Fitness and Low Fat Diets

Your diet affects your ability to perform physical activities by providing an adequate energy supply and supporting a healthy cardiovascular system. Taking in too many calories, regardless of the source, leads to an unhealthy level of body fat. However, a diet that provides a healthy amount of fat and the right number of calories supports an active lifestyle, as well as a healthy heart and weight.

Low-Fat Diet

A high-fat diet is one that gets 40 percent or more of its calories from fat; an eating plan that limits calories from fat to 20 percent of overall calories qualifies as a low-fat diet. The Dietary Guidelines for Americans 2010 recommends the adults get 20 to 35 percent of calories from fat, indicating that a low-fat diet meets basic nutrient needs. If you have specific medical concerns, consult with your doctor to design a diet and workout plan that meets your health and fitness needs.

Types of Fat

The connection between fitness and diet isn't limited to the amount of fat you take in, but is more affected by the types of fat you consume. Saturated and trans fats raise cholesterol levels, which can put your heart health at risk. The American Heart Association recommends that you limit saturated fat to no more than 7 percent of total calories. That translates to 126 calories, or 14 g, in an 1,800-calorie diet. Trans fat should be eliminated from your diet or should provide less than 1 percent of total calories, at the most. That means no more than 2 g of trans fat in an 1,800-calorie diet. No trans fat is better.

Fitness

Exercise and diet go hand in hand when it comes to building a healthy cardiovascular system. Your heart is central to your health and fitness. Your heart is healthier when you control your blood pressure, cholesterol and weight through your eating habits, including eating a healthy amount of the right kinds of fats. Exercise helps manage these factors while improving your cardiovascular fitness. When you exercise aerobically, you train your heart and muscles to work more efficiently. Progress in your cardiovascular fitness is evident after three to four weeks of regular physical activity; if you had trouble walking two miles the first week, for example, you'll notice that the same workout gets easier with practice. When a workout becomes less challenging, add time or intensity to continue seeing improvements to your cardiovascular endurance.

Considerations

Limiting fat in your diet to 20 percent of calories is one way to lower your overall calorie intake, manage your cholesterol and improve your heart health. However, if you make up for calories cut from fat by eating too many protein and carbohydrate-rich foods, this can lead to an unhealthy body weight and too much body fat. Your body stores extra calories as fat in the form of triglycerides, regardless of the source of those calories. Consult the Dietary Guidelines for Americans to identify a healthy calorie target for your age and activity level. Staying active supports a healthy weight and complements a balanced diet.