Is there a heart healthy diet? Do people lose more weight with a low fat or low carbohydrate diet? In the past few decades, thanks to Nathan Pritikin and Ancel Keys, fat phobia and heart health dominated nutrition advice. Even now, most people still think that high fat is associated with heart attacks. More recently our thinking about fats has changed – we now accept that not all fats are created equal in terms of health. The term “healthy fats” have entered the nutrition vocabulary. But what do we really know about the role of diet in heart disease, health and weight loss?
The old paradigm emphasized restriction of saturated fat and cholesterol but presently, that worn-out concept is being questioned. The requirement was that people eat less than 20% of calories as fat. The problem was exacerbated with low-fat products becoming loaded with sugar to compensate for this restriction and people were encouraged to eat carbohydrate with abandon whether it was healthy carbohydrate or not. For example, the old Food Guide Pyramid encouraged people to eat 6-11 servings of bread, cereal, rice and pasta a day. A controversial diet book called Calories Don’t Count even became a best seller. Although not the only factor, the obesity epidemic began during the decades of attempting to follow low-fat recommendations.
How does the latest trend of the low carbohydrate diet compare? Dr. Robert Atkins took the diet world by storm and people abandoned their egg white omelets for bacon and attempted to follow the Atkins Diet Revolution.A low-carb diet limits carbohydrates — such as those found in grains, starchy vegetables and fruit — and emphasizes foods higher in protein and fat. There are varying restrictions on the types and amounts of carbohydrates you can eat, but 50-100 grams is commonly accepted as reasonable carbohydrate restriction; however, there is no consistent definition of low carbohydrate.
The metabolic syndrome now gives us more of an idea of the factors that may contribute to heart disease. There are six parameters of this syndrome that have been identified that relate to heart disease: abdominal obesity, atherogenic dyslipidemia (low HDL, elevated LDL, high triglycerides) raised blood pressure, insulin resistance ± glucose intolerance, and a proinflammatory state. Along with age and lack of exercise, this syndrome risk increases even more.
In my opinion, the following statements reflect our current knowledge when we compare diets related to weight loss and/or our health.
- The jury is still out as to whether low fat or low carbohydrate diets play a role in heart disease directly. No one knows if sugar affects heart disease.
- The American Heart Association recommends a diet that emphasizes fruits, vegetables, whole grains, low-fat dairy products, poultry, fish and nuts. It limits red meat and sugary foods and beverages. This diet is very restrictive in that people cannot maintain it for very long due to restrictions on nutrient-dense foods like red meat and foods high in saturated fat and cholesterol.
- Low-fat diets high in polyunsaturated fats tend to lower LDL-cholesterol. Often HDL-cholesterol is decreased in the process.
- Initial weight loss is usually more rapid in the low carbohydrate approach, but over time, both low-fat and low carbohydrate result in modest weight loss (an average of about 10 pounds in 1 year according to most studies).
- Existing evidence suggests that carbohydrate restriction positively affects most of the components of the metabolic syndrome. Waistline is reduced, blood pressure is improved, triglycerides and HDL-cholesterol improve, there will be less insulin resistance, and glucose metabolism improves.
- Most people regain their weight loss within one to five years.
- A low carbohydrate diet is often a better choice for people with gastrointestinal problems since some carbohydrate foods contain components that aggravate some conditions like gluten sensitivity or irritable bowel syndrome.
- Whether it is a low fat or a low carbohydrate diet, both are restrictive. Overly restrictive diets don’t work since people find it difficult to maintain them since they take the pleasure out of eating. This can result in hunger, weight regain and the frustrating results of dieting failures.
What should you do either lose weight or improve your health? Commercial weight loss programs usually do not address the health aspects of diets; they only focus on weight loss. It is important to discuss your health profile with your doctor by looking at lipid and glucose lab results to decide which approach is best. People should choose their own diets based on their own personal metabolic profile, diet goals, and food preferences – think more of your health and less in terms of weight loss. Hopefully in the future, the diet wars will be resolved with more knowledge about the complexity of weight loss, weight maintenance as well as diet and health.
Perhaps, it may be best to not “diet” at all – more on this approach later.