How to stay young? Become a dancing, dog-loving vegan

Seriously. You can find out your fate right now. Just stand up, take off your shoes, cross your legs and lower yourself down to the ground, without using your hands, your knees or any other part of your body. Then try and stand back up the same way. It's harder than this chap is making it look - and it reveals a lot about muscle strength and balance.

You start with a score of 10 and lose one point for every other body part you use and half a point if you wobble. These scores are a powerful indicator of how long you're going to live. If you score 8 - 10, a long, healthy life is on the cards. A score of 6 - 7.5 means you're almost twice as likely to have a shorter life. 3.5 - 5.5 and you're at risk of not having a particularly long life at all... Find out more about how the test was devised here.

You can improve your score! It's about physical strength so any kind of exercise will likely have a positive impact. In fact, just practising the test itself will increase your score.

That's right, it's almost all up for grabs. Only 25% of our health is predetermined by our genes.

RELAAAAAAX. 30 per cent of us complain of being overly stressed, and that stress has the potential to be really damaging. Stress creates the chemical cortisol, and excess cortisol weakens muscles, degrades bones and can shorten life by up to five years.

Two identical twins, Patty and Terry, were tested to see how well they'd aged (how their biological age compared to their chronological one) and the results revealed the sister with the least stressful existence was "youngest." While presenter Chris van Tulleken discovered that his body is five years older than it should be. Stress is literally shortening his life, and increasing the chances of him getting age-related diseases like cancer and diabetes earlier. Scary, right?

Being overweight is bad - no surprises there - but so is the kind of fat you can't see.

When you age, your body stores fat around your organs and that can be a major problem. Women are more vulnerable to it than men, and lack of exercise and a poor, high fat and sugar diet, can contribute to it.

But, as presenter Angela Rippon found, sometimes it's a problem in spite of a healthy lifestyle. And that's where lentils come in. Eating high resistance starch, found in lentils and chickpeas, helps. As does inulin food supplements, which breaks down internal fat stores.

Research has found that the vegan diet is the healthiest diet of all, reducing the risk of cancer, stroke and heart attack. You see, the animal protein we eat promotes growth but as you get older the exact same thing speeds up ageing. The more you replace meat with veg protein, the slower you age.

If you can't face giving up steaks and bacon entirely, a reduction in meat-eating still has positive effects. Van Tulleken is now taking up meat-free Mondays, for example...

Muscle shrinkage and weakening is almost inevitable as we age (from our 30s onwards is speeds up "rapidly"), but dancing is one of the best exercises to help us stay young.

An experiment in Germany saw 20 elderly men and women dance for three hours a week, while another 20 trained in a gym. After six months the dancers saw a 15 per cent improvement in muscle strength, while the gym group had little difference. Dancing stimulates more muscles, tests your flexibility and uses your brain and your balance. It's more "comprehensive and holistic."???

Nuts actually protect against heart attack. A study revealed that people who ate one handful of nuts five times a week had half the risk of heart attack compared to those who didn’t. And walnuts are best. “Nuts are an easy fix to live longer," says van Tulleken.

Studies have found that animals have a significant impact on our stress levels (and too much stress makes us age earlier, remember?). Van Tulleken carried out a small test on employees who are allowed to bring their dogs to work and found the presence of a pooch lowered the participant's blood pressure and even made them better at the task at hand.

However you find your chill, keeping your stress levels in check is vital to staying young. If dogs aren't your thing, Van Tulleken recommends "exercise, meditation and 'me time'" as good alternatives.

Is that cup half full or half empty? If it's half full, chances are you'll live longer. Optimism can actually add years on to your life. If you’re an older person with a positive attitude about your age it can help you live up to 7 years longer. And if you’re a young person with a positive attitude about growing older that can halve your risk of a heart attack.

Let's all look on the bright side, eh?

How to Stay Young continues on Thursday at 9pm on BBC1