Heart-Healthy Diet Guidelines
The American College of Cardiology and American Heart Association latest joint dietary guidelines for reducing unhealthy cholesterol levels recommend:
- Make vegetables, fruits, and whole grains the focus of your diet
- Include low-fat dairy products, poultry, fish, legumes (beans), nontropical vegetable oils, and nuts
- Limit intake of sweets, sugar-sweetened beverages, and red meats
- Eat a balanced diet with plenty of high-fiber foods, such as fruits, vegetables, legumes, whole grains, and nuts. Reduce consumption of high-calorie, nutrient-poor foods and beverages.
- Limit daily consumption of foods saturated fats (found in red meat, butter, cheese and whole-fat dairy products) to less than 6% of total daily calories.
- Replace unhealthy saturated and trans fats with healthy unsaturated fats from plant and fish oils. Olive and canola oils are monounsaturated fats. Salmon and other fatty fish, as well as walnuts and other nuts, are excellent sources of polyunsaturated fats.
- Restrict your sodium (salt) intake. Reducing sodium is especially important for middle-aged and older people, African-Americans, and people with high blood pressure. The DASH diet is a good example of a heart-healthy eating plan that limits sodium intake.
- Choose nutrient-rich fruits instead of beverages and processed foods that contain added sugars. Limit your intake of sugar.
- If you drink alcohol, do so in moderation (1 drink per day for women, 2 drinks per day for men).
- Exercise regularly and include at least 40 minutes of moderate-to-vigorous exercise 3 to 4 times a week so that you burn at least as many calories as you consume to attain or maintain a healthy weight.
- Have your doctor create an individualized weight loss plan for you if you are overweight or obese. The plan should include a reduced calorie diet, behavioral strategies, and increased physical activity.
There is little evidence that multivitamin supplements help reduce the risk for heart disease or cancer, according to a 2014 recommendation from the United States Preventive Services Task Force. The agency specifically recommends against taking vitamin E or beta carotene supplements because there is conclusive evidence that they do not help prevent disease. Nutrient-rich foods (especially vegetables and fruits) are the best source for your vitamins.
The goals of a heart-healthy diet are to eat foods that help obtain or maintain healthy levels of cholesterol blood pressure. You can achieve this by:
- Reducing low-density lipoprotein (LDL), the "bad" cholesterol, which is harmful to the heart
- Reducing other harmful lipids (fatty molecules), such as triglycerides and increasing high-density lipoprotein (HDL), the "good" cholesterol
- Controlling blood pressure (blood pressure readings of 120/80 are considered normal, readings of 140/90 or higher indicate high blood pressure)
- Maintaining a healthy weight
The American Heart Association's (AHA) current dietary and lifestyle guidelines recommend:
- Balance calorie intake and physical activity to achieve or maintain a healthy body weight. (Controlling weight, quitting smoking, and exercising regularly are essential companions of any diet program. Try to get at least 40 minutes of moderate-intensity exercise on 5 or more days per week.
- Eat a diet rich in a variety of vegetables and fruits. Vegetables and fruits that are deeply colored (such as spinach, carrots, peaches, and berries) are especially recommended as they have the highest micronutrient content.
- Choose whole-grain and high-fiber foods. These include fruits, vegetables, and legumes (beans). Good whole grain choices include whole wheat, oats/oatmeal, rye, barley, brown rice, buckwheat, bulgur, millet, and quinoa.
- Include fish, poultry, low-fat dairy products, legumes, and nuts. Oily fish, such as salmon, mackerel, and sardines are rich in omega-3 fatty acids, which are heart protective. Limit intake of red meat. Grill, bake, or broil (do not fry!) using nontropical vegetable oils, such as olive or canola oil.
- Limit daily intake of saturated fat (found mostly in animal products) to less than 6% of total calories. Avoid trans fats (found in hydrogenated fats and oils, commercially baked products, and many fast foods).
- Use little or no salt in your foods. Reduce or avoid processed foods that are high in sodium (salt). Reducing salt can lower blood pressure and decrease the risk of heart disease and heart failure. The American Heart Association recommends a daily upper limit of no more than 2,400 milligrams (mg) a day. Further reduction to 1,500 mg a day (less than ¾ teaspoon of salt) is desirable for people with high blood pressure.
- Limit beverages and foods that contain added sugars (corn syrups, sucrose, glucose, fructose, maltose, dextrose, concentrated fruit juice, honey).
