Fat is the victim of an unfortunate name. People assume that eating fat makes you fat. But it doesn’t have to. Indeed, fat is a critical component of a healthy diet. It is the most energy-dense macronutrient (at 9 calories per gram) and it provides many of the body’s tissues and organs (including the heart) with most of their energy. All cell membranes are made up of a type of fat known as phospholipids. Fats are also components of some hormones and of chemicals that control blood clotting and muscle contractions, and they provide insulation and protection for nerves. Fat only becomes a problem when you consume too much total fat, or when you don’t eat a good balance of the different types of fat.
Contrary to popular belief, there is no such thing as an optimal level of fat intake that applies to everyone. Research has shown that most people can be healthy on a diet in which fat accounts for as little as 20 percent of total calories or as much as 40 percent. The average American gets 34 percent of total calories from fat. Yes, the average American is also overweight, but people from other parts of the world (for example, France) get even larger percentages of their calories from fat and have much lower rates of obesity. Our problem is not that we get too high a percentage of our calories from fat but rather that we consume too many total calories from all sources. The average French person consumes almost 100 fewer calories per day than the average American.
Reducing fat consumption is an effective weight-loss strategy, because it’s simple to practice. A scientific survey found that a low-fat diet was the most common behavioral habit in a group of more than 4,000 men and women who had successfully maintained large amounts of weight loss for several years.
As important as not eating too little or too much total fat is eating a good balance of different fat types. Most Americans eat too much saturated fat and not enough unsaturated fat. The ratio of unsaturated to saturated fats in the typical American diet is roughly 1:2. The ideal ratio is just the reverse, 2:1 (that is, twice as many unsaturated fats as saturated fats). The largest amounts of saturated fats are found in fatty cuts of meat, whole milk dairy products, fried foods, and baked goods made with certain oils.
Here are some other science-based guidelines for fat consumption:
Limit your consumption of foods with added fat. Some foods contain fat naturally. These include eggs and nuts. Other foods have added fat. These include fried foods and many processed baked goods. If you want to reduce your fat intake, start by strictly limiting your consumption of foods containing added fat.
Limit your saturated fat intake to less than 10 percent of your total calories. If you’re like most Americans, you’re currently getting more than 12 percent of your calories from saturated fat. You can easily make this adjustment by replacing whole milk dairy foods with low-fat dairy foods, choosing leaner cuts of meat, and replacing some whole eggs with eggs whites.
Avoid trans fats at all costs. Trans fats are created when scientists add hydrogen atoms to unsaturated fats to make them more saturated and thereby increase their melting point, make them better for baking and prolong their shelf life. Fortunately, the FDA now requires that trans fat content be listed on food package labels, making it easier to eat around this most unhealthy type of fat. High levels of trans fat consumption have been shown to increase heart disease risk even more than high levels of saturated fat consumption. Meanwhile, both polyunsaturated and monounsaturated fats lower total cholesterol and LDL (the bad cholesterol). If you see trans fat on a product label, simply don’t buy it.
Consume 3,000 mg of omega-3 fats daily. The omega-3 fatty acids DHA and EPA are essential fatty acids (EFA), meaning they cannot be synthesized in the body and must be obtained in adequate amounts in the diet. This is easier said than done, as omega-3 fatty acids are destroyed when the oils that contain them are processed or heated, and most of the omega-3 sources in the modern diet are processed and/or heated. Many experts believe that omega-3 deficiency is one of the most widespread nutrient deficiencies in our society.
Omega-3s create healthier cell membranes. In addition, they are important precursors to anti-inflammatory components of the immune system. Omega-3 supplementation has been shown to improve cardiovascular health, sympathetic nervous system function, immune function, and brain function, and even to promote fat loss. The best sources of omega-3 fatty acids are identical to the best sources of polyunsaturated fats in general: fatty types of fish (salmon, halibut, etc.), flax seeds, and walnuts.
