Do you look your age?

Some people are expert at guessing the age of others at first sight because their brain, consciously or otherwise, processes certain variables which help them to evaluate how old the other person is. And some are the opposite: they are the ones who should keep their mouths shut when it comes to guessing someone's age in order to avoid offence, because when they open their mouth they seriously put their foot in it. Because few things upset us as much (let's be honest) as when people think we are older than we are.

Even if we can count ourselves among the first group, the ones who calculate age well, with some individuals it is very difficult because they look much younger than they really are. What features do they share, to give that impression? Three experts - a plastic surgeon, a dermatologist and one of Spain's most renowned anti-ageing experts - give us an idea.

As we age, our back tends to curve because of changes to the discs between the vertebrae. This means that as we get older we are less erect when we walk and we can even become shorter. This phenomenon starts around the age of 30 and although it takes time to be noticeable, it is there. It is a sign of our age. So, if someone does not have that curvature of the spine, they immediately appear to be younger. "Young people stand straighter and that influences the appearance of the abdomen and their way of walking, which is lighter," explains José Serres, president of the Spanish Society of Anti-Ageing Medicine and Longevity (SEMAL) and one of the best-known experts in anti-ageing medicine in Spain.

"Moving awkwardly makes you look older," agrees plastic surgeon José Manuel Béjar, of the San Juan de Dios hospital in Vizcaya. So if we want to look young, we have to avoid stiffness and a swaying walk as well as certain gestures that send a message to the brain of anyone watching us that 'there goes an elderly person'. Rubbing our eyes, putting our hands on our kidneys and arching our backs, leaning forward as we walk or walking very slowly...anything that makes us look tired also makes us look old.

Wrinkles, blemishes, sagging jaw, bags and dark circles under the eyes - if any of these are obvious then we are going to look older than we are. A good skin is not a matter of luck: genes are important, yes, but it is also a matter of the care (or martyrdom) to which we have subjected ourselves. Also, skin is very quick to show age and wear and tear.

"People who have spent too much time in the sun or in tanning cabins will already look older than they are by the time they are 30 or 35," says Natalia Jiménez, a dermatologist at the Ramón y Cajal hospital in Madrid and specialist in the look of skin. A dry skin needs more work in order to look good, she says, otherwise, it adds years to us. "If we look at celebrities who look good for their age, none of them look tanned and there's a reason for that. Johnny Depp, Tom Cruise and Penelope Cruz are just some of the famous people who are ageing well," Jiménez says.

"Some anatomical features are associated with young people. One is very important: people with a rounded face and barely noticeable cheekbones look younger, more childlike," says Natalia Jiménez. Asians are a clear example: their faces have few sharp features and that is why they appear to withstand the passing of the years better. Their childlike appearance (round face and soft contours) lasts longer than in western people. Their pale skin and the fact that they avoid exposure to the sun also helps.

Then there are the everlasting teenagers, like Leonardo DiCaprio. "People with the face of a child always appear younger than they are, but that is totally genetic," says José Manuel Béjar, who explains that age causes the face to look more skeletal. "The subcutaneous cellular tissue, the 'fat' that we have below the skin, is gradually lost and the bones of the face become more noticeable. That makes us look older," he says. So in other words, the sharper the features the more aged or even ill we look. "It seems that as we get older our nose grows, but that isn't the case. What happens is that it becomes more noticeable," says Dr Béjar. So soft, barely defined contours help our faces to look young for longer.

As we age we lose muscle and gain fat. And, as muscle means strength and firmness (it supports the skin so it doesn't sag), our appearance reflects the loss of these qualities which are linked with youth. This is why a person who, through exercise and good lifestyle habits, manages to maintain a suitable proportion of fat and muscle will always appear younger and avoid the bulging stomach and cellulitis (especially in women) which adds years. Look at actor Russell Crowe, for example, who now has a prominent belly and flabby arms. "He has aged a lot," says José Serres. "George Clooney and Tom Cruise, on the other hand, look very good for their age".

Someone who transmits vitality and cheerfulness tends to seem younger than a person who looks fatigued and sad. Think of the before-and-after photos used in advertisements for cosmetics or therapies. Sometimes there is not much difference between the images, but in the one showing the 'good results' the person usually appears happy and energetic, instead of looking worried or weighed down by life. Maybe this is Spanish presenter Jordi Hurtado's 'secret of eternal youth': he is always smiling, dynamic, tireless. "And then genetics, self-care and maybe a bit of sprucing up helps," says Serres.

There is a saying that after a certain age we have to choose between our faces and our buttocks because we can't have both. There is no scientific basis to this, but it is more or less correct. "Obesity makes us overestimate someone's age, but if a person loses a lot of weight at certain ages it makes their face look tired and that is ageing as well," says Natalia. José Serres, meanwhile, adds that extra weight improves some wrinkles and flabby skin, but the downsides are poorer health, more clumsiness and a worse shape. The ideal is to find a balance and not follow 'yoyo diets'. People who always maintain the correct weight will help their body to seem younger.