It may seem as obvious as Posh's boob job, but you ARE what you eat. With this in mind, we reveal the most nutritious food types for a more youthful appearance

Fabulous fruit and vegetables

Your five-a-day is vital when it comes to achieving a healthy, glowing complexion, supplying it with a fabulous source of vitamins, minerals, fibre and water. Along with nourishing and cleansing, Vitamin C strengthens capillaries and collagen, while Vitamin C, beta-carotene (the pigment found in carrots, apricots and mangoes) and Vitamin E (in avocados and kiwi fruit) all neutralise the effects of free-radicals which can contribute to premature ageing.

Best sources of Vitamin C are citrus fruits and juices, slow cantaloupe, strawberries, tomatoes, sweet peppers and green peas. Potassium, which is found in all fruits and vegetables, helps regulate fluid balance in the cells and so combats puffiness and fluid retention.

Rich in Vitamin C and beta-carotene and good at zapping free radicals, blueberries are one of the best anti-ageing foods. Best eaten raw when their Vitamin C content is at its highest, sprinkle them on your cereal and do your skin a favour!

Great whole grains

Whole grain foods are rich in fibre, which benefits the skin in a number of ways. They are also good for the digestive system, helping you stay fuller for longer and reducing constipation. And when your digestive system is working well, your skin will radiate health and vitality.

Whole grains are also rich in B Vitamins such as B2 and B3, which can help maintain normal skin function. Step up intake of whole wheat, oatmeal and brown rice, and avoid refined cereals such as white bread, white flour and white rice.

Whole grains, along with wheat germ, also contain selenium, a mineral antioxidant that can help minimise the damage of ultraviolet light, while research has shown that it might even aid in skin cancer prevention. Zinc can also be found in whole grains, which assists in maintaining elastin fibres and collagen to promote firmer skin, while helping to reduce and prevent wrinkles.

Perfect protein

Skin is predominantly protein, however protein molecules are not absorbed through the epidermis into underlying tissues, so you need to supply proteins through the foods you eat. If you are deficient in protein, your hair, skin, teeth and nails will all suffer.

This key building block for the body is found in poultry, fish, eggs, meat, cheese, dried peas, beans, chickpeas, cereals and soy. Fish is a great and healthy source of protein; eat at least two portions a week.

If you love red meat, eat it sparingly and opt for lean cuts. Vegetarians can get their protein from soy products such as tofu and soya milk. Pumpkin, sesame and sunflower seeds are also packed with protein, fibre and many beautifying nutrients.

Wonderful water

Nearly two thirds of our body weight is made up of water. This is stored in the cells, outside the cells and in our body fluids. We need water to aid digestion and elimination, and when we don't get enough, toxins get trapped in our tissues, causing the complexion to deteriorate while prompting the start of the ageing process. There's no doubt about it, well-hydrated skin looks years younger.

Fabulous fats and oils

Excluding fats and oils, particularly the beneficial unsaturated variety, can be bad news for your looks. Fats are a must for getting moisture into the skin. Look out for HL cholesterol, the 'good' cholesterol, which has been shown in high levels to protect against heart disease.

Step up intake of safflower, corn, olive, peanut and canola oils, nuts, seeds and fish like salmon and mackerel. Use butter in moderation and choose unhydrogenated margarines, which have not been subjected to the solidifying process that causes them to behave like saturated fats.

Avocados contain the most potent anti-ageing combination - Vitamins E and C - which mop up ageing free radicals. If you don't like or eat fish, hemp oil is a good vegetarian source of omega-3 fatty acids. It's also rich in Vitamin E, a great antioxidant, and useful in preserving youthful skin.

Fantastic fish

Oily fish such as salmon, herring, mackerel and sardines are the main source of the important fats called omega-3 fatty acids.

These have a number of hugely beneficial anti-ageing properties. According to dermatologist Nicholas Perricone, author of The Perricone Prescription, a salmon-packed diet can help smooth out lines and wrinkles while lifting and firming skin.

Fish oil containing the omega-3 essential fatty acid EPA helps to prevent wrinkles and can delay the ageing process of the skin, according to research (published in the Journal of Lipid Research in 2005). EPA has also been reported to help reduce the negative effect of UV rays caused by over exposure to the sun. Aim to eat two portions a week.