Sometimes, the foods that we eat can affect the chemicals that are present in our
brain. These chemicals can, in turn, have an affect on the way we think, feel and behave.
The glycemic index (GI)
The glycemic index (GI) is a numerical system that tells you how fast a particular food causes a rise in your
blood sugar levels. A food with a high GI will produce a sudden rush in
blood sugar, while a food with a low GI will keep your
blood sugar levels more stable.
Eating low GI foods will leave you feeling fuller for longer, and will help you to avoid snacking in between meals. Foods that have a low GI include:
- bran cereals, and
However, as well as eating low GI foods, sometimes it is necessary to eat high GI foods. For example, after exercising your muscles need to restore their sugar levels quickly, as most of their energy will have been used up. This is when eating a food with a higher GI value, such as a banana, can be beneficial.
A healthy balanced diet
In the same way that it is important to include foods with low and high GI values in your diet, it is also important to ensure that your diet is balanced and contains foods from all five of the main food groups. The five main food groups are carbohydrates, proteins, fruit and vegetables, dairy, and fats and sugars.
Carbohydrates include starchy foods, such as bread, rice, potatoes, and pasta. Sources of protein include fish, meat, eggs, nuts, and beans. Dairy products, such as cheese, milk, and yogurt are good sources of calcium, and are important for strong bones and teeth.
Fruit and vegetables are rich in vitamins and minerals, which are essential nutrients that your body needs in order to work properly. You should eat at least five portions of a variety of fruit and vegetables a day.
Fats and sugars contain more energy than any other food group and should make up the smallest part of your diet. Fats are divided into two groups - saturated and unsaturated. Eating a small amount of unsaturated fat will help to keep your
immune system healthy and can reduce
Foods that are high in sugar, such as chocolate, cakes, cookies, and carbonated drinks or soft drinks, give your body an instant energy rush when you eat them. However, after the initial rush, your sugar levels will drop. As your sugar levels drop, so will your energy levels. As a result, you may find it more difficult to concentrate, or you may feel irritable, tired, and lethargic. As sugary foods are bad for your teeth and high in calories, you should eat them sparingly, as a special treat.
Vitamins and nutrients
It is important that your body gets enough essential vitamins and nutrients in order for you to stay active. For example, if your body does not get enough iron, it can cause you to have a condition known as anemia. This is where your red
blood cells are unable to carry as much
oxygen as normal to the organs and
tissues in your body. As a result, it can leave you feeling faint, lethargic, and lacking in energy.
Make sure that you eat enough iron-rich foods, such as:
- red meat,
- green, leafy vegetables,
- legumes, and
- fortified breakfast cereals.
Additives are substances which are added to foods to help make them last longer, as well as improving their appearance, taste, and consistency.
If an additive has an E number, it shows it has passed through safety tests and has been approved for use throughout the European Union. Artificial colors in foods are often listed by their E numbers.
There is some evidence to suggest that certain artificial food colors are associated with an increase in
hyperactivity in children. If a child shows signs of
hyperactivity, or attention deficit
hyperactivity disorder (ADHD), eliminating the following colors from their diet may have some beneficial effects:
- sunset yellow (E110),
- quinoline yellow (E104),
- carmoisine (E122),
- allura red (E129),
- tartrazine (E102), and
- ponceau 4R (E124).
Eating at regular intervals, not skipping breakfast, and getting enough sleep, are good ways to help you maintain your energy levels. Choose foods that are digested slowly. Wholegrain rye bread, porridge, pasta, beans, lentils and noodles are good choices and contain slow-release energy which may help prevent you from feeling lethargic during the day.
As well as eating a healthy balanced diet, it is also important to watch what you drink. Drinking too much caffeine - found in tea, coffee, and cola drinks - can leave you feeling anxious, irritable, and restless.
Try cutting down on the amount of caffeine that you drink. Instead, drink plenty of water. You should be aiming to drink 1.2 liters (6-8 glasses) a day (or more when you are exercising, or when it is hot). If you are not too fond of water, there are plenty of alternatives, such as squash, fruit juice, or caffeine-free fruit tea.
If you exercise regularly, you will benefit from the feel-good factor that you get afterwards. This is due to a release of a chemical called serotonin within your
brain. Serotonin is your body's way of making you feel happier and less stressed.
You should aim to do at least 30 minutes of vigorous exercise every day. When you exercise, it is important that your
heart and breathing rates increase, and you should feel sweaty and slightly out of breath afterwards. Although you should feel tired after exercising, you should not exercise to the point where it is unbearable. Examples of vigorous exercise include:
- going for a brisk walk,
- walking up a hill, or
- carrying heavy bags back from the shops.