Could you be starving your skeleton? Adequate amounts of protein, calcium and the sunshine vitamin - vitamin D - are essential to build and maintain healthy bones. Read on for the best ways to safeguard them at the key stages in life.
Lots of people worry about their appearance and weight, but few bother to stress about the state of their skeleton - even though ignoring our bones may have devastating implications in later life.
Osteoporosis, a disease that affects one in three women and one in five men, occurs when bones lose density. It results in large holes in the delicate honeycomb structure of the skeleton, which then leaves bones very prone to fracture.
Building healthy bones during the teens through the 20s is key, but lifestyle changes at every age may also reduce the risk of suffering from a condition that admits one person to hospital every 6 minutes in Australia.
"Many people disregard osteoporosis as just a condition affecting the elderly, and don't realise that there are many steps they can take at different ages to improve their bones," explains Sarah Leyland, helpline manager at the UK's National Osteoporosis Society.
"While bone loss occurs naturally in everyone as they get older, broken bones because of osteoporosis are not an inevitable part of ageing."
The condition is associated with post-menopausal women because the protective effect of oestrogen is lost after this time. The lifetime risk of a fracture in women at age 50 is greater than the risk of breast cancer or cardiovascular disease.
"Osteoporosis is often referred to as the 'silent disease' as it may remain undetected until the time of the first broken bone, which commonly occurs in the wrist, hip or spine," Leyland says.
Check out our guide to maintaining bone health throughout the key stages in life.
:: Birth to 10
Research shows that bone quality in old age depends largely on diet and lifestyle as babies, children, and young adults.
Bone-building cells (osteoblasts) work much harder in young children than bone-eating cells (osteoclasts) in order to help the skeleton grow - so they need ever increasing amounts of calcium.
What bones need: Up to 550mg of calcium a day. Calcium-rich foods include dairy products such as yoghurt, calcium-fortified soy milk, orange juice, and green leafy vegetables.
Custard, rice pudding or soy-based drinks are other good sources of calcium. Foods with slightly less calcium include baked beans, cereals, bread, cheese spread and dried fruits.
:: Age 10 to 18
Bones stop growing in length at around age 18 but continue to strengthen until the mid 20s.
Girls and boys need around 1000mg of calcium a day. Eating disorders can also affect future bone density.
What bones need: As well as a healthy diet containing calcium-rich foods, exercise is key as it makes our skeleton stronger. Muscles pull on the bone when we move, encouraging new growth.
A Sheffield University study found that it was possible to increase the bone density of teenage girls by giving them extra milk over just 18 months.
Children may find it difficult to absorb enough Vitamin D from food sources such as egg yolks and milk, but exposure to the sun's UVB rays for just six to eight minutes, four to six times per week should provide enough Vitamin D. During daylight savings months it is advisable to get your sunlight before 11am and after 3pm as the cancerous risks to the skin during the middle hours of the day outweighs the Vitamin D benefits.
:: The 20s
Bone mass development reaches its peak in the early 20s, so this is the time to 'bank' bone for later in life.
There are concerns that people aged 18 to 24 are unaware of how important it is to stock up on calcium at this time. Instead of building bone health during the vital teens and 20s, they are endangering it by indulging in junk food, smoking, alcohol, and taking little exercise.
What bones need: Young adults need around 700mg of calcium a day, contained in milk and dairy products, including low fat varieties.
Other foods containing calcium include almonds, sesame and sunflower seeds, broccoli, tinned salmon, sardines or pilchards - but make sure you eat the bones as well. Leafy green vegetables such as kale are also good sources of calcium.
Breast feeding mothers may need to boost calcium intake further, by around an extra 550mg (around two glasses of milk a day). Pregnant women should not take Vitamin D supplements without seeking a doctor's advice.
Resistance training and weight-bearing exercise like jogging, dancing, tennis - even running up and down stairs - help build bone and can reduce stress levels.
This is important as cortisol - the hormone released when we are stressed - suppresses bone formation and may lead to a decrease in calcium absorption.
:: 30s to 50s
Bone loss starts around now - in the 30s the rate at which bone is broken down starts to exceed the rate at which new bone is formed.
Women lose around 10% of their bone mass in their 40s and 50s as they go through menopause, due to the drop in oestrogen levels.
Men's bones are more protected because they continue to produce sex hormones all their life.
Taking certain drugs, such as oral steroids, over a long period (for conditions such as asthma), may affect bone density. Illnesses such as Crohn's or coeliac disease can also interfere with the body's capacity to absorb nutrients.
What bones need: A good diet and regular exercise - at least three times a week for a minimum 20 minutes - will help prolong the life of your bones.
:: Check out bone health
Those concerned about bone health, maybe because of a history of osteoporosis in the family, or have already suffered broken bones or lost height, should consult a GP.
They may be referred for a bone density test (the Dual-energy X-ray Absorptiometry; DXA) offered by specialist clinics and available on medicare for some people.
For more information call Osteoperosis Australia: (02) 9518 8140 or their website: www.osteoporosis.org.au