Take time out to enjoy healthy food, and we don't mean half-eaten burgers. Your body will thank you for it later, says Dr Wynnie Chan

A hectic social life and the pressures of study and then making it up the career ladder mean getting a decent meal, like a night's sleep, can be difficult. Yet it's important to try and eat healthily in your late teens and early twenties because the foundation to a healthy life starts now. This is when the body starts to stockpile precious minerals that could prevent you getting sick in later life.

Any old iron?
The need for iron differs between men and women. We all need iron to make healthy blood and to help develop muscle but in their early twenties women need more amounts of iron to replace menstrual losses. Iron-rich foods are everywhere meat, offal, fortified breakfast cereals, bread, vegetables and even dark chocolate.

It's important to remember that there are two types of iron - haem iron which comes mainly from meats and offals, and non -haem iron which is found in cereals, pulses, eggs, vegetables, fruit and dairy products. Haem iron is absorbed well by the body compared to non-haem iron, although taking extra vitamin C can help. If you need to up your iron intake you should avoid tea after meals, and instead opt for orange juice.

Bone building
Healthy bones and teeth are the result of a calcium-rich diet. From birth to 30, calcium is constantly being deposited in the body. But from then on things go downhill when the calcium starts to be lost faster from the body than it can be replaced. This puts us at risk of osteoporosis in later life - when the bones become brittle and easily broken. It makes sense to insure ourselves against bone loss by eating more calcium in our twenties. Stock up by eating calcium rich foods like milk, cheese, yoghurt, bread, vegetables, and fish with bones. Reduced- fat milk contains the same amount of calcium as whole milk, while for vegetarians, calcium-fortified soya milk and tofu are also great.

Daily dose of D
Vitamin D and calcium are like Posh and Becks, without one you don't get the other. Vitamin D is essential, it's needed to absorb calcium from the gut and to help deposit it in the skeleton. The main source of vitamin D is sunlight but that doesn't mean you have to baste yourself in oil and lie out in it all day - for most people except those who are housebound or among those in communities who have to wear enveloping clothes, a small amount is more than sufficient. Vitamin D is also present in oily fish like herring, salmon and tuna.

The bulk of the matter
Keeping your bowel movements regular is not the preserve of old ladies, fibre is needed by all of us to keep our guts healthy and help reduce our blood cholesterol levels. The average diet contains around 12g fibre, falling short of the recommended amount of 18g. There are two types of fibre, insoluble and soluble. Insoluble fibre helps prevent constipation and is found in wholegrains, potatoes, bran-based cereals, muesli, wholemeal bread, granary bread, wholemeal pasta and brown rice. Soluble fibre reduces cholesterol and can be found in pulses and beans such as lentils, black eye and red kidney beans. If you are getting lazy with your fibre intact increase it by eating wholemeal or wholegrain alternatives e.g. cornflakes with bran flakes, white bread with wholemeal, and adding pulses or beans to meat stews.

Eat more ketchup
Phytochemicals are being hailed as the new wonderfood that will protect us against cancers and heart disease. But if that bit of information fails to light your digestive juices check out where they are found. For example lycopene, a phytochemical thought to reduce the risk of heart disease, is found in high levels in tomato products such as tomato ketchup, canned tomatoes and tomato soup. Another phytochemical compound flavonoids is found in fruits, vegetables, nuts, seeds, tea, onions and apples. Scientific studies have shown that these act as antioxidants, which protect us against free radicals, the nasties that cause cancer and speed up the

How to eat in your late teens and 20s
A healthy diet for young adults need not be boring, you can still eat crisps and chocolate, but keep them for treats. Each day make sure you eat around two to three portions a day of protein. This includes meat, poultry, fish, eggs, pulses such as peas, beans, lentils or nuts. Make sure that you also have three portions of either milk, cheese or yoghurt to bump up your calcium levels. Aim also to eat four portions a day of either bread, breakfast cereals, pasta, rice, potatoes. Try also to fit in five portions a day of fruit and vegetables.

A typical day's eating

Breakfast

• A bowl of muesli or nut-based cereal with chopped papaya and semi- skimmed milk.
• 2 slices of wholemeal toast with reduced-fat spread and marmalade
• Glass of orange juice

Packed lunch

• Pasta salad made with wholemeal pasta, feta cheese, olives and cucumber
• Pot of reduced- fat yogurt
• Banana

Dinner

• Chilli con carne with boiled rice
• Corn on the cob and boiled runner beans
• Baked apple with raisins

Snacks

• Fresh or dried fruit, wholemeal scones, breakfast cereal - choose according to appetite.

The following table should help you work out how best to get your vitamin needs, if you are worried you have a deficiency you should check with your doctor.