What are Carbohydrates?
The rest of our carbohydrate we get from foods and drinks that contain sugar, including fruit and vegetables, confectionery, sugar, milk and soft drinks. Foods high in refined sugar (table sugar, sugary drinks, confectionery) "empty calories". This means that apart from the energy the sugar provides, there is often very little else of nutritional value. Sugar also contributes to tooth decay and gum disease. Each time sugar enters the mouth, acid is produced by plaque bacteria which can eventually produce a cavity. Frequency of eating sugar has more influence than the amount eaten in total. Frequent consumption of acidic drinks (fruit squashes, fruit juices, fizzy drinks and colas) may cause tooth erosion which is when the surface of the teeth dissolves gradually. Water and milk will not erode teeth, and acidic drinks are best kept to meal times. Because sugars contain calories and no other nutrients, it is sensible for people who are overWeight to cut down on their intake of sugar and sugary foods and drinks.
Good dental health can be maintained by:
1. Brushing twice daily with a fluoride toothpaste.
2. Reducing the frequency of sugar consumption.
Visiting the dentist at least once a year.
The body readily converts alcohol to carbohydrate - each gram provides about seven calories, so also providing "empty calories". This is one of the reasons why alcohol should be limited in a healthy diet.
Most people would benefit from eating a higher proportion of starchy carbohydrate in their daily diet. This tends to result in a diet that is lower in fat, and higher in dietary fibre, especially if whole grain varieties are chosen.
Eating at least five portions of fruit and vegetables each day is also highly recommended. Fruit and vegetables cut the risk of disease, including some cancers and heart disease. In any case, they can be filling, low in calories and high in fibre.
Carbohydrates can be divided into two broad groups: complex or starchy carbohydrates and simple carbohydrates or sugars. All carbohydrates are made up from sugars and each gram of carbohydrate provides 3.75 kcalories.
Simple carbohydrates are made up of single sugars (called monosaccharides) or two sugars joined together (called disaccharides). These sugars are quickly broken down in the mouth and stomach and are absorbed into the blood stream, causing a rapid rise in blood sugar levels. This rapid rise causes the body to produce a sharp rise in insulin levels and results in the sugars being converted into fat.
The rapid rise in blood sugar levels is usually followed by a rapid drop. This means that, although we get a "quick lift", the downside is that simple carbohydrates will very quickly leave us feeling more tired than before. These drops in blood sugar levels can cause dizziness and feelings of hunger and weakness.
Where are they found?
Sucrose is the type of sugar that we put in tea and coffee. It is also found in many cakes, biscuits, pastries, soft drinks and other confectionery products. We have to try to keep these to a minimum in our daily diet. An additional problem with some of these foods is that they also contain a lot of fat so they can be major contributors to increases in body Weight.
Milk and also some fruit and vegetables contain simple sugars - lactose and fructose. In these foods, the sugars are not absorbed rapidly because there are other substances in these foods that prevent this. For example, the sugar in fruit (fructose) forms part of the fruit cell wall and is released slowly when digested.
Complex or starchy carbohydrates
Complex or starchy carbohydrates are molecules that are made up of many sugars joined together. They are an important source of energy. Because the molecules are made up of many sugars, it takes longer for the molecules to be broken down in the stomach. So these sugars are released more slowly into the blood stream, avoiding unwanted peaks in blood sugar levels.
Starchy carbohydrates are the body's favourite fuel. Starch provides most of the glucose our body needs. Glucose is the preferred energy source for muscles and the other tissues and organs of the body. In fact, glucose is the only energy source the brain will use. Because of this it is vital that we have a regular intake of starch in order to help us meet our glucose needs.
Where are they found?
Good sources of starch are bread, oats, pasta, cereals, potatoes, beans, lentils, noodles, rice and fruit.
Many complex carbohydrates cannot be broken down in the stomach into sugars - they are known as fibre. Because of this they cannot be digested and turned into energy.
Fibre is made up of a number of complex carbohydrates. There are two types of fibre: soluble and insoluble. There are no calories, vitamins or minerals in fibre and it is not digested when we eat it. When fibre passes through the bowel it absorbs a lot of water, so it increases the bulk of the waste matter. This also makes the waste softer and increases the speed and ease with which it passes through the bowel.
A diet rich in fibre reduces the risk of a number of bowel problems ie. constipation, haemorrhoids (piles), diverticular disease and cancer of the colon or large bowel. Soluble fibre also helps to stabilise blood sugar levels because it slows down the rate at which glucose is absorbed into the blood stream. It also helps to lower blood cholesterol levels, which is important for reducing the risk of heart disease.
Furthermore the feeling of fullness which fibre produces can help people who are trying to lose Weight to control their appetite.
Where is it found? Fibre is only found in the cell walls of plants. Foods such as meat, fish and dairy products contain no fibre at all. All plant-based foods will contain fibre. Some more so than others. Good sources of fibre are fruit, vegetables, wholegrain rice and pasta, wholemeal bread, many breakfast cereals, nuts, seeds and bran. Particularly good sources of soluble fibre are fruit, vegetables, beans and oats.
In the UK most people eat far too little fibre, on average about 12 grams per day or even less. Ideally, adults should aim for an intake of around 18 grams per day, or a little more. Eating more than 32 grams of fibre per day do not offer any additional health benefits.
Important: if you aim to increase your from a relatively low level, it is best to do it gradually. A sudden increase may produce wind, bloating and stomach cramps, which can be rather uncomfortable for a little while. You will avoid this problem increasing fibre intake gradually.
How much carbohydrate do we need?
The British Nutrition Foundation states that carbohydrates should supply a minimum of 47 % of our total daily calories. Most of this (about 40 %t) should come from starch. The rest (up to 10 %) should come from simple sugars.
This means that if you are eating 2,500 Kcal a day this amounts to a recommended daily intake of at least 313 grams of carbohydrate.
If your daily calorie intake is 2,000 Kcal this amounts to at least 250 grams of carbohydrate per day.
1,500 Kcal a day equates to 188 grams of carbohydrate per day.
All carbohydrates contain 3.75 kcalories per gram.(Source: http://www.bupa.co.uk)