At a time when Americans are getting fatter and struggle to find a strategy to combat the obesity epidemic, the rift between proponents of low fat vs low carb eating remains intact. Both philosophies have fans and detractors, but the mixed messages in the media create confusion about what truly is healthy for average individuals to consume. Obesity has been associated with an increased risk for diabetes, cardiovascular disease, several different cancers and premature death. So, finding the right remedy is more than just a matter of vanity and looking good in a swim suit, it is a matter of length and quality of life.
Low fat recommendations have been the mainstream message from such esteemed organizations as the American heart Association, the AMA and the USDA (creators of the food pyramid) among others. The logic behind this school of thought seems intuitive. Since increased blood lipids were associated with cardiovascular disease, and, cholesterol is a major component of arterial plaque, reducing dietary intake of saturated fats and cholesterol should remedy the situation. In addition, fat is more calorie dense than carbohydrates, so eliminating fats from the diet should reduce caloric intake and result in weight loss. There are, in fact, some clinical studies supporting the benefits of low fat diets on blood cholesterol levels and regression of arterial plaque. This philosophy has been questioned in recent years. An 8 year study of postmenopausal women eating a reduced fat diet over 8 years derived no significant benefit relative to cardiovascular disease, stroke, and coronary heart disease or CVD risk factors.[i] As logical as the low fat diet seemed intuitive is the question: if low fat was all it was purported to be, why over the last 30 years of low fat promoted diets and low-fat food products of every stripe, have Americans become more obese than ever, and cardiovascular disease remains the leading killer?
The answer is based more on indisputable physiology and nutrition science than intuition. Excess carbohydrates cause obesity, lead to insulin resistance, and signals the body to make and store more fats. High carbohydrate meals, particularly simple, easily absorbed carbs found in sugar, pasta, potatoes or anything made with white flour, stimulate the secretion of insulin. That insulin causes the carbs to be taken up by cells for energy but if not needed immediately, stored as fat. That rapid reduction in blood sugar causes hunger which leads to more carbohydrate ingestion and the cycle continues. As a result, blood cholesterol and triglyceride levels go up, thereby increasing cardiovascular risk. Earlier this month, a randomized comparative study of low carb and low fat diets concluded that weight loss was comparable between the two but only the low carb diet reduced cardiovascular risk parameters.[ii] Generally speaking, the low-carb approach is more satisfying and sustainable since it does not require limiting calories. The fat and protein content keep you feeling full longer obviating the need to count calories.
Is it just as simple as eating low carb? Of course not. No diet strategy taken to an extreme is good. Individauls metabolize food substrates differently. The diet that has most consistently been shown to reduce the risk of chronic diseases is a Mediterranean-style diet. It is not low fat nor strictly low carb. At Alternity Healthcare we make our recommendations are individualized and based on an extensive diet analysis, a thorough metabolic assessment and nutritional consultation with our registered dietician, Dr. Cassandra Forsythe. Here are some guidelines:
- Eat real food – something grown or has a parent. Something your grandparents would recognize as food.
- Eat healthy fats, such as omega-3 fats found in fatty fish (salmon, sardines), olive oil, nuts. Fats should comprise about 30% of calories.
- Consume most of your carbohydrates from colorful fruit and vegetables
- Eat lean grass-fed meats, free-range poultry and wild caught fish
- Avoid simple, refined carbohydrates, sugars and artificial sweeteners
- Avoid trans fats and processed foods
[i] Howard B, Van Horn L, et al. Low-Fat Dietary Pattern and Risk of Cardiovascular Disease. The Women’s Health Initiative Randomized Controlled Dietary Modification Trial JAMA. 2006;295:655-666
[ii] Foster G, Wyatt H, et al. Weight and Metabolic Outcomes After 2 Years on a Low-Carbohydrate Versus Low-Fat Diet. A Randomized Trial. Annals IM August 3, 2010 vol. 153 no. 3 147-157