The combination of a healthy diet and regular exercise is the most effective way to maintain a fit body. If you're not consuming a healthy diet, it's challenging to offset poor nutritional choices with exercise. While the calories consumed are difficult to offset with exercise, the impact to your body of eating poorly extends beyond the simple calories you consume.
Weight Loss and an Unhealthy Diet
Weight loss comes down to the number of calories you take in versus the amount you expend each day. To lose one pound of fat, you must expend 3,500 calories more than you consume in a week. Spread out over a week, you need to burn an additional 500 calories per day via exercise to lose a single pound. For the average 140-pound woman, burning 500 calories would equate to a 5-mile run or a one hour spin class. On the intake side, you have the calories you consume through your diet. If you find yourself running through the fast food drive-thru more often than you would like, you'll need to work out even more to offset a fast food meal. The typical fast food meal -- a cheeseburger, fries and a soda -- is about 820 calories. Add in a candy bar for dessert for 300 calories and you've used up two days of your exercise calories - and that's just one meal. If your goal is weight loss, it's hard to be successful if you only exercise but don't also focus on your diet.
Overall Health and an Unhealthy Diet
Poor nutritional choices can lead to high blood pressure, high cholesterol, obesity, greater risk of Type II Diabetes and an increased risk of cancer. In a 2012 study published in "Circulation" by the American Heart Association, researchers found that Chinese adults who ate American fast food twice a week were 56 percent more likely to die of heart disease and 27 percent more likely to develop diabetes compared to those eating none. Increase that to four or more fast food meals each week and the risk of dying from coronary heart disease increased to nearly 80 percent.
Cardiovascular exercise can help to combat these poor effects on the body. As little as 90 minutes of exercise each week lowers your cholesterol and blood pressure. However, no studies indicate that exercise alone can improve your health enough to overcome the damaging effects of four or more fast food meals per week.
Poor Eating Habits and Exercise Motivation
Finish eating a high-fat meal and you probably won't feel like going out for a run. High fat or sugary foods can make you feel lethargic and can even increase your risk of depression. Combine that with weight gain and poor cardiovascular health and you have a recipe for a failing exercise program. It is a challenge for most people to find the motivation to exercise: Not feeling well makes an already daunting task even harder.
Exercise Versus Unhealthy Diet
Participating in regular exercise is always positive, even if it is coupled with an unhealthy diet. Exercise alone, however, cannot prevent the inevitable weight gain and negative effects on overall health that an unhealthy diet creates. If you are struggling to improve your diet, start with baby steps. Drink one less soda per day or cut out one fast food meal per week. It may seem insignificant but these changes add up over time.