- If you consume alcohol, do so in moderation. The AHA recommends limiting alcohol to no more than 2 drinks per day for men and 1 drink per day for women.
Cholesterol is a soft, waxy substance that is present in parts of the body, including:
- The nervous system
It is made by the body and obtained from animal products in the diet. Cholesterol is made in the liver and is needed for normal body functions, including the production of hormones, bile acid, and vitamin D. Excessive cholesterol in the blood contributes to atherosclerosis and subsequent heart disease. The risk of developing heart disease or atherosclerosis increases as the level of blood cholesterol increases.
Fats and Oils
Some fat is essential for normal body function. Fats can have good or bad effects on health, depending on their chemistry. When it comes to reducing heart disease risk, the type of fat may be more important than the total amount of fat.
Monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) are "good" fats that help promote heart health. MUFAs and PUFAs should be the main type of fats consumed. Olive oil is rich in MUFAs. Salmon and walnuts are good sources of PUFAs.
Saturated fats and trans fats (trans fatty acids) are "bad" fats that can contribute to heart disease, and should be avoided or limited.
Current dietary guidelines for heart health recommend that:
- Total fat from all fat sources should be 25 to 35% of total daily calories.
- Monounsaturated fatty acids (found in olive oil, canola oil, peanut oil, nuts, and avocados) and omega-3 polyunsaturated fatty acids (found in oily fish, canola oil, flaxseed, and walnuts) should be the first choice for fats.
- Omega-6 polyunsaturated fatty acids (corn, safflower, sunflower, and soybean oils and nuts and seeds) are the second choice for fats. There has been controversy concerning linoleic acid, the main omega-6 fatty acid found in food. The American Heart Association supports the health benefits of omega-6 PUFAs and recommends that they be 5 to 10% of total calories as part of total fat intake.
- Limit saturated fat (found predominantly in animal products, including meat and whole-fat dairy products, as well as coconut, palm kernel and palm oils, and cocoa butter) to less than 6% of total daily calories.
- Limit trans fats (found in stick margarine, commercial baked goods, snack and fried foods) to less than 1% of total calories.
All fats, good or bad, are high in calories compared to proteins and carbohydrates. One fat gram provides 9 calories. The American Heart Association recommends choosing fats and oils that have less than 2 grams of saturated fat per tablespoon.
Try to replace saturated fats and trans fatty acids with unsaturated fats from plant and fish oils.
Omega-3 Fatty Acids: Omega-3 fatty acids, which are found in fish and some plant sources, are a good source of unsaturated fats. Fish oils contain the omega-3 fatty acids docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids, which have significant benefits for the heart. The American Heart Association recommends eating fatty fish such as salmon at least twice a week to gain a healthful amount of these omega-3 fatty acids.
Although eating fish appears to protect the heart, the effect of fish oil supplements is unclear. Some studies suggest these supplements are heart protective, but recent studies have indicated that omega-3 fatty acid supplements have minimal benefit. Still, patients with high triglycerides or heart arrhythmia may benefit from fish oil supplements, particularly if they do not consume enough fish in their diet.
Carbohydrates, Fiber, and Sugar
Carbohydrates are either complex (as in starches) or simple (as in sugars). One gram of carbohydrates provides four calories. The current general recommendation is that carbohydrates should provide 50 to 60% of the daily caloric intake. Many studies report that people can protect their heart and circulation by eating plenty of fruits and vegetables.
Complex Carbohydrates (Fiber): Complex carbohydrates found in whole grains and vegetables are preferred over those found in starch-heavy foods, such as pastas, white-flour products, and white potatoes. Most complex carbohydrates are high in fiber, which is important for health. Whole grains are extremely important for people with diabetes or those at risk for it.
Dietary fiber is an important component of many complex carbohydrates. It is found only in plants. Fiber cannot be digested by humans but passes through the intestines, drawing water with it, and is eliminated as part of feces content. The recommended daily intake of dietary fiber for heart protection is at least 25 grams for women and 38 grams for men ages 19 to 50. Older women and men need at least 21 and 30 grams of fiber, respectively.
