You just need to follow these six simple steps

Take your pick of the many books promising to show you the quickest route to weight loss and you’ll get an earful of different advice: go low-carb; cut sugar and alcohol; try gluten-free; detox; follow the latest diet advocated by a super-slim Hollywood star.

There’s never any shortage of suggestions, — but what none of these guides to becoming ‘a new you’ ever seems to question is whether you should be trying to lose weight in the first place.

You might think this goes without saying if you are classified as ‘overweight’ or ‘obese’, according to the most commonly used standard today, the Body Mass Index (BMI). Yet, as I explained in Saturday’s Mail, carrying extra weight can actually be beneficial to your health.

Size is no bar to exercise: Dancing for fitness in the Channel 4 series Big Ballet

The science now shows that people in the BMI range 25-34 (and particularly those in the ‘overweight’ range, 25 to 30) may enjoy significantly lower mortality rates than do their ‘normal weight’ counterparts.

Over the past decade this ‘obesity paradox’, as it has become known, has been endlessly discussed in the most prestigious medical literature. But what does it mean for people like you who want to know the ‘secrets’ of living a long and healthy life?

Should you be trying to gain weight and get into the ‘overweight’ club if you have a BMI of 24? And if you already have an obesity-related condition, but are not in the severely overweight category, should you try to gain yet more body fat?

The answer to both of those questions is a definite ‘No’. As a cardiologist who has been in practice for 30 years, and written more than 800 scientific papers on the heart and its diseases, I believe that preventing weight gain in the first place should always be the primary goal (unless, of course, you are underweight, with a BMI below 18.5).

However, the reality is that many people are already overweight/obese — and my message is for them.

As many can attest, losing those extra pounds or stones is challenging. But the good news is this: even without losing weight you can be as healthy as, or even healthier than, your thinner friends.

The secret lies in making sure that you are physically fit. Studies suggest that if you maintain or improve your cardio fitness and muscle strength, changes in weight are unimportant.

Keep active: As many can attest, losing those extra pounds or stones is challenging. But the good news is this: even without losing weight you can be as healthy as, or even healthier than, your thinner friends

I realise this is hard to sell. Many people don’t enjoy working out and would prefer to control their weight just by dieting. It takes about 35 miles of walking to burn off 1lb of fat, whereas a diet can have a much faster impact over the course of days or weeks. But, in the long run, who can stick with a 1,000-calorie-a-day diet? Who wants to starve themselves?

And if you’re doing this by following a low-carb protocol that makes you feel deprived, you’re less likely to have enough energy to exercise. So your weight ends up fluctuating dramatically, and all the while you lose out on the benefits of exercise. You probably don’t feel great either. No wonder most diets fail.

You can start with something simple, like getting off your backside

Staying physically fit, on the other hand, not only boosts your health but improves your mood, too. I’m not suggesting you should run a marathon or take up body building. You can start with something simple, like getting off your backside. And I’m not being flip in suggesting that.

Sitting was described in one recent study as being as ‘insidious’ as lighting up cigarettes or over-exposing oneself to the sun, because it negatively influences things like high-density lipoprotein (the good cholesterol), blood sugar, resting blood pressure and the appetite hormone leptin (which tells you when to stop eating).

I hope the following guidelines will help you do a little less sitting and a little more of the activities beneficial to your health.

As you will see, they are far from exacting. I cannot tell you precisely what you should be eating for dinner, how many pounds is too many, or when to lose an inch off your waist.

Instead, I want to empower you to take control of your body and your health, thinking through your myriad lifestyle choices until you find your own way of being fat but fit.

PRINCIPLE 1: THE NUMBERS GAME

For years we thought that the optimal BMI was around 23 (right in the middle of the ‘normal’ range). Now I am comfortable saying that a BMI of 27 is the new 23.

But the only really important thing in terms of numbers is that you should avoid being at either end of the BMI spectrum; so neither morbidly obese (BMI 40 and above) or painfully thin (BMI less than 18.5).

