A Licensed and Registered Dietitian on what we should know about FAT-
No fat, more fat, low-fat, high fat, don’t eat this type of fat. Confused on what fats you should be eating or not eating? Read on for some back-to-basics information on fats and how to use this information in your diet.
First and foremost, fat is not a “bad” food! In fact, fat is an essential nutrient that helps our bodies in many ways. Here is a quick rundown of all the functions of fat:
- Primary source of energy – Fat provide us with fuel, which we use as an energy source during physical activity, as well as during periods of low energy intake.
- Major fuel source when our bodies are at rest – It is estimated that about 30-70% of the energy used at rest by muscles and organs comes from fat.
- Vitamin and mineral absorption – Dietary fat is essential for the digestion, absorption, and transport of fat soluble vitamins A, D, E, and K.
- Structure/insulation – Structural fat inside the body holds organs and nerves in place and protects them from injury. Fat on the buttocks and palms of the hand protect bones from mechanical pressure. We also have subcutaneous fat which helps preserve body heat and maintain temperature.
- Cell Function – Fats in the form of phospholipids make up the structure of every cell membrane in the body, maintaining the integrity of the membrane. They also help transport substances in and out of cells.
- In addition to the functional purposes of fat, it also provides textural properties and flavor to foods. Fat is responsible for the smooth texture of ice cream and salad dressing, moistness in baked goods, and crisp coating in doughnuts.
However, not all fat is created equal. Most of the fat we eat comes from triglycerides in the form of saturated fat, unsaturated fat, and trans fat. Saturated fats are generally solid at room temperature and are found in foods like butter, cheese, and palm kernel oil. Monounsaturated fats, found in olive oil, peanut oil, and vegetable oil, are liquid at room temperature. Polyunsaturated fats are also liquid at room temperature and include corn, canola, safflower, and cottonseed oils. It is these liquid fats that provide Omega-3 and Omega-6 fatty acids. Animal fats provide energy from saturated fat, whereas plants provide their energy from monounsaturated and polyunsaturated fats.
Trans fats are produced through manipulating the structure of fat in the processing of foods. Hydrogenation of oils is a process in which hydrogen is added to liquid fats, making them solid at room temperature and more saturated. This prevents foods from becoming rancid. Both trans and saturated fats are believed to increase our risk for heart disease. The FDA recently announced in June that trans fats are no longer “generally safe.” Food manufacturers will have to petition to the FDA if they want to use them in their products. To read more about this, visit http://www.washingtonpost.com/national/health-science/what-are-trans-fats-anyway-and-why-are-they-unhealthful/2015/06/22/aa450b3c-15d1-11e5-9ddc-e3353542100c_story.html
How much do we need?
Fat is one of the 3 macronutrients – meaning we need relatively large amounts of these foods in our diet. That is not to say, however, that we can freely eat as many bacon cheeseburgers or as much fried food as we want without any health consequences. Fat is energy dense and a little bit goes a long way. For the average American, 25-30% of our daily intake should come from fat. For a 2000 calorie diet, this would be about 500-600 calories, or 55-60 grams per day. But what exactly does that look like in terms of the actual food? Common sources and the amount of fat provided include: ¼ cup nuts (14 g), 1 tablespoon olive oil (14 g), ¼ cup avocado (6 g), 1 tablespoon butter (4 g). In general, it is important to eat more healthful sources of fat from oils, nuts, and fatty fish (salmon) versus saturated and/or trans fats in margarine and processed baked goods.
The bottom line: Fat is not the enemy! While it is true that food and food products containing fat are higher in calories, these items should not be restricted from your daily food intake. The key is to eat enough fat without going overboard. Dairy products and meats do contain saturated fat, but that does not mean you have to avoid them altogether. Vary your fat sources so that you get mostly monounsaturated and polyunsaturated fats, and limit saturated fats to about 13g per day.