Different fiber types may have specific benefits:
- Insoluble fiber (found in wheat bran, whole grains, seeds, nuts, legumes, and fruits and vegetables) may help achieve weight loss. Consuming whole grains on a regular basis may lower the risk for heart disease and heart failure, improve factors involved with diabetes, and lower the risk for type 2 diabetes. High consumption of nuts (such as almonds, macadamia, and walnuts) may be highly heart protective, independent of their fiber content.
- Soluble fiber (found in dried beans, oat bran, barley, apples, and citrus fruits) may help achieve healthy cholesterol levels and possibly reduce blood pressure as well.
- Soluble fiber supplements, such as those that contain psyllium or glucomannan, may also be beneficial. Psyllium is taken from the husk of a seed and is very effective for lowering total and LDL cholesterol. It is found in laxatives (Metamucil), breakfast cereals, and other products. People who increase intake of soluble fiber should also drink more water to avoid cramps.
Simple Carbohydrates (Sugar): Doctors recommend that no more than 10% of daily calories should come from sugar. (Currently, Americans eat nearly half a pound of sugar a day on average, and sugar intake constitutes 25% of a day's calories.) Sugars are usually one of two types:
- Sucrose. Source of most dietary sugar, found in sugar cane, honey, and corn syrup.
- Fructose. Found in fruits and vegetables. Although fructose does not appear to be have any different effects in the body than sucrose, most of the fruits and vegetables that contain it are important for good health. However, because fructose can raise triglyceride levels, people with high triglycerides should try to select fruits that are relatively lower in fructose (cantaloupe, grapefruit, strawberries, peaches, and bananas).
- A third sugar, lactose, is a naturally occurring sugar found in dairy products including yogurt and cheese.
High levels of sugar consumption, fructose or sucrose, are associated with higher triglycerides and lower levels of HDL ("good") cholesterol. The high consumption of sugar is contributing to our current obesity epidemic. Soda, other sweetened beverages, and fruit juice are major causes of childhood obesity.
The American Heart Association recommends eating nutrient-rich fruits and vegetables instead of sugar-sweetened beverages and food products with added sugars. Women should consume no more than 6 teaspoons (100 calories) of added sugar daily and men no more than 9 teaspoons (150 calories).
Be aware that nutrition labels on food packages do not distinguish between added sugar and naturally occurring sugar. Ingredients that indicate added sugars include:
- Corn sweetener
- Corn sugar
- High fructose corn syrup
- Fruit juice concentrates
- Any sugar molecules ending in "ose" (dextrose, fructose, glucose, lactose, maltose, sucrose).
Protein is found in animal-based products (meat, poultry, fish, and dairy) as well as vegetable sources such as beans, soy, nuts, and whole grains. In general, doctors recommend that proteins should provide 12 to 20% of daily calories. One gram of protein contains 4 calories. Protein is important for strong muscles and bones. The best sources of protein are fish, poultry, and soy. Restrict intake of red meat or any meat that is not lean.
Dietary Cholesterol: Animal-based protein contains dietary cholesterol. High amounts of dietary cholesterol occur in meat, whole fat dairy products, egg yolks, and shellfish. (Plant foods, such as fruits, vegetables, nuts, grains, do not contain cholesterol.) The American Heart Association recommends no more than 300 mg of dietary cholesterol per day for the general population and no more than 200 mg daily for those with high cholesterol or heart disease.
Fish: Fish is probably the best source of protein. Evidence suggests that eating moderate amounts of fish (twice a week) may improve triglyceride and HDL levels and help lower the risks for death from:
- Heart disease
- Dangerous heart rhythms
- Blood pressure
- A tendency for blood clots
The healthiest fish are oily fish such as salmon, mackerel, trout, sardines, or albacore ("white") tuna, which are high in the omega-3 fatty acids DHA and EPA. Most guidelines recommend eating fish at least twice a week. On average, three capsules of fish oil (preferably as supplements of DHA-EPA) are about equivalent to eating one serving of fish. However, some studies suggest that fish oil supplements are not as heart protective as dietary sources.
Women of childbearing age or nursing mothers should avoid fish that contains high amounts of mercury (such as shark, swordfish, golden bass, and king mackerel) and limit intake of tuna to 6 ounces/week. They should, however, try to eat at least 12 ounces/week of a variety of lower mercury-containing fish and shellfish (such as catfish, salmon, haddock, perch, tilapia, trout, crab, shrimp, and scallops). Most doctors agree that the benefits of fish intake (especially from low-mercury fish) outweigh the potential risks.
