In today's society, people are increasingly concerned about the amount of fat and cholesterol found in the foods that they eat. This concern is usually related to an effort to achieve and maintain a healthy body weight, since fats and oils are a concentrated source of energy (calories) compared to carbohydrates or protein. In addition, research has shown that certain fats (e.g., saturated fat and trans fat) and dietary cholesterol raise low-density lipoprotein (LDL) or “bad” cholesterol levels, a major risk factor for heart disease.
But that is only half the story. First, reducing fat alone may not lead to weight loss. To successfully lose weight, you must decrease overall calorie intake - whether from fat, carbohydrate or protein - or increase calories used (physical activity).
Second, not all fats are bad. Fat is needed in the diet to supply essential fatty acids (nutrients that are essential for growth and not produced by the body) and help the body to absorb fat-soluble vitamins. When consumed in moderation, some fats belong in a heart-healthy diet. For example, unsaturated fats may help lower LDL (“bad”) cholesterol levels when used in place of saturated fats, as part of a heart-healthy diet. Therefore, the types of fat consumed may be more important to overall health and wellness than how much fat you consume in a day.
In general, the best strategy for reducing saturated fat and trans fat intake is to read food labels and eat a balanced, heart-healthy diet. Tips on reducing total fat intake, saturated fat and trans fat intake, as well as strategies for including heart-healthy fats and following a heart-healthy diet are discussed in this article. The Dietary Guidelines for Americans, Food Guide Pyramid and nutrition labels are also useful tools in determining daily food intake.
Effects of fats on heart health
Food provides the building blocks (nutrients) and fuel (energy) that our bodies need to function properly. The foods we eat and our dietary patterns play an important role in the prevention and treatment of chronic diseases such as heart disease, high blood pressure (hypertension), obesity and diabetes. According to the American Heart Association (AHA) a heart healthy diet and lifestyle changes are essential strategies for reducing the risk of heart disease.
Based on the latest scientific research, the National Cholesterol Education Program (NCEP) recommends targeting our low-density lipoprotein (LDL) or “bad” cholesterol levels by lowering our intake of saturated fats, trans fats and dietary cholesterol, participating in regular physical activity and achieving or maintaining a healthy body weight.
Fats come in several chemical forms, some healthier than others. They are divided into two broad categories: saturated and unsaturated. Saturated fats and trans fats – fats that have been altered chemically to behave like saturated fats – have been shown to promote the formation of hardened arteries (atherosclerosis) and coronary artery disease. In contrast, mono and polyunsaturated fats, including omega-3 fatty acids can have cardioprotective effects as part of a heart-healthy diet.
Saturated fats cause the liver to produce more cholesterol, increasing our total blood cholesterol levels and particularly the harmful low-density lipoproteins (LDL) or “bad” cholesterol levels, which have been linked to an increased risk of heart disease. In fact, blood cholesterol levels are more strongly linked to our saturated fat intake than any other type of fat in our diet, including our dietary cholesterol intake – the cholesterol found in foods. Therefore, it is important to watch out for products labeled “low cholesterol” or “no cholesterol” that are still high in saturated fat content. These products can raise blood cholesterol levels due to their saturated fat content and are dangerous to heart health, even though they may not contain any cholesterol.
Although unsaturated, trans fats or “partially hydrogenated” oils (those oils that have gone through the hydrogenation process) acquire many of the properties of saturated fats. In the body, trans fat has been shown to be a more hazardous risk factor for heart disease than saturated fat. Studies have shown that dietary trans fats can increase levels of LDL or “bad” cholesterol just like saturated fats. They have also been shown to decrease levels of HDL or “good” cholesterol and may increase triglyceride levels and lipoprotein levels, increasing our risk factors for cardiovascular disease.
Cholesterol is a waxy fat that is present in all human beings. There are two sources of cholesterol that can contribute to your blood cholesterol levels or lipid profile. The first source is the liver, which manufactures about 80 percent of the cholesterol. In fact, people do not need to consume any cholesterol from diet, as the liver can make all the cholesterol the body needs. Therefore, cholesterol is not an essential nutrient. The second source of cholesterol is our diet. Dietary cholesterol is found naturally in animal products such as meat, eggs and dairy products. Only foods of animal origin contain cholesterol. If you have high total cholesterol or LDL cholesterol levels, limiting dietary cholesterol intake to 200 milligrams per day is recommended.
It is important to remember that not all fats are unhealthy. For example, omega-3 fatty acids – found in high amounts in oily fish such as salmon, mackerel, or albacore tuna – may help reduce cardiovascular risk. Polyunsaturated and monounsaturated fats found in vegetable oils such as canola, olive or peanut oil, can lower blood LDL cholesterol levels when substituted for saturated fats in our diet. So, when it comes to fat, the advice is simple: eat less red meat, whole-fat dairy products and processed foods that may contain hydrogenated fats, and substitute heart-healthy unsaturated fats from plant sources, fatty fish, nuts and seeds.
