On New Year's Day more than a few of us annually resolve to change our lives--or at least our more self-indulgent habits. On the hunch that all good things flow from physical and mental well-being, Scientific American Body offers this list of recommended resolutions based on the advice of health professionals and the scientific literature. Whatever your goals, it will help you understand why hardly anything you could choose to do would have a bigger impact on your quality of life.

Perhaps the best New Year's resolution is coming up with a strategy to sensibly tackle each of the five listed below. New Year's resolutions are notoriously unsuccessful because people have a superficial commitment to them, notes health psychologist Frederick Gibbons of Iowa State University. Whatever behavior you want to change requires a specific plan for going about it.

For instance, to quit smoking or to moderate drinking, people might want to plan ahead for situations or cues they need to avoid, since they may face social pressure, even if it's unintentional pressure. That might also include tempting foods, Gibbons says. Social support is also critical. Warren Franke, director of Iowa State's Exercise Clinic, believes that success toward an exercise or weight-loss goal could mean enlisting a significant other or a buddy to work out or diet with you or joining a formal program.

Controlling drinking may even require taking part in a behavior-modification treatment, Gibbons adds.

In pursuing these resolutions, set short-term goals, such as losing just one pound a week, Franke says. If you sometimes find yourself sliding, such as trying that killer cheesecake, don't feel bad about yourself and give up. Accept that was a bad day and that [the] next day will be a good day. And reward yourself. Life's too short not to enjoy it. Don't buy yourself six scoops of Ben & Jerry's, mind you. I have a friend who, if she's lost weight, buys herself People magazine. It's a simple pleasure she enjoys, and it works.

1 Stay Active

Exercising three times a week for about 30 minutes each session has been shown to cut cardiac morbidity and mortality by more than 10 percent, explains Seth Feltheimer, a general internist at New YorkPresbyterian Hospital/Columbia University Medical Center.

To reap the maximum benefit from exercise, your pulse has to stay above 100 beats per minute. This requires more than an average walk, where you might often stop and start at each corner and can't really get a chance to get the pulse up, Feltheimer adds. Franke agrees and recommends that you do whatever exercise you enjoy enough to do regularly and that is vigorous enough to increase your heart rate, be it walking with a neighbor or a high-intensity aerobics class at an exclusive fitness club.

If you compare a person who is 30 pounds overweight but physically active with someone who is thin but a coach potato, you'll find the thin couch potato has a higher risk of premature death and of some chronic diseases, such as diabetes, heart disease and hypertension, Franke says. Of course, the best combination is to be physically active and relatively close to normal weight, but if there was a choice, without hesitation I'd choose a little bit overweight but fit.

2 Eat Healthy

Reducing cholesterol intake by 20 percent and getting total cholesterol levels below 180 will improve a person's risk of heart disease by 20 to 30 percent, Feltheimer notes. Healthy diets should include at least five servings of fruits and vegetables a day, Franke declares. This ensures that you get more vitamins and minerals, which most people don't do, and will likely increase fiber intake as well, he explains. It will also be more filling, making you less likely to cheat and ingest more calories by nibbling on snacks.

It's somewhat of a clich, but the most important thing to do is to eat healthy and moderate your food intake, Franke notes. Feltheimer concurs and offers a strategy to help with moderation: Don't eat until you can't eat anything else. You should always leave the table feeling you can eat a little more.

Moreover, as the experts note, many people's downfall is that they think of diets as temporary impositions that they can drop once they have reached a goal weight. Rather a truly healthy approach to eating means making lifestyle and behavioral changes that last. So find a diet you can truly live with for the long haul.

3 Quit Smoking

It's the advice you have probably been hearing for most, if not all, of your life. Yet despite the ubiquitous warnings, smoking is still the leading cause of preventable death in the U.S. The World Health Organization estimates that by 2015 tobacco will be responsible for 10 percent of all deaths--killing 50 percent more people than HIV will. Quitting smoking may be one of the most common New Year's resolutions, but it is also easily one of the most valuable to keep.

Cigarette smoke contains 69 known carcinogens and increases risks for most forms of cancer, particularly of the lung, kidney, larynx, head, neck, bladder, esophagus, pancreas and stomach. Smoking also increases blood pressure and the risk of heart disease while decreasing the good, or HDL, cholesterol that lowers the risk of heart failure. The result is that every year, nearly 140,000 men and women in the U.S. die from cardiovascular disease attributed to smoking, according to the Centers for Disease Control and Prevention.

The financial costs are also considerable. At 7 a pack, a pack-a-day smoker is spending almost 50 a week and 2,600 a year--and that does not include any of the financial costs associated with the medical problems of smoking.

4 Drink Appropriately

Because of excessive drinking, which is defined as anything more than two drinks a day for men and one a day for women, over two million people in the U.S. have liver disease. Excessive drinking also increases the risk for heart disease, high blood pressure, stroke, inflammation of the pancreas and certain forms of cancer, especially cancers of the esophagus, mouth, throat, larynx and possibly the breast, colon and rectum.

Roughly 10 to 20 percent of heavy drinkers also develop alcoholic cirrhosis, or scarring of the liver; those with life-threatening cirrhosis may need liver transplants. In addition, Gibbons notes that statistics indicate the more heavily you drink, the greater your risk for interpersonal problems.

Yet studies suggest that moderate drinking-- for men, two or fewer drinks a day, and for women, no more than one--lowers the risk for cardiac disease and death by heart attack or stroke.

By these measures, moderate drinkers fare better than both heavy drinkers and abstainers. Researchers believe moderate drinking helps to ward off cardiovascular disease by thinning the blood and thus suppressing the formation of blood clots that can cause heart attacks and strokes. Alcohol also seems to enhance the body's ability to break down small clots.

5 Relieve Stress

We've known for years that chronic stress leads to increased risk of premature death, even in the absence of other things it's connected with, such as not taking care of yourself or high blood pressure, Franke explains. Some of the physiological mechanisms are clear. Stress leads to your body producing cytokines or other inflammatory agents. In chronic stress, you carry on such responses to an abnormal extent, past what the fight-or-flight response was perhaps meant to handle, wearing down the body.

Furthermore, various studies have established that chronic stress can cause excessive blood clotting, leading to blockages and strokes, Feltheimer says. It also decreases the responsiveness of the immune system. And with chronic stress, some cytokines can in essence degrade the structural stability of plaques lining blood vessels, which is analogous to making a blister more prone to popping. So that can contribute to a heart attack if it does pop.

People need to focus on things that are within their control. It's wasted energy to stress about what's outside your control, Franke says. Try to downshift and go with the flow, and if there are situations you can't downshift with, then avoid them if possible.