Soy: Soy is an excellent food. It is rich in both soluble and insoluble fiber, omega-3 fatty acids, and provides all essential proteins. Soy proteins have more vitamins and minerals than meat or dairy proteins. They also contain polyunsaturated fats, which are better than the saturated fat found in meat. The best sources of soy protein are soy products (tofu, soy milk, and soybeans). Soy sauce is not a good source. It contains only a trace amount of soy and is very high in sodium.
For many years, soy was promoted as a food that could help lower cholesterol and improve heart disease risk factors. However, it appears that soy protein and isoflavone supplement pills do not have a major effect on cholesterol or heart disease prevention. The American Heart Association still encourages patients to include soy foods as part of an overall heart healthy diet but does not recommend using isoflavone supplements.
Meat and Poultry: For heart protection, choose lean meat. Saturated fat in meat is the primary danger to the heart. The fat content of meat varies depending on the type and cut. It is best to eat skinless chicken or turkey. The leanest cuts of pork (loin and tenderloin), veal, and beef are nearly comparable to chicken in calories and fat as well as their effect on LDL and HDL levels. However, in terms of heart health, fish or beans are better choices.
Dairy Products: The best dairy choices are low-fat or fat-free products. Substituting low-fat dairy products can help lower blood pressure, reduce the risk for stroke, and lower the incidence of factors related to type 2 diabetes and heart disease (insulin resistance, high blood pressure, and unhealthy cholesterol).
Antioxidant Vitamins: Antioxidants are chemicals that act as scavengers of particles known as oxygen-free radicals (also sometimes called oxidants). Vitamins E and C have been studied for their health effects because they serve as antioxidants. High intake of foods rich in these vitamins (as well as other food chemicals) are associated with many health benefits, including prevention of heart problems.
However, despite much research, there is little evidence that regular use of multivitamin supplements reduces the risk for heart disease. And, in fact, there is conclusive evidence that supplements of vitamin E and beta-carotene do not help protect against heart disease. Supplements of vitamin E, vitamin C, and beta-carotene are not recommended as part of a heart-healthy diet. Food rich in these nutrients is recommended.
B Vitamins (Folic Acid): Deficiencies in the B vitamins folate (known also as folic acid), B6, and B12 have been associated with a higher risk for heart disease in some studies. Such deficiencies produce higher blood levels of homocysteine, an amino acid that has been associated with a higher risk for heart disease, stroke, and heart failure.
While major studies have indicated that B vitamin supplements help lower homocysteine levels, they do not protect against heart disease, stroke, or dementia (memory loss). Homocysteine may be a marker for heart disease rather than a cause of it.
Vitamin D: Vitamin D, in addition to promoting bone health, may also be important for heart health. In studies, people who were vitamin D deficient appeared to have an increased risk for heart-related deaths. Other studies have suggested that children and adolescents who have low blood levels of vitamin D may be at increased risk of developing heart disease and diabetes. More research is needed.
Dietary sources of vitamin D include fatty fish (such as salmon, mackerel, and tuna), egg yolks, liver, and vitamin D-fortified milk, orange juice, or cereals. Sunlight is also an important source of vitamin D. However, many Americans do not get enough vitamin D solely from diet or exposure to sunlight and may require supplements.
At this time, there is no standard recommendation for whether people should take vitamin D supplements for heart health, or at what dosages. Many doctors recommend that for bone and overall health, children and teenagers should get at least 400 IU of vitamin D daily, adults under age 50 should get 400 to 800 IU daily, and adults over age 50 should get 800 to 1,000 IU daily.
Potassium: A potassium-rich diet can provide a small reduction in blood pressure. Potassium-rich foods include:
- Dried peas and beans
Potassium supplements should not be taken by patients without checking with your doctor first. For those using potassium-sparing diuretics (such as spironolactone), or have chronic kidney problems, potassium supplements may be very dangerous.
Magnesium: Some studies suggest that magnesium supplements may cause small but significant reductions in blood pressure. The recommended daily allowance of magnesium is 320 mg. People who live in soft water areas, who use diuretics, or who have other risk factors for magnesium loss may require more dietary magnesium than others.
Calcium: Calcium regulates the tone of the smooth muscles lining blood vessels. Studies have found that people who consume enough adequate dietary calcium on a daily basis have lower blood pressure than those who do not. Consuming too much dietary calcium may, however, have a negative effect.
