Protein and fats have specific jobs in your body that no other nutrient can do. From your brain all the way down to your toenails, cells require these crucial nutrients. Fats even help proteins do their job by acting as messengers. Your body can’t make all the protein and fat it needs so you have to get some of it from foods.
Essential Amino Acids
Amino acids are the building blocks of protein. Your body can make 10 of the 20 amino acids that exist, but the other 10 must come from food. Proteins are necessary for growth, your immune system, making hormones and enzymes, repairing tissues and preserving lean body mass. Amino acids also make the neurotransmitters in your brain which allow your brain cells to communicate. Neurotransmitters control your mood and alertness, and even your behavior.
Protein Requirements and Sources
The 2010 Dietary Guidelines for Americans recommend that 10 to 30 percent of your calories come from protein, or approximately 46 grams for women and 52 grams for men daily. Healthy sources of protein include lean meats, poultry, seafood, beans, nuts and seeds. Dairy products also provide protein. Choose lower fat versions to avoid eating too many calories and fat.
Essential Fatty Acids
Fats protect your organs, are needed for growth and development, absorb certain vitamins and provide energy. About two-thirds of your brain is made of fat. Fats protect your brain cells and are found in the membranes that control what goes in and out of each cell. Your body can’t make all the fats it needs and you must get some from food, including omega-3 and omega-6 fatty acids.
Fat Requirements and Sources
The 2010 Dietary Guidelines for Americans recommend that 25 to 35 percent of your calories come from total fats. Healthy fats include vegetable oils such as canola and olive oils, avocados and the fats found in nuts and seeds. Avoid foods that contain trans-fats or high amounts of saturated fats. Keep your saturated fat intake to less than 10 percent of your calories. As part of your fat intake, your body needs omega-3 and omega-6 fatty acids. Women need about 12 grams and men need about 17 grams of linoleic acid, an essential omega-6 fatty acid. The recommended dietary allowance for alpha-linolenic acid, an essential omega-3 fatty acid, is 1.1 grams for women and 1.6 grams for men. Omega-6 fatty acids are found in vegetable oils and omega-3 fatty acids are found in fatty fish.
- National Institute of General Medical Sciences: What Do Fats Do in the Body?
- The Biology Project: The Chemistry of Amino Acids
- McKinley Health Center: Macronutrients: The Importance of Carbohydrate, Protein, and Fat
- The Franklin Institute: The Human Brain: Nourish-Proteins
- U.S. Department of Agriculture: Dietary Guidelines for Americans
- The Franklin Institute: The Human Brain: Nourish-Fats
- Linus Pauling Institute: Essential Fatty Acids
- Comstock/Comstock/Getty Images