The benefits of fitness cannot completely outweigh the cons associated with either of those two severe body types, and the benefits are best felt in the spectrum between 18.5 and 35.

Find your own place within that range and — even if the charts say you are overweight or even mildly obese — you don’t need to focus on losing weight, providing that you are physically fit (for an indication of how fit you are, see Principle 6).

Remember, fitness trumps weight loss — and no matter what images of willowy/skeletal models on magazine covers might suggest, thin and out of shape is worse than being overweight and fit, or even obese and fit.

PRINCIPLE 2: CHANGING THE CONVERSATION

If you had to give a number between one and ten as to how much your weight factored into your happiness (one being not at all, ten being a lot), what would you say?

My guess is that your answer will be above five, and that this will have as much to do with society’s obsession with thinness, and your worry about how you will be perceived by others, as it is to do with fears about your health.

The anti-obesity movement focuses too much on thin versus fat, instead of healthy versus unhealthy, and all of us need to change the conversation to one that concentrates on fitness instead.

What we eat is obviously important. But I’d much rather tell an overweight or obese patient to work on improving his or her fitness level than severely cutting back calories.

Not only does this approach have a more positive spin, but it tends to promote weight loss without all the stressful thoughts of ‘going on a diet’ for the sole purpose of shifting surplus pounds.

To me, what matters is how strong someone’s cardio-respiratory system is — not what size dress or trousers they wear. And since the science has shown that you can be remarkably healthy at many different BMI values, let’s change our vocabulary so that we no longer talk about losing fat but think instead about gaining health.

PRINCIPLE 3: KEEP TRACK

Although I don’t want anyone to become addicted to checking his or her weight, numerous studies suggest that tracking your weight on a regular basis can help us to maintain it. How frequently is up to you, but aim to check at least once or twice a month.

Keep track: Numerous studies suggest that tracking your weight on a regular basis can help us to maintain it

PRINCIPLE 4: IMPROVE YOUR METABOLIC HEALTH

When patients ask me how they can enhance their health without going on a traditional diet, or even thinking about weight loss, my advice is simple:

Maintain regular sleeping patterns. Laboratory studies have shown that virtually every system in the body is affected by the quality and amount of our sleep, including our appetites and how fat we get.
People who keep a regular sleep schedule are typically healthier by every measure and have an easier time maintaining health and fitness, so aim to go to bed at the same time, weekend and holidays included, and make sure you’re getting the seven to nine hours a night sleep which most of us need.
Keep moving. Be aware that you can increase your fitness all day long just by moving as much as possible. If you have a desk job, make an effort to get up and move for a few minutes at least once an hour. Take and make calls on a hands-free phone, so that you can walk around as you talk. Park at the far end of your office car park. Generally, be creative in seeking ways to move your body despite obligations that would have you remain sedentary.

PRINCIPLE 5: DON’T BUY INTO DIETING MYTHS

I realise that some of you will be unable to resist trying to drop a few pounds, no matter what.

If so, bear in mind some of the most widespread myths about dieting. This will help you reframe the word ‘diet’ in your head and hopefully approach your efforts with patience and realistic conviction, rather than frustration and anxiety.

Common misconceptions include the idea that ‘slow and steady works best’.

Don't buy into myths: There's more than one way to lose weight. Find what's best for you

In truth, many trials suggest that this simply isn’t the case. Whether you lose weight slowly on a semi-ambitious diet, or go on a more restrictive diet that has you losing weight quickly, both types of diet can work in the long run.

You just need to do what works for you — and that includes skipping breakfast if you feel like it.

Every diet book I’ve read seems to preach the importance of that first meal of the day, but two recent studies that looked at the difference between eating breakfast and skipping it showed that it made no difference when it came to losing weight.

Also, note that a diet doesn’t have be focused on weight loss. In 2013, researchers at one American university found that by concentrating on not gaining weight, rather than being obsessed with losing it, people are more likely to stay committed to a long-term plan and avoid that dreaded weight creep over the years.