Some sodium (salt) is necessary for health, but the amount is vastly lower than that found in the average American diet. High salt intake is associated with high blood pressure (hypertension). Everyone should restrict their sodium intake. Limiting sodium can help lower blood pressure and may also help protect against heart failure and heart disease.
The American Heart Association recommends limiting sodium intake to no more than 2,400 mg a day. People with high blood pressure (hypertension) or other heart disease risk factors should consider an upper sodium limit of no more than 1,500 mg a day.
Some people (especially African-Americans, older adults, people with diabetes, and people with a family history of hypertension) are "salt sensitive," which means their blood pressure responds much more to salt than other people. People with salt sensitivity have a higher than average risks of developing high blood pressure as well as other heart problems. Sodium restriction is particularly important for people with salt sensitivity, as well as those with diagnosed hypertension.
Simply eliminating the use of salt at the table eating can help. But it is also important to reduce or avoid processed and prepared foods that are high in sodium. Spices can be used in place of salt to enhance flavor.
Salt substitutes, such as Nu-Salt and Mrs. Dash (which contain mixtures of potassium, sodium, and magnesium), are available, but they can be risky for people with kidney disease or those who take blood pressure medication that causes potassium retention. For people without risks for potassium excess, adding potassium-rich foods to a diet can help.
Here are some tips to lower your sodium (salt) intake:
- Look for foods that are labeled "low-sodium," "sodium-free," "no salt added," or "unsalted." Check the total sodium content on food labels. Be especially careful of canned, packaged, and frozen foods. A nutritionist can teach you how to understand these labels.
- Do not cook with salt or add salt to your food. Try pepper, garlic, lemon, or other spices for flavor instead. Be careful of packaged spice blends as these often contain salt or salt products (like monosodium glutamate, or MSG).
- Avoid processed meats (particularly cured meats, bacon, hot dogs, sausage, bologna, ham, and salami). Processed meats have been associated with increased risk for heart disease, type 2 diabetes, and an increased death rate.
- Avoid foods that are naturally high in sodium, like anchovies, nuts, olives, pickles, sauerkraut, soy and Worcestershire sauces, tomato and other vegetable juices, and cheese.
- Take care when eating out. Stick to steamed, grilled, baked, boiled, and broiled foods with no added salt, sauce, or cheese.
- Use oil and vinegar, rather than bottled dressings, on salads.
- Eat fresh fruit or sorbet when having dessert.
Water: People with certain medical conditions, (such as heart failure), that cause fluid retention may need to restrict their intake of water and other fluids.
Alcohol: A number of studies have found heart protection from moderate alcohol intake (one or two glasses a day). Although red wine is most often cited for healthful properties, any type of alcoholic beverage appears to have similar benefit.
However, alcohol abuse can increase the risk of high blood pressure and many other serious problems. Men should limit their intake to an average of no more than one or two drinks a day, and women (especially those at risk for breast cancer) and thinner people should only have one drink a day. (A "drink" is equivalent to a 12-ounce bottle of beer, a 5-ounce glass of wine, or a 1.5-ounce shot of hard liquor.)
Overuse of alcohol can also lead to many heart problems. People with high triglyceride levels should drink sparingly if at all because even small amounts of alcohol can significantly increase blood triglycerides. Pregnant women, people who can't drink moderately, and people with liver disease should not drink at all. People who are watching their weight should be aware that alcoholic beverages are very high in calories.
Coffee and Tea: Coffee drinking is associated with small increases in blood pressure, but the risk it poses is very small in people with normal blood pressure. Moderate coffee consumption (1 to 2 cups a day) poses no heart risks and long-term coffee consumption does not appear to increase the risk for heart disease in most people, even if they consume large daily amounts.
Although both black and green tea contain caffeine, they are safe for the heart. Tea contains chemicals called flavonoids that may be heart protective.
There are many dietary approaches for protecting heart health, such as the Mediterranean Diet, which emphasizes fruits, vegetables, and healthy types of fats. The DASH diet is very effective for patients with high blood pressure and others who need to restrict sodium (salt) intake. Other heart-healthy diet plans include the American Heart Association diet and the USDA Food Pattern.
Try to focus on eating a balanced meal full of nutrient-rich foods. Vegetables and fruits provide the most nutrients and fiber, and the fewest calories.
