example table sugar) can be added to food and drink such as sweets, chocolates, biscuits and soft drinks during manufacture, or added when cooking or baking at home. Remember: sugar is a carbohydrate but not all carbs are sugars.
Starch – this type of carb is made up of many sugar units bonded together, is found in foods that come from plants. Starchy foods, such as bread, rice, potatoes and pasta, provide a slow and steady release of energy throughout the day.
Fibre – this carb is only found in foods that come from plants. Fibre helps keep our bowels healthy and some types of fibre may help lower cholesterol. Research shows diets high in fibre are associated with a lower risk of cardiovascular disease, type 2 diabetes and some cancers. Good sources of fibre include vegetables with skins on, wholegrain bread, wholewheat pasta and pulses (beans and lentils). Read more about fibre here
Why Do We Need Carbs?
Carbs are important to your health for a number of reasons. In a healthy balanced diet they are the body’s main source of energy. High fibre, starchy carbs release sugar into the blood more slowly than sugary foods and drinks.
Carbs should be the body’s main source of energy in a healthy balanced diet, providing about 4kcal (17kJ) per gram. Carbs are broken down into glucose (sugar) before being absorbed into the bloodstream. From there, the glucose enters the body’s cells with the help of insulin. Glucose is used by your body for energy, fuelling all of your activities, whether going for a run or breathing. Unused glucose can be converted to glycogen found in the liver and muscles. If unused, glucose can be converted to fat, for long-term storage of energy.
Vegetables, pulses, wholegrain varieties of starchy foods, and potatoes eaten with their skins on are good sources of fibre. Fibre is an important part of a healthy balanced diet. It can promote good bowel health, reduce the risk of constipation, and some forms of fibre have been shown to reduce cholesterol levels. Many people don’t get enough fibre. On average, most people in the UK get about 14g of fibre a day. We are advised to eat an average of 18g a day.
Carbohydrate contains fewer calories gram for gram than fat, and starchy foods can be a good source of fibre, which means they can be a useful part of a weight loss plan. By replacing fatty, sugary foods and drinks with high-fibre starchy foods, it is more likely you will reduce the number of calories in your diet. Also high fibre foods add bulk to your meal helping you feel full.
Questions Asked About Carbs
Q: Should I cut carbs from my diet to lose weight?
A: No, carbohydrates are the body’s main source of energy. In the absence of carbohydrate, your body will use protein and fat for energy. It may also be hard to get enough fibre, which is important for a healthy digestive system and to prevent constipation. Healthy sources of carbs such as starchy foods, vegetables, fruits, legumes and dairy products are an important source of nutrients such as calcium, iron and B vitamins. Cutting out carbohydrates and replacing those calories with fats and higher fat sources of protein could increase your intake of saturated fat, which can raise the amount of cholesterol in your blood – this could in the long term increase your risk of heart disease.
Q: Don’t protein and fat provide me enough energy?
A: While carbs, fat and protein are all sources of energy in the diet, the amount of energy that each one provides varies:
- carbohydrate provides: about 4kcal (17kJ) per gram
- protein provides: 4kcal (17kJ) per gram
- fat provides: 9kcal (37kJ) per gram
If you consume more calories than you burn from whatever source, carbs, protein or fat, you will gain weight. So cutting out carbs or fat does not necessarily mean cutting out calories if you are replacing them with other foods containing the same amount of calories.
Q: Are carbs more filling than protein?
A: Carbs and protein contain roughly the same number of calories per gram, and fat contains almost twice as many calories per gram as carbs or protein. But other factors influence the sensation of feeling full such as the type and variety of food eaten, eating behaviour and environmental factors, such as portion size and availability of food choices. The sensation of feeling full can also vary from person to person. Among other things, protein-rich foods can help you feel full and we should have some meat, fish, eggs, beans and dairy products as part of a healthy balanced diet. But we shouldn’t eat too much of these foods. Remember that starchy foods should make up about a third of the food we eat and we all need to be eating more fruit and vegetables.
Q: How much carbs should I be eating?