PRINCIPLE 6: PRIORITISE FITNESS, REGARDLESS OF WEIGHT

In my studies, I’ve seen over and over again how critical it is to avoid low levels of fitness for your age and sex — and what matters is just getting started.

Indeed, the biggest increase in health benefits is seen in those moving up from the bottom 20 per cent of fitness levels within a particular age group to the next stage up, 20-40 per cent.

That’s still below average, but, even if you don’t ever make it to the top 20 per cent, you will still have reaped tremendous rewards in those first stages.

As for how fit you are now, this is my advice. In general, if you can climb several flights of stairs without difficulty and can walk a mile or two at a decent pace (e.g., a mile within 15 minutes), then you are in good shape at any age, whether you’re a man or woman.

EXERCISE CAN BOOST YOUR GENES

Fitness doesn’t just make us feel better. There is mounting evidence that it can alter the way our bodies operate genetically.

Leading neurologists have recorded stunning changes when it comes to the impact of exercise on the brain. Some experts in this field would go as far as to say that physical exercise is one of the most powerful ways to trigger beneficial changes at a genetic level.

While we clearly cannot alter the genes we are born with, we can change the way that some of them express themselves.

Research has shown aerobic exercise (or ‘cardio’ exercise) — which increases your body’s need for oxygen and includes activities such as running, walking, swimming and biking — not only encourages the expression of genes linked to longevity, but also targets an important gene that encodes the brain’s ‘growth hormone’.

This hormone is called Brain-Derived Neurotrophic Factor (BDNF). More specifically, aerobic exercise boosts production of BDNF and has been shown to reverse memory decline in elderly people, actually triggering the birth of new cells in the brain’s memory centre.

The positive effects of exercise on our genes are not confined to cardio work, however.

In 2008, a team of Canadian and American researchers demonstrated the power of strength training (muscle-building exercises) when they evaluated the effects of a six-month programme in volunteers aged 65 and older. The scientists found that this type of exercise can help reverse the ageing process at a cellular level.

By the end of the trial, the expression of about 200 genes, known to become more or less active with age, had changed. And the genetic profiles of the elderly volunteers who’d gone through the strength-training exercises resembled those of a far younger group.

In terms of muscle mass, you can probably just take a good look at yourself in the mirror to see if you’ve got better-than-average muscle tone.

And you’ve probably got some decent muscle strength if you can complete your normal daily activities, including lifting heavy objects like children or grocery bags, without much strain.

There’s usually room for improvement, but this doesn’t have to involve formal workout sessions lasting hours at a time.

I recommend that you aim for 30 to 40 minutes of aerobic exercise on most days of the week.

It doesn’t matter whether it’s walking, jogging, biking, climbing stairs or swimming.

You can do whatever exercise you like as long as it gets your heart rate up at least 50 per cent from its resting state. (Seek medical help to make sure you are healthy enough for physical activity before beginning any new exercise routine — especially if you are usually sedentary and have cardiovascular risk factors.)

In addition, try to work your big muscle groups twice weekly by using light weights or gym equipment, or via classes geared towards this goal, such as Pilates or yoga.

And if you’re using classic barbells, here’s a simple rule to follow: lift enough weight to complete 12 to 15 repetitions without considerably straining yourself. If you can do endless repetitions, you need to increase the weight to gain the health benefits.

Finally, bear in mind that the benefits of exercise are, for the most part, cumulative. If you dedicate a single period of time to your exercise regimen, don’t allow yourself to be sedentary for the rest of the day.

Even just breaking up your sitting time by walking around with a pair of free weights and doing a few bicep curls can lower your risk of disease and premature death.

But health isn’t only about your physical shape. It’s also about your mind and psyche, which are also remarkably improved by physical activity and exercise.

For decades, we’ve pushed diets rather than exercise — and yet the number of chronic health challenges continues to climb.

It’s time the scientific community re-examined its definition of fat and how it can actually be a good thing, as long as you are fit. Once we embrace that idea, we can all move a little more, rest a little easier and live longer and healthier lives.