The Mediterranean diet is rich in heart-healthy fiber and nutrients, including omega-3 fatty acids and antioxidants. The diet consists of fruits, vegetables, and unsaturated "good" fats, particularly olive oil.
Olive oil may:
- Help lower blood pressure
- Lower risk for heart disease
- Possibly have specific benefits for people with type 2 diabetes
Olive oil contains monounsaturated fatty acids (MUFAs) and also contains polyphenols, which are phytochemicals that contain antioxidant properties.
Virgin olive oil comes from a simple pressing of the fruit. Extra-virgin olive oil is a superior tasting form of virgin olive oil. Non-virgin olive oils are produced using chemical processes. For health purposes, it is best to use extra-virgin or virgin olive oil.
There are several variations to the Mediterranean diet, but general recommendations include:
- Limit red meats.
- Drink 1 or 2 glasses of wine each day if alcohol is enjoyable and there are no reasons to restrict its use.
- Limit whole fat dairy products.
- Eat moderate amounts of fish and poultry. Fish is the diet's main protein source.
- Eat plenty of fresh fruits and vegetables, nuts, legumes, beans, and whole grains.
- Season foods with garlic, onions, and herbs.
- Use extra-virgin or virgin olive oil.
Even though fats make up about 40% of the calories found in the traditional Mediterranean diet, they are mostly unsaturated. Growing evidence continues to support the heart-protective properties of the Mediterranean diet. Research has shown that such a diet prevents heart disease, reduces the risk for a second heart attack, and helps cholesterol-lowering statin drugs work better. (Despite claims, garlic does not help lower LDL "bad" cholesterol, though it adds flavor to many Mediterranean recipes.)
Older adults who combine a Mediterranean diet with healthy lifestyle habits have been found to live longer lives. Many studies confirm that the Mediterranean diet is as good as or better than a low-fat diet for preventing heart attack, stroke, or other heart events.
The salt-restrictive DASH diet (Dietary Approaches to Stop Hypertension) is proven to help lower blood pressure, and may have additional benefits for preventing heart disease, stroke, and heart failure. Effects on blood pressure are sometimes seen within a few weeks. This diet is rich in important nutrients and fiber. It also provides far more potassium (4,700 mg/day), calcium (1,250 mg/day), and magnesium (500 mg/day), but much less sodium, than the average American diet.
DASH diet recommendations:
- Limit sodium (salt) intake to no more than 2,300 mg a day (some people may benefit from reducing sodium intake to no more than 1,500 mg a day).
- Reduce saturated fat to no more than 6% of daily calories and total fat to 27% of daily calories. (But, include calcium-rich dairy products that are non- or low-fat.)
- When choosing fats, select monounsaturated oils, such as olive or canola oils.
- Choose whole grains over white flour or pasta products.
- Choose fresh fruits and vegetables every day. Many of these foods are rich in potassium, fiber, or both, which may help lower blood pressure.
- Include nuts, seeds, or legumes (dried beans or peas) daily.
- Choose modest amounts of protein (no more than 18% of total daily calories). Fish, skinless poultry, and soy products are the best protein sources.
- Other daily nutrient goals in the DASH diet include limiting carbohydrates to 55% of daily calories and dietary cholesterol to 150 mg. Patients should try to get at least 30 g of daily fiber.
Low Carbohydrate Diets
Low carbohydrate diets generally restrict the amount of carbohydrates but do not restrict protein sources.
The Atkins diet restricts complex carbohydrates in vegetables and, particularly, fruits that are known to protect against heart disease. The Atkins diet also can cause excessive calcium excretion in urine, which increases the risk for kidney stones and osteoporosis.
Low-carbohydrates diets, such as South Beach, The Zone, and Sugar Busters, rely on a concept called the "glycemic index," or GI, which ranks foods by how fast and how high they cause blood sugar levels to rise. Foods on the lowest end of the index take longer to digest. Slow digestion wards off hunger pains. It also helps stabilize insulin levels. Foods high on the glycemic index include bread, white potatoes, and pasta, while low-glycemic foods include whole grains, fruit, lentils, and soybeans.
There has been debate about whether Atkins and other low-carbohydrate diets can increase the risk for heart disease, as people who follow these diets tend to eat more animal-saturated fat and protein and less fruits and vegetables. In general, these diets appear to lower triglyceride levels and raise HDL ("good") cholesterol levels. Total cholesterol and LDL ("bad") cholesterol levels tend to remain stable or possibly increase somewhat. However, large studies have not found an increased risk for heart disease, at least in the short term. In fact, some studies indicate that these diets may help lower blood pressure.