A: A third of your diet should be made up of starchy foods, such as bread, rice, potatoes and pasta, and another third should be fruit and vegetables. This means that about half of your daily calorie intake should come from starchy foods, fruit and vegetables. Most of us should also be eating more fibre and starchy foods and fewer sweets, chocolates, biscuits, pastries and cakes. Try to aim for at least five portions of a variety of fruit and veg a day. Go for wholegrain starchy foods whenever you can and eat potatoes with their skins on.
Q: What type of carbs should I be eating?
A: Sweets, chocolates, biscuits, cakes and soft drinks with added sugar are usually high in sugar and calories, which can contribute to weight gain if you eat them too often, while providing few other nutrients. Fruit, vegetables, pulses and starchy foods (especially wholegrain varieties) provide a wider range of nutrients (such as vitamins and minerals) which can benefit our health. The fibre in these foods can help to keep your bowels healthy and adds bulk to your meal helping you to feel full. Cutting out a whole food group (such as starchy foods) as some diets recommend could put your health at risk because as well as cutting out the body’s main source of energy you’d be cutting back essential nutrients like B vitamins, zinc and iron from your diet.
Q: How can I increase my fibre intake?
A: To increase the amount of fibre in your diet, go for wholegrain varieties of starchy foods and eat potatoes with skins on. Try to aim for an average intake of 18-20g of fibre a day.
Here are some examples of the typical fibre content in some common foods:
- two breakfast wheat biscuits (approx. 37.5g) – 3.6g of fibre
- one slice of wholemeal bread – 1.8g (one slice of white bread – 0.7g)
- 230g serving of cooked wholewheat pasta – 10.1g (230g of cooked white pasta – 3.5g)
- one medium (180g) baked potato (with skin) – 4.9g
- 200g of baked beans – 7.4g
- 1 medium orange – 2.7g
- 1 medium banana – 1.1g
Q: Can eating low GI foods help me lose weight?
A: The glycaemic index (GI) is a rating system for foods containing carbohydrates. It shows how quickly each food affects glucose (sugar) levels in your blood, when that food is eaten on its own. Some low GI foods, such as wholegrain foods, fruit, vegetables, beans and lentils are foods we should eat as part of a healthy balanced diet. However, using GI to decide whether foods or a combination of foods are healthy or can help with weight reduction can be misleading.
Q: Do carbs make you fat?
A: Any food can be fattening if you overeat. It doesn’t seem to matter a whole lot whether your diet is high in fat or carbs, but how much you eat in total. In fact, gram for gram, carbohydrate contains fewer than half the calories of fat. Wholegrain varieties of starchy foods and potatoes eaten with their skins on are good sources of fibre. Foods high in fibre add bulk to your meal and help you to feel full. To maintain a healthy weight, we are advised to cut down on sugary foods in favour of fruit, vegetables, pulses, wholegrain starchy foods and potatoes with skins on, while still keeping a watchful eye on portion size.
Q: Can cutting out wheat make me lose weight?
A: Some people point to bread and other wheat-based foods as the main culprit for their weight gain. Wheat is found in a wide range of foods, from bread, pasta and pizza, to cereals and many other foods. However, there is no evidence that wheat is more likely to cause weight gain than any other food. The point is if you consume more calories than your body needs, you will put on weight, regardless of the type of food you eat.
Q: How do carbs affect exercise?
A: Carbohydrates, fat and protein all provide energy, but exercising muscles rely on carbohydrates as their main source of fuel. However, muscles have limited carb stores (glycogen) and they need to be topped up regularly to keep your energy up. A diet low in carbs can lead to a lack of energy during exercise, early fatigue and delayed recovery. Fat and protein are harder to turn into energy than carbs, which means you may feel low on energy during your exercise session.
Q: When is the best time of day to eat carbs?
A: When you should eat carbohydrates particularly for weight loss is the subject of much debate, but there’s little scientific evidence that one time is better than any other. You should have some starchy carbs in appropriate portions with most meals, choosing high-fibre varieties whenever you can.