Fat intake recommendations
Eating too much of certain fats may increase our risk of developing chronic diseases such as heart disease and high blood pressure(hypertension). One strategy for lowering cardiovascular risk is to eat a well-balanced heart healthy diet low in total fat, saturated fat, trans fats and dietary cholesterol. This does not mean cutting fat completely from our diets. In fact, heart-healthy fats are necessary for good health. The National Cholesterol Education Program (NCEP) recommends:
Twenty-five to 35 percent of one’s daily calorie intake should come from fat. Since most foods high in fat are also high in saturated fat and calories, limiting total fat intake may help to maintain healthy weight and blood cholesterol levels.
Saturated fats: Less than 10 percent of total daily calorie intake. If you have heart disease or are at high risk for developing it, then saturated fat should be limited to less than 7 percent of total daily calories. Studies have shown that diets high in saturated fat increase LDL cholesterol and total cholesterol levels. The good news is that the opposite is also true and reducing the amount of saturated fat you eat can help lower your blood levels of LDL cholesterol and total cholesterol.
Polyunsaturated fats: Up to 10 percent of total calorie intake. These fats lower LDL or “bad” cholesterol, but can cause small reductions in HDL or “good” cholesterol when substituted for the saturated fats in the diet. It is important that the dietary sources of polyunsaturated fats come from liquid vegetable oils and semi-liquid margarines that are low in trans fats.
Monounsaturated fats: Up to 20 percent of total calories. Monounsaturated fats reduce LDL or “bad” cholesterol without lowering high-density lipoprotein (HDL, "good" cholesterol) levels when substituted for saturated fats in the diet. People consuming a traditional Mediterranean diet high in fruits, vegetables, whole grains, fish and unsaturated fats (especially monounsaturated fat from olive oil) generally have lower rates of cardiovascular disease.
Trans fat: Should be limited as much as possible by avoiding foods prepared with partially hydrogenated vegetable oils. Trans fats raise LDL cholesterol, increasing the risk of heart disease. Avoid hydrogenated or partially hydrogenated fats (listed under the ingredients list on food labels), hard margarines or packaged foods prepared with these ingredients.
In addition, the American Heart Association (AHA), along with the National Academy of Sciences (NAS), recommends eating more heart-healthy omega-3 fats from plants and fish – particularly fatty fish such as mackerel, lake trout, herring, sardines, albacore tuna and salmon. The AHA recommends eating at least two servings of fish per week.
Choosing heart-healthy fats
Although fats are necessary for good health, some fats are healthier than others. Saturated fats and trans fats – fats that have been altered chemically to behave like saturated fats – have been shown to promote the formation of hardened arteries (atherosclerosis) and coronary artery disease. In contrast, mono and polyunsaturated fats, including omega-3 fatty acids can have cardioprotective effects as part of a heart-healthy diet. To promote cardiovascular wellness and reduce heart disease risk, the following are some heart-healthy tips to help you balance and manage the fat in your diet:
Choose to bake, broil, grill or roast dishes instead of frying. Prepare foods with salt-free herbs and seasonings, low-fat or fat-free broth, lemon juice or cooking wine to keep them moist.
Stir-fry or sauté foods using only small amounts of vegetable oil, such as canola oil, extra-virgin olive oil or safflower oil. Avoid cooking with or adding butter, lard or shortening, which are high in saturated fat and cholesterol. Also, read the ingredients lists on food labels to avoid foods prepared with “tropical oils” (i.e., coconut oil, palm kernel oil, cocoa butter and palm oil), which are very high in saturated fats.
Choose sauces and gravies that are prepared without high-fat ingredients, such as heavy cream, butter, margarine, mayonnaise or animal fats or “drippings.”
Choose lean meats. Remove the skin from poultry products and cut away any excess fat from meats before cooking and eating. Both traditional (e.g., chicken and turkey) and non-traditional (e.g., emu or ostrich) poultry are lower-fat, cholesterol alternatives to beef. Seafood is also a healthy substitute for red meat, but make sure not to fry it or drown it in cocktail sauce or butter.
Choose low-fat or fat-free milk and dairy products. Gradually switch from whole-fat dairy products to 2 percent, 1 percent, to skim or fat-free milk. There are low fat versions of most cheeses available on the market. Also, non-dairy creamers contain saturated fats and could be gradually replaced with fat-free milk.
Read food labels. Information about the total fat, saturated fat and cholesterol content of foods can be found on the Nutrition Facts label. Use the information provided on food labels to compare similar products.
Read the ingredients list on food labels. Processed foods made with partially hydrogenated vegetable oils such as cookies, crackers, or baked goods, may be high in trans fats. Also avoid commercial fried foods such as French fries, onion rings or donuts, which are other major sources of trans fats.
