But no matter how many creams and potions you try, unless you eat well and provide your body with the nutrients it needs, your skin will remain dry, your nails brittle and your hair will lack shampoo-commercial shine.

Beauty therapist Katie Hooker from The Beauty Lounge in West Wollongong says diet has a big impact on the health of your skin. Conditions such as dehydration, dryness and eczema are directly related to what you put inside your body. Others, such as acne, can be worsened but are not caused by diet alone.

"Your skin is an organ, so every single thing you put into your body can affect your skin," she says.

"Like the rest of your organs, if you're feeding them properly, they're going to be working more efficiently than they otherwise would."

Hooker gives all her clients a skin consultation before they start any beauty treatment to see whether changes in their eating habits will improve their skin problems.

A memorable case of dietary habits affecting skin health was a client whose skin was extremely dehydrated from drinking several litres of Coca Cola a day. She cut back her consumption and it helped fix the issue.

But it's not just a matter of cutting out sugary processed foods. Eating foods that promote healthy skin, hair and nails is also important.

Hooker encourages her clients to drink lots of water to hydrate the skin, eat several serves of fruit and vegetables a day for a boost in antioxidants, which protect the skin and slow the ageing process, and to snack on almonds and Brazil nuts for protein to help keep the skin lubricated and plump.

Eating protein also helps repair damaged cells thus improving the health of hair and nails, which themselves are made up of a protein called keratin. Oily fish, eggs, red meat and sea vegetables are high-protein foods and can help return your dull locks to their former glory.

Naturopath and author Janella Purcell says "it's definitely you are what you eat" with vitamin B12 (seafood and eggs), vitamin C (oranges), and vitamin E (sunflower seeds and spinach) helping improve hair through scalp circulation, stimulating growth.

According to Purcell if the hair, skin and nails are all looking in need of some TLC, it's possible you are deficient in zinc, one of the minerals responsible for growth and cell regeneration.