Low-carbohydrate diets help with weight loss in the short term, possibly better than diets that allow normal amounts of carbohydrates and restrict fats. However, overall, there is not good evidence showing long-term efficacy for these diets. Likewise, long-term safety and other possible health effects are still a concern, especially since these diets restrict healthy foods such as fruit, vegetables, and grains while not restricting saturated fats.
Dietary guidelines recommend keeping total fat intake to 20 to 30% of total daily calories, with saturated fat less than 10% of calories. Very low-fat diets generally restrict fat intake to 20% or less of total daily calories. The Ornish program, recommended for some heart disease patients, limits fats even more drastically. It aims to reduce saturated fats as much as possible, restricting total fat to 10%, and increasing carbohydrates to 75% of calories.
The Ornish program is a very demanding regimen:
- It excludes all oils and animal products except nonfat yogurt, nonfat milk, and egg whites.
- It emphasizes whole grains, legumes, and fresh fruits and vegetables.
- People in the program exercise for 90 minutes at least three times a week.
- Stress reduction techniques are used.
- People do not smoke or drink more than two ounces of alcohol per day.
Benefits of Low-Fat Diets; Low-fat programs may help keep weight off. Low-fat diets that are high in fiber, whole grains, legumes, and fresh produce offer health advantages in addition to their effects on cholesterol. These foods are also lower on the glycemic index than high-glycemic foods, such as bread, potatoes, and pasta. Lowering the glycemic index (by, for example, cutting down on starchy vegetables and replacing pasta with whole grains) may help increase weight loss and heart benefits for high-carbohydrate diets.
While claims regarding a significant reduction in angina and even reduction in coronary artery stenosis have been made by the Ornish program directors, actual regression in atherosclerosis or prevention of heart disease has only been shown in a small number of patients.
Concerns Regarding Low-Fat Diets; The American Heart Association notes that the Ornish program is so difficult to maintain that most people have difficulty staying with it. Very low-fat diets reduce HDL ("good") cholesterol levels. These diets may also reduce calcium absorption, which can be harmful for women at risk for osteoporosis. Many people who reduce their fat intake do not consume enough of the basic nutrients, including vitamins A, D, E, calcium, iron, and zinc. People on low-fat diets should eat a wide variety of foods and take a multivitamin if appropriate.
Calorie restriction has been the cornerstone of weight-loss programs. Restricting calories also appears to have beneficial effects on cholesterol levels, including reducing LDL and triglycerides and increasing HDL levels. A 5 to 10% decrease in body weight can result in a 20% decrease in triglyceride levels. In general, reducing calories and increasing exercise is still the best method for maintaining weight loss and preventing serious conditions, notably diabetes.
The standard dietary recommendations for losing weight are:
- As a rough rule of thumb, one pound of fat contains about 3,500 calories, so one could lose a pound a week by reducing daily caloric intake by about 500 calories a day. The more severe the daily calorie restriction, the faster the weight loss.
- To determine the daily calorie requirements for specific individuals, multiply the number of pounds of ideal weight by 12 to 15 calories. The number of calories depends on gender, age, and activity levels. For example, a 50-year-old woman who wants to maintain a weight of 135 pounds and is mildly active might require only 12 calories per pound (1,620 calories a day). A 25-year-old female athlete who wants to maintain the same weight might require 25 calories per pound (2,025 calories a day).
- Fat intake should be no more than 30% of total calories. Most fats should be in the form of monounsaturated fats (such as olive oil). Avoid saturated fats (found in animal products).
A healthy weight is very important for healthy cholesterol levels. For people who are overweight or obese, losing even a modest amount of weight has significant health benefits, even if an ideal weight is not achieved. There is a direct relationship between the amount of weight lost and an improvement in cholesterol.
In particular, triglyceride is closely linked to weight: a sustained 3 to 5% weight loss can significantly reduce unhealthy triglyceride levels. Even greater amounts of weight loss can help improve LDL ("bad" cholesterol) and HDL ("good" cholesterol) levels. Weight loss also helps reduce the need for blood pressure medication, improve blood glucose (sugar) levels, and lower the risk for developing type 2 diabetes.
