After 30, diets don't work anymore, the metabolism slows down, and it’s all downhill from there.

But is that really right? Does the metabolism come to a grinding halt after age 30? After all, if middle age spread was an inevitable consequence of aging, why bother dieting or exercising?

If you look around at the physiques of people out and about, whether it be in the gym, supermarket, local pub or elsewhere. The evidence is there. Younger people tend to be leaner and seemingly in possession of faster metabolic rates than older individuals.

It’s true that when you’re young, your body finds a way to balance energy expenditure and energy intake, remember eating chips and chocolate everyday and not gaining a pound. It’s true that, as we age, we have a much more difficult time maintaining what we’ve got. These truths, however, don’t seal our fates. Just because some people spend their lives in a frustrating battle of eating less only to gain more, that doesn’t mean you have to.

Scientists have spent quite a bit of time sorting out what happens to the metabolism with age. And what they’ve noticed is that while the metabolism does seem to slow with age, it only slows if you do nothing about it. If you eat properly and exercise the right way, you can maintain your metabolic rate over your entire life span! Even if you’re age 40 or older and things have already slowed down, you can reverse the trend and regain the metabolism of your youth. In fact, you can create a metabolism that’s even faster than the one of your 20s! So why does maintaining a healthy weight get tougher as we age? Well, although most people eat less as they age to compensate for moving less at their desk jobs, their activity levels generally decrease more than their energy intakes. And with less activity than food, fat gain is inevitable.These decreasing activity levels result in yet another problem: muscle loss. Researchers have determined that, starting between the ages of 25 and 30, most people lose roughly five to 10 pounds of lean body mass during each decade of life. As muscle is a metabolically active tissue, that means that in addition to burning calories to move your skeleton through space, it also burns calories to maintain itself. So age-related muscle loss can cripple your metabolism. The average person who becomes less active and consequently loses muscle experiences a 20 to 25 percent reduction in 24 hour metabolism (measured as the amount of energy your body burns in 24 hours) by age 65. This adds up to a daily metabolic drop of more than 500 calories from age 25 to 65.

So it’s no wonder we're gaining weight! It’s tough to cut 500 calories off your daily menu to compensate for that metabolic drop, so most people end up packing on the fat. Of course, again, this scenario holds true only if you do nothing to prevent it. Why do most people lose muscle as they age? Because they don’t use it. When it comes to the human body, what you don’t use, you lose, and muscle is no exception.

Studies of people older than age 60 show that you can, at any age, reverse muscle loss and regain the metabolism of your youth. In fact, according to research, individuals who maintain their lean mass (muscle, bone and other non fat tissue) through exercise and smart eating as they age experience only a 0.36 percent drop in metabolism per decade compared to the five to seven percent per decade drop that most adults experience. This is a huge difference! Add a few key supplements to the mix, and you can even prevent that 0.36 percent drop and possibly even rev your metabolism higher than it was during your youth! So metabolic slowdown is not inevitable. You can prevent it. And you can reverse it using a three-pronged approach including eating, exercising and supplementing the right way.

The following tips are essential to maintaining a fast, youthful metabolism:Build the muscle needed to speed up your resting metabolism (the number of calories your body burns to maintain life) all day and all night long. A gain of five to 10 pounds of lean mass muscle will rev up your resting metabolism by roughly 100 calories - each and every day.

Increase the number of calories your body burns as it digests foods. Eating more metabolically costly proteins, metabolism boosting healthy fats, antioxidant rich fruits and veggies and the right carbs at the right times can boost your metabolic rate by another 100 to 200 calories per day. That’s right. The very food you eat can increase fat oxidation and metabolic burn. You just have to know which foods are right for the task at hand.

Boost the number of calories your body burns through movement. Thanks to that desk job, family commitments and a great line up of must-see TV, most of us move less at ages 30, 40 and beyond than we did during our teens and 20s. By training at least three hours each week, you can increase your calorie burning. But don’t just limit your thinking to planned “gym time” physical activity. By including more physical activity of all types, you can maximize the metabolism.

All told, with the right combination of training, nutrition and supplementation, you can expect to increase your daily calorie burn by between 40 and 60 percent within just eight weeks. In other words, a guy who currently burns 2,500 calories a day would rev up his metabolism to a 3,400 to 4,000 daily calorie burn! That’s enough of a boost for you to see a 10 to 15 pound drop in body fat during those eight weeks above.

And for those at a beginner/intermediate level of training, you can expect muscle gain as well. Muscle gain and fat loss simultaneously.

Even more important, when you get these things right, you will simultaneously improve your health. In addition to speeding your metabolism, building muscle and shedding fat, you can also expect to lower your blood cholesterol, blood pressure and blood sugar. So not only can you look better, you can live longer. So, in the end, I’m here to tell you that a large scale metabolic decline isn’t inevitable as we age. If you’re young and haven’t seen the affects of father time, that’s excellent. But that doesn’t mean you wont! Make sure you use a combination of smart eating, training and supplementation to keep that metabolism reving for life.

And if you’re older and your current lifestyle has negatively impacted your body, it’s not too late. Turn things around now, and you can reverse the damage that’s been done. I’ve seen it happen time and time again.