Choose fats and oils with 2 grams or less of saturated fat per tablespoon. Avoid hard margarines, particularly those that contain partially hydrogenated or trans fats. Because softer typically means less saturated, the softest margarines are the most desirable. Choose liquid or tub margarines, canola, olive, safflower, corn or soybean oils.
Cooking with heart-healthy fats
One of the best ways to monitor your intake is by cooking fresh foods rather than eating out or purchasing prepared foods. In this way, any added ingredients, such as fats, oils or salt, can be controlled during preparation. Because some oils are more heart healthy than others, the type of oils used in food preparation will have an impact on the type and amount of fatty acids obtained through your diet. For example, although they both contain the same amount of fat per one tablespoon, coconut oil has almost 12 grams of saturated fat, while safflower oil has less than 1 gram. More over, safflower oil is a good source of heart-healthy monounsaturated fats. The following are some suggestions for replacing ingredients in your favorite recipes to lower their total fat, saturated fat and cholesterol content:
When baking, 2/3 cup of vegetable oil may be substituted for one cup of butter or margarine.
When cooking or baking, one cup of evaporated skim milk may be substituted for one cup of heavy cream.
When baking, three tablespoons of cocoa powder dissolved in one tablespoon of vegetable oil may be substituted for one ounce of unsweetened chocolate.
Part-skim ricotta cheese may be substituted in recipes that call for cream cheese (e.g., cheesecake).
Use plain or Dijon mustard instead of mayonnaise or other fatty sandwich spreads.
Non-fat frozen yogurt may be substituted for ice cream, and is also available without sugar. Furthermore, yogurt can be substituted for high-fat sour cream when making dips, dressings and toppings.
Adding fat is not necessary for flavor. No-salt seasonings, herbs, or garlic can add flavor without adding fat.
Either 2 egg whites or 1/4 cup of cholesterol-free egg substitute can be used instead of a whole egg.
Generally, it is difficult to recommend just one particular “general purpose” oil, as some oils may not suit certain purposes due to their particular taste or due to their “flash” point – the temperature at which they smoke. For instance, olive oil is generally not suitable for baking, but serves quite well as a marinade, or as a dressing for salads, bread or pasta. The overall goal should be to reduce saturated and trans fats in favor of unsaturated fats, using the healthiest oil suitable for a particular use and to consume fats or oils in moderation. Please see the table below as a general reference.
Food values: Selected Fats and Oils
Oil per serving
Calories (kcal)
Total Fat (g)
Sat. Fat (g)
Mono- unsat. Fat (g)
Poly- unsat. Fat (g)
Chol. (g)
Canola 1 tbsp (14g)
123.76
14
0.99
8.25
4.14
0
Coconut 1 tbsp (13.6 g)
117.23
13.6
11.76
0.79
0.25
0
Cottonseed 1 tbsp (13.6 g)
120.22
13.6
3.52
2.42
7.06
0
Corn 1 tbsp (13.6 g)
120.22
13.6
1.73
3.29
7.98
0
Olive 1 tbsp (13.5 g)
119.34
13.5
1.82
9.95
1.13
0
Palm 1 tbsp (13.6 g)
120.22
13.6
6.71
5.03
1.26
0
Palm Kernel 1 tbsp (13.6 g)
117.23
13.6
11.08
1.55
0.22
0
Peanut 1 tbsp (13.5 g)
119.34
13.5
2.28
6.24
4.32
0
Safflower 1 tbsp (13.6 g)
120.22
13.6
0.84
10.15
1.95
0
Soybean 1 tbsp (13.6 g)
120.22
13.6
1.96
3.17
7.87
0
Sunflower linoleic, >60% 1 tbsp (13.6 g)
120.22
13.6
1.4
2.65
8.94
0
Butter, Salted 1 pat (5g)+
35.85
4.06
2.52
1.17
0.15
10.95
Margarine, Corn 1 teaspoon (4.7 g)+
33.78
3.78
0.66
1.82
1.13
0
Source: United States Department of Agriculture (USDA) Nutrient Database for Standard Reference, Release 13+. Please note for comparison that the listed weight, in grams, of butter and margarine is significantly lower than that of selected oils. Consider these differences in weights carefully when making nutritional comparisons between these items.
Questions for your doctor
Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. You may wish to ask your doctor the following questions about reducing fat intake:
Do I have to avoid fatty foods entirely?
Will reducing the fat in my diet help me lose weight?
Is it safe for me to give my children a low fat diet?
Will my cardiac risk factor be passed on to my children?
What advice can you give me about eating out at restaurants?
Will my blood pressure improve with dietary changes?
Do all fats have cholesterol?
Are fat substitutes safe and effective?
What are trans-fats and do I need to limit them in my diet?