Women consider dietary fat to be bad and worry about how much they consume, but in reality, your body needs fat for the absorption of certain vitamins, the production of hormones, to provide structure to cell membranes and to support neurological function and brain cells. Consuming too much fat and too much of the wrong kind of fat contributes to weight gain and health concerns. The American Heart Association and the National Institutes of Medicine provide recommendations on the amount of fat to consume each day based on a percentage of the total calories. Therefore, the number of fat grams depends upon the number of calories consumed.
Total Fat Intake
The National Institutes of Medicine Food and Nutrition Board recommends adults consume no more than 20 to 35 percent of their daily calories in fat each day. A woman who consumes 2,000 calories per day should consume between 40 g to 70 g of fat per day. It is important to not only consume the right amount of fat, but also the right kinds of fat.
Unsaturated Fats
Fat molecules contain carbon, hydrogen and oxygen. The arrangement of the atoms within the molecule determines the type of fat. Unsaturated fats contain double bonds between the carbon atoms and can absorb more hydrogen. Scientists further classify unsaturated fats as either polyunsaturated fats or monounsaturated fats. All unsaturated fats remain liquid at room temperature. Plant-derived foods contain unsaturated fats. Nuts, such as peanuts, hazelnuts and pecans and vegetable oils, such as canola oil and olive oil, contain monounsaturated fats. Fish, including salmon, tuna and sardines, and other oils such as corn oil and soybean oil, contain polyunsaturated fats. These types of fats have proved to help lower blood cholesterol levels, especially when eaten in place of other types of fat. For this reason, the American Heart Association recommends that the majority of the fat grams consumed each day be unsaturated fats.
Saturated Fat
Saturated fats contain a single bond between carbon atoms, and each atom is saturated with hydrogen atoms, meaning the molecule cannot absorb any additional hydrogen. Saturated fats remain solid at room temperature. Animal-derived foods, including meat, poultry, pork, milk, butter and cheese, all contain saturated fat. Saturated fats can cause blood cholesterol levels to increase. For this reason, The American Heart Association recommends adults limit their intake of saturated fats to less than 7 percent of their daily calories. For a typical 2,000 calorie diet, a woman should consume no more than 14 g of saturated fat per day.
Trans Fat
Trans fatty acids, also known as trans fat or hydrogenated fats, are the worst type of fat for your body. Some foods like beef, pork, lamb and butterfat naturally contain some trans fat, which describes the way the hydrogen atoms are positioned within the fat molecule. Synthetic hydrogenated fats have added hydrogen atoms to unsaturated fat to force it to become saturated. These hydrogenated fats, found in foods like margarine, cooking oils and processed foods, have a longer shelf-life but also cause bad cholesterol levels to increase and good cholesterol levels to decrease. Adults should consume no more than 2 percent of their daily calories in trans fats. This means a woman on a 2,000 calorie diet should intake no more than 2 g of trans fat per day.
References
- American Heart Association: Know Your Fats; January 2011
- U.S Department of Agriculture: Dietary Guidelines for Americans 2010 -- Chapter 3; February 2011
- National Institute of Medicine Food and Nutrition Board: Dietary Reference Intakes; 2004
- Centers for Disease Control and Nutrition: Dietary Fat; February 2011
Member Comments