Why do I have to limit the amount of fat in my diet?

Although fat is an essential nutrient and a carrier for other essential fat soluble vitamins, it is a dense source of calories and should be limited. The American Heart Association recommends that fat be limited to 25%-35% of your total daily calories (approximately 55-75 grams per day for a moderately active person). Limiting your total fat intake also allows you to consume a more balanced diet with calories from a variety of sources and thus a variety of nutrients. 
Kelly Traver
Internal Medicine
Fat is the most misunderstood macronutrient of all. People never seem to know whether fat is universally evil or a good thing to have in their diet. The answer is that all fats are not created equal. There are good fats, and there are bad fats. Proteins and carbohydrates deliver 4 calories per gram, while fats deliver 9 calories per gram. This is true whether the fat is good or bad. So, since fats deliver more calories than proteins or carbohydrates, you need to watch your fat intake because either one can quickly bring you to your desired calorie limit.

Fat matters in other ways besides calories, though. Different kinds of fat often promote entirely opposite physiologic consequences in your body. In short, there are two kinds of good fat and two kinds of bad fat. The good fats are unsaturated-either polyunsaturated or monounsaturated. The bad fats are saturated- either naturally or through a chemical alteration that creates trans fats. Recent research suggests that saturated fats may not be quite as bad as we had previously thought (although trans fats are harmful); however, a healthy diet is still considered one that minimizes both saturated and trans fats.
Weight Watchers®
Heart disease is the nation's number one killer, and too much fat in your diet -- especially saturated fat and trans fat -- raises your risk for cardiovascular disease. Keep total fat intake between 20% to 35% of calories, with most fats coming from sources of polyunsaturated and monounsaturated fatty acids, such as fish, nuts, and certain vegetable oils. These types of fats have been shown to provide health benefits. Less than 10% of your daily calories should come from saturated fat, and keep trans fat consumption as low as possible.

With Weight Watchers you could already be on your way to having a healthier heart. Keeping your weight in check will help lower your risk of many chronic illnesses.

Weight Watchers offers a comprehensive approach to weight loss that can help you reach your goals.
Doreen Rodo
Nutrition & Dietetics
One reason to limit fat is because it contains more than twice the calories per gram as compared to protein and carbohydrate. It has 9 calories/gram whereas carbohydrates and protein both have 4 calories per gram. Saturated fats come from meats, dairy and eggs and high amounts can increase cholesterol and cause heart disease. There are also fats called "trans fats" which can raise your "bad cholesterol" and lower your "good cholesterol". Trans fats are found in commercial baked goods, shortening and some margarines as well as boxed crackers and snacks. The best fats are the monounsaturated fatty acids that are found in olive oil and canola oil. They help to lower "bad cholesterol" and increase "good cholesterol". Polyunsaturated fats are found in oils, fish, nuts and seeds. One of their roles is to help to lower your total cholesterol.

It is important to know the different kinds of fat and to limit your total intake of them due to the calories. Choosing the right fats can be an important part to your daily diet, but eat them in moderation.
Laura Motosko, MSEd, RD
Nutrition & Dietetics

The Academy of Nutrition and Dietetics recommends limiting fat to 20 to 30 percent of calories in your diet. Excess fat intake leads to elevated low density lipoprotein cholesterol levels which is a risk factor for development of plaque in your arteries, heart attacks and stroke. Per gram fat is higher in calories than protein and carbohydrate which may lead to excess calorie intake and obesity, increasing your risk of cancer, and other chronic diseases.

Lona Sandon
Nutrition & Dietetics
Certain types of fat can increase your levels of LDL cholesterol and therefore increase your risk of heart disease. Too much fat can also pack on the calories leading to excess body weight. You should limit the amount of saturated and Trans fat you eat according to the American Heart Association guidelines and the 2010 Dietary Guidelines for Americans. Foods high in saturated fat include full-fat milk, yogurt, and cheese, fatty meats, butter, and cream based foods. Trans fats are typically found in snack foods such as crackers, chips, snack cakes, and bakery goodies.

You should try to get most of your fat from plant based sources. These include vegetable oils, soft-tub margarines made with vegetables oils, avocados, nuts, natural nut butters, and seeds. Look for low-fat or skim versions of milk, yogurt and cheese and buy only lean meats to help keep fat in check.

Continue Learning about Healthy Eating Guidelines

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.