Obesity is now considered and treated as a disease, not a lifestyle issue. Doctors' understanding of weight issues has evolved. Scientific evidence has shown that weight gain is a complex process, and weight loss involves more than simple will power. What is clear is that excess weight contributes to many health problems, including increased risks for cardiovascular disease conditions.
Your doctor should check your body mass index (BMI) at least once a year. The BMI estimates how much you should weigh based on your height:
- Overweight is a BMI of 25 to 29.9
- Obese is a BMI of over 30
Guidelines recommend your doctor create an individualized weight loss plan for you if you are overweight or obese. The plan should include three components:
- Reduced calorie diet. Your doctor should help you select an eating plan that will cut calories and perhaps restrict certain food types (such as fats or carbohydrates). Your doctor may make specific recommendations depending on your cholesterol profile and other factors. For example, a low-calorie, low-fat diet can be very effective for reducing LDL levels. (Your personal and cultural food preferences should also be considered.) Your doctor may refer you to a registered dietician or nutritionist for counseling.
- Behavioral Strategies. Patients need to consider how to set weight loss goals, monitor weight, track food and calorie intake, change shopping habits and food storage environments, and establish fitness routines. Patients may benefit from individual, group, or telephone counseling sessions.
- Increased Physical Activity. Patients should aim for 200 to 300 minutes of physical activity a week (about 40 minutes a day of moderate to intensive aerobic exercise).
A weight loss of 5 to 10% within the first 6 months of starting these changes can help improve cholesterol levels and other health indicators. If you have risk factors for heart disease or diabetes and do not achieve weight loss from diet and lifestyle changes alone, your doctor may recommend adding a prescription medication to your weight loss plan. For patients who have a very high BMI and several cardiovascular risk factors (such as diabetes and high blood pressure), bariatric surgery may be considered.
Guidelines for Weight Loss
Lifelong changes in eating habits, physical activity, and attitudes about food and weight are essential to weight management. Unfortunately, although many people can lose weight initially, it is very difficult to maintain weight loss. Here are some general suggestions that may be helpful:
- Start with realistic goals. When overweight people achieve even modest weight loss they reduce risk factors in the heart.
- A regular exercise program is essential for maintaining weight loss. If there are no health prohibitions, choose one that is enjoyable. Check with a doctor about any health consideration.
- Do not take hunger pangs as cues to eat. A stomach that has been stretched by large meals will continue to signal hunger for large amounts of food until its size reduces over time with smaller meals.
- Be honest about how much you eat, and track calories carefully. People who do not carefully note everything they eat tend to take in excessive calories.
- Once a person has lost weight, maintenance is required. To maintain a healthy weight, make careful decisions about how many calories you consume in food and how many calories you expend through physical activity. Such thinking will eventually become automatic.
Inactivity is a major risk factor for coronary artery disease, on par with smoking, unhealthy cholesterol, and high blood pressure. In fact, studies suggest that people who change their diet in order to control cholesterol lower their risk for heart disease only when they also follow a regular aerobic exercise program. Exercise also helps improve blood pressure and blood sugar (glucose) levels.
The American Heart Association’s current guidelines recommend regular physical activity (at least 30 minutes) every day, and at least 40 minutes of moderate-to-vigorous exercise 3 to 4 times a week.
Research strongly supports the benefits of exercise on coronary artery disease:
- People who maintain an active lifestyle have a significantly lower risk of developing heart disease than do sedentary people. Even moderate exercise reduces the risk of heart attack.
- People who lose weight and exercise regularly have a much better chance of maintaining weight loss compared to those who do not exercise.
- Burning at least 250 calories a day (the equivalent of about 45 minutes of brisk walking or 25 minutes of jogging) appears to offer the greatest protection against coronary artery disease, particularly by raising HDL ("good" cholesterol) levels.
- Aerobic exercise may help open up blood vessels and, in combination with a healthy diet, may improve blood-clotting factors.
- Resistance (weight) training offers a complementary benefit by reducing LDL (bad cholesterol) levels.
- www.heart.org -- American Heart Association
- www.acc.org -- American College of Cardiology
- www.nhlbi.nih.gov -- National Heart, Lung, and Blood Institute
- www.eatright.org -- Academy of Nutrition and Dietetics
- http://fnic.nal.usda.gov -- Food and Nutrition Information Center
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Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team. Author: Julia Mongo, MS. A.D.A.M.