Cutting the Fat out of Popular Nutrition Advice – An Update on Heart Healthy Eating

“Mark” is a pleasant 48 year old male who was referred to a local cardiologist for evaluation of his risk for heart disease.  During a recent annual visit with his primary care provider, Mark’s physician discovered that he has borderline elevated blood pressure, high cholesterol and prediabetes.  This was quite worrisome to Mark as his father developed heart disease at a young age of 52.  During his visit with the cardiologist, Mark stated that he had already initiated comprehensive changes to his less than ideal lifestyle, including following a low fat, low cholesterol diet.  However, was this the best dietary advice for Mark?  What about some of the trendy diets like Atkins, Ornish or South Beach?  What about commercial programs like Weight Watchers? 

When it seems like nutrition advice is changing almost weekly, it can be overwhelming to keep up with the latest recommendations.  Thankfully, and due to solid nutritional science, a few basic principles exist which have been consistently associated with heart health and longevity. 

Calories

Our bodies require a certain amount of energy (food) each day to perform all of the basic functions – eating, working, playing - even breathing.  The energy required to perform these activities can be expressed in calories.  Depending on age, gender, height and weight, a certain number of calories are required each day.  In Mark’s case, he needs to consume about 2,100 calories of food each day to provide his body with the necessary energy it needs to perform these basic functions.  If Mark consumes more food than this (i.e., more calories than his body needs), he will gain weight.  If he consumes less food than this (i.e., less calories than his body needs), he will lose weight.  Caloric balance is an important concept to understand, particularly when weight loss is recommended by a health care provider.  Reading food labels on packages, at grocery stores and at restaurants can help keep track of the number of calories being consumed.

Macronutrients

There are 3 main components to every diet: fat, carbohydrate and protein.  While the protein content of the “average” American diet is relatively fixed at about 20%, the fat and carbohydrate content can vary greatly.  In fact, it is the variation in fat and carbohydrate content which differentiates the various types of popular diets.

Fat

In the 1940’s and 1950’s, scientists discovered a strong link between fat in the diet and high cholesterol and heart disease.  Over the next 30-40 years, fat became a major target for heart disease prevention and treatment, and as a result, the overall fat content of the American diet dropped.  Since the % protein in the diet remained about the same, as the fat content dropped, carbohydrate consumption increased.  In the 1980’s and 1990’s, scientists realized that not all fat was the same, or bad.  We now know there are different types of fat, all of which have variable effects on our health.

 As a result of this new information, and for the past 20 years, scientists in the nutrition field have been trying to encourage Americans to cut out the bad (saturated and trans) fats, and increase the consumption of healthy (mono and polyunsaturated) fats.  Unfortunately, the “eat low fat foods to prevent heart disease” mantra persists in popular culture, as well as in many areas of the medical profession. 

Carbohydrates

As previously mentioned, when Americans were lowering their consumption of fat, they were increasing their consumption of carbohydrates.  Whereas in the early 1900’s when American diets consisted of carbohydrates rich in fiber and whole grains, over the past 50 years carbohydrate consumption has been characterized by foods made from refined, highly processed grains which are inherently low in fiber, vitamins and nutrients.  Increased consumption of these highly refined grains (and added sugars), over time, has contributed to the steady rise in overweight/obesity, diabetes and cardiovascular disease. 

Protein

Protein is an essential part of a healthy diet and is important for normal growth and development.  Protein can be found in many forms with variable effects on health.

Whereas plant-based sources of protein are consistently associated with health and longevity, animal sources have variable effects on health.  For example, fish has been associated with positive health, while processed meats (e.g., deli meats, hot dogs, sausage) have consistently been associated with poor health.  Poultry, eggs and moderate dairy have been shown to have a relatively health-neutral effect.  Finally, and somewhat controversial, unprocessed red meat has been found to have mostly negative effects on heart health.
 

Final Thoughts

While achieving and maintaining a healthy diet is essential for heart disease prevention and overall wellness, navigating the sea of diet/health information can be overwhelming.  Complicating matters is the fact that the diet/health industry is a $60 billion per year business, suggesting that people are willing to spend unprecedented amounts of money trying to achieve health.  Unfortunately, many of these efforts (and money spent) are unsuccessful.  Thankfully, there are a few basic nutritional principles which are grounded in solid science.  For our example patient, Mark, the following recommendations can be made:

• Be mindful of the calories you are eating each day.  Read nutrition fact labels on food products at grocery stores and at restaurants.  Eating more calories than your body needs will lead to weight gain.  Eating less calories than your body needs will lead to weight loss.
•  Don’t cut the fat out of your diet in an effort to be heart healthy.  Rather, choose to include healthy fats like mono- and polyunsaturated fats, while eliminating trans fat and minimizing saturated fat.   
• Exercise caution with carbs.  Diets high in refined grains and added sugars have been consistently associated with being overweight, obesity, diabetes and heart disease.  Alternatively, consuming whole grains rich in fiber can be a healthy part of a balanced diet. 
• Choose your protein wisely.  Add more plant based sources of protein, and choose more fish and poultry rather than red meat.

For those individuals who like to follow a specific dietary plan, the above dietary recommendations are mostly consistent with a Mediterranean style diet.  This type of eating pattern (lots of fruits, vegetables, legumes, whole (unprocessed) grains, yogurt/low fat dairy, nuts, fish, lean cuts of meat, olives and olive oil) has been consistently associated with a reduced risk for heart disease, cancer and premature death.