Despite widespread attention to diet, calorie intake may not be a major factor in causing death by heart disease, according to a 17-year study of almost 9,800 Americans. Instead, losing excess weight--or not becoming overweight to begin with--and exercising may do more to ward off death from heart disease.
Interestingly, when I entered medical school I was focused far more on exercise than diet as a solution to health. Exercise is far less controversial and complex to recommend than diet though. Unfortunately, the vast majority of diet experts still have yet to adopt the nutritional typing or limited-grain principles of nutrition into their recommendations.
Exercise really needs to be viewed as a drug and very few clinicians or patients understand this. I believe it is one of the most powerful "drugs" that we have in the treatment of type 2 diabetes. Unlike typical commercial drugs, exercise can actually cause one to go into permanent remission for diabetes. While I am a major fan of exercise and encourage all my patients to exercise as well, it is very unwise to exclude optimal nutrition from the program as many exercise fanatics do. Although they won't die from heart disease as this study suggests, cancer is far more likely if one ignores optimal nutrition. Since cancer is the number two cause of death it would certainly seem more than prudent to combine exercise and diet together in one's health program.
It is the rare person who can stay healthy on fewer than three exercise workouts per week. You would have to be very healthy already and just be in maintenance mode. If you are overweight, have high blood pressure, high cholesterol or diabetes, then you will want to consider a daily exercise program, working up to one hour per day until you normalize the problem. It is essential to understand that if you are unfit you will need to progressively increase the intensity of the exercise to achieve the same metabolic benefits. While walking will work beautifully for many initially, eventually most people will need to progress to some form of running/walking or walking uphill to maintain the same benefits. Fortunately, a treadmill will allow you to walk up-hill continuously without having to run and suffer the ravages of increased forces on your knees. I am also a major fan of the elliptical trainers if you have access to them.
Science Blog November 5, 2003