This is not to promote this sect of Christian. Featured in National Geographic, Seventh-day Adventist christians are among the top listed groups who lives a longer life along with the Japanese people and other group from Italy. Part of this groups secret is non-smoking, regular exercise and non-alcoholism. As most other Christians believe that our body is a temple of God, these group observes healthy living.
Also, a large percent of Adventists are vegetarians which i think is a big factor in for this group. Do you still need to be among this group to observe a healthy living? Or simply obeying God the creator will do.
To begin with, let's have a look at that article if you can provide us with a link to it.
Secondly, not smoking is definitely good for health. So is non-alcoholism (generally, but not always). So my opinion is that neither do you have to believe in God to have good health, nor do you have to be an adventist. Just don't smoke or drink and exercise regularly, take good care of your body. Religious beliefs don't have much to do with your health, unless you're actively physically doing something to improve your health.
Also, the National Geographic should have checked out the Yogis of North India, and maybe you should read "Autobiography of a yogi" by Swami Paramahansa. These Yogis are extremely agile and fit even at very old ages, and their "secrets" are a combination of extremely healthy eating (generally vegetarian), and regular yoga.
The only reason religious beliefs tend to have anything to do with health is that many religions forbid any form of self harm, including self harm that is associated with habits that have a cumulative effect such as smoking, drinking, or eating unhealthy foods.
The way I see it, people should just let loose once in a while. I mean, if you genuinely enjoy the life of never smoking, never drinking, never eating junk food, never eating red meats, then go for it. But most people crave at least one of those things once in a while and my question to them is, what's the point of living another five or ten or maybe 20 years if you aren't enjoying it a little?