I want my friends and family to live a long time, so that’s why I’m writing this. (Everything I write in this post is my opinion and isn’t meant to be taken as medical advice.)
According to physicians I’ve come to trust, there are five main things that one needs to prioritize when it comes to longevity. They are: nutrition, exercise, sleep, emotional health, and exogenous molecules and supplements (i.e., vitamins, minerals, medications).
All of those things are important; here is my estimation of their priority.
Emotional Health: I would say that the most important is emotional health. One has to want to live long and well. So many people give up when they get to an advanced age—they let their fire go out. And when the fire goes out, they fade away and die. We keep the fire going by regularly adding emotional fuel, by identifying and pursuing a purpose, by identifying and pursuing values, and also by setting goals for longevity. Do we want to live to 90, or 100, or, in my case, 120? Perhaps even longer? (The new record is 124!)
Exercise: I would rank exercise second. If exercise were a drug, it would be the most effective drug against many of the main causes of death: cardiovascular disease, stroke, cancer, diabetes, and Alzheimer’s. The studies and literature I’ve seen are emphatic that exercise is effective. It’s got to be the right “dose” of exercise—the right mixture of strength training, cardiovascular training, and stretching. Of course, these ratios will vary from one person to the next.
Sleep: I think sleep is the third most important. (If one exercises well, it enables one to sleep better.) Insufficient sleep can shorten your life. Sleep longer, live longer. The studies done by Michael Walker, Ph.D are compelling; he says that at least seven hours of good-quality sleep will enhance health, well-being, and longevity.
Meds and Supplements: Next, exogenous molecules and supplements—drugs to manage our blood pressure or cholesterol as needed, and to ensure that we have all of the right biochemicals floating around in our bloodstream. I think regular blood tests are important.
Nutrition: Nutrition frequently leads this list, but, provided one is not eating a completely horrendous diet (such as the Standard American or “SAD” Diet, or any other version of loading junk into their body), I think this is less important than the other four. The doctors I trust recommend eating lots of protein and fat, (yes, fat!), and avoiding sugar like the plague. They also recommend minimizing carbohydrates that convert rapidly to sugar, and instead focusing on complex carbohydrates.
Lest you think I’m an ultracrepidarian (somebody who gives guidance and advice without expertise), all of the above comes from reading studies and being advised by competent physicians, such as Doctors Peter Attia and Param Dedhia.
I hope you find this information helpful.