The American Cancer Society recently released its guidelines for diet and physical activity. As is typical for these sorts of dicta, there are multiple authors (more than 20) not one of whom is a physician. The guidelines can be shortened to if it tastes good, don’t eat it. If it has any amount of alcohol in it, don’t drink it. Exercise more than you might feel necessary. It’s the same sort of opinion heavy, data light “health” recommendations that have been force fed to the public for generations. It’s likely to have the same effect on behavior that its predecessors had, which is to say not much. These edicts may make school lunches even less palatable than usual, but otherwise will likely be ignored.

Why the constant need to scare the public into behavior patterns that they find unpleasant? A large part of this desire to get us to eat a “healthy” diet and to exercise more comes from an inner need of people who claim they have our best interests at heart, but who secretly wish to make us conform. Eat that extra hot dog and you’ll get cancer. That’s if the organization issuing the guidelines is in the cancer business. If they work for a heart group, the hot dog will give you a heart attack.

Guidelines such as those from the ACS are based on weak observational studies which show effects that are so blurred that they are impossible to apply to an individual subject. Just below, I’ve listed the 10 leading causes of death in the US. Two of them really don’t belong on the list because they lead to death from something else. Diabetes predisposes to cardiovascular disease, while Alzheimer’s Disease (often a general lumping together of all forms of dementia) makes its victim at risk for infections and accidents.

  1. Heart disease
  2. Cancer
  3. Accidents
  4. Chronic lower respiratory diseases
  5. Stroke
  6. Alzheimer’s disease
  7. Diabetes
  8. Influenza and pneumonia
  9. Kidney disease
  10. Suicide

Let’s start with general rules for a healthy long life. Foremost is luck. Choose the right parents. Doing so will provide you with a good set of genes and a good upbringing. Good luck will reduce the risk of an accidental death. There’s also a role for luck in the generation of cancer. This controversial idea is that a bad cell division – ie, an unlucky one – can cause a cancer. Bad luck doesn’t exclude other preventable causes of cancer, it just means that you’re better off being lucky.

OK, luck is beyond control. What can one do do preserve health without making life unbearable? Remember the character in Catch-22 who because he was in a war and might die prematurely, only engaged in very boring activities so as to make what time he had left seem to pass more slowly. That’s out too.

First, keep your weight at a reasonable level. Unless you’re crazy, any diet that keeps your poundage at a reasonable level should be alright. What’s a reasonable weight? A body mass index (BMI) of 18-25 is said to be optimal. A large study published in JAMA indicated that 25-30 might be better; 30-35 was no different from 18-25 with respect to longevity. Thus, there’s likely a fairly large range of weight that is optimal for people who are generally in good health.

Looking at the above list shows that heart disease is the leading cause of death in the US. The leading causes of heart disease are high blood pressure and diabetes. If you have neither, are not sedentary, and keep your weight at a reasonable level, as defined above, you’ve likely done as much as possible to prevent it. A Mediterranean diet in such an individual probably will have no discernible effect on the subsequent development of heart disease. Of course, if you like such a diet, go for it. If you have hypertension or diabetes then you should be on a diet appropriate for these disorders.

The data that cancer can be prevented by dietary modification is flimsy at best. What is unequivocally beneficial is to avoid prolonged exposure to sunlight, don’t smoke, and avoid exposure to known carcinogens. And again, be lucky.

Number three on the list is accidents. diet won’t help here and exercise increases the risk of an accident. Wear your seatbelt (almost impossible not to these days) and don’t drive like an lunatic. Don’t combine travel and alcohol. Otherwise, a modest intake of alcohol will likely not do any harm.

Suicide is on the list. Enough said. In general, use your head and exercise good judgement. If you’re healthy and want to stay that way, common sense will take you as far as you can go. Major dietary manipulation and an programmed exercise regimen may be necessary, on doctor’s advice, if you already have a medical problem. Otherwise, enjoy life. Even the longest of them is quite short.