With the grim prediction that 51% of the U.S. adult population will be obese by 2030, the U.S. Preventive Services Task Force released recommendations for obesity screening last month. Screening will lead to identification, and identification will lead to intervention. Intervention, hopefully, will lead to change.
Keep in mind that dramatic changes are not necessarily what is needed. A 5% to 10% reduction from baseline body weight is considered to be “metabolically significant” leading to reductions in the risk for diabetes and cardiovascular events.
A lot of heat and dim light currently surrounds the debate on the best diet advice for our patients who need to overhaul their approach to food consumption. A reduction in carbohydrates and overall caloric consumption both seem to be solid advice these days. But not all carbohydrates are the same (complex vs. refined), and an absolute carbohydrate reduction necessitates an increase in another energy source, such as protein. The most readily available sources of protein in our society are animals. But animal proteins, even if lean, may be associated with adverse cardiovascular outcomes.
Dr. Pagona Lagiou of University of Athens Medical School and Harvard School of Public Health and colleagues prospectively evaluated the cardiovascular risks associated with a low-carbohydrate, high-protein diet in 43,396 Swedish women (BMJ 2012;344:e4026). Participants were aged 30-49 years randomly selected to complete an extensive baseline dietary questionnaire and followed up for an average of 15.7 years. The investigators observed that a decrease in carbohydrate intake or an increase in protein intake or an increase in the “low carbohydrate-high protein score” were all significantly associated with an increasing incidence of cardiovascular disease.
Data further suggested that the incidence of cardiovascular events was higher among women whose protein intake was mainly of animal rather than plant origin.
If we are advising our patients to decrease carbohydrates and increase protein in order to lose weight, findings from this study would suggest that we include another important bit of information. First, dietary goals should aim to reduce simple carbohydrates (e.g., sucrose, high fructose corn syrup) more than complex carbohydrates (e.g., whole grains, fruits, and vegetables). Second, increases in protein consumption should aim to include more plant (e.g., spinach, soy, beans) than animal protein (e.g., lamb, beef, pork).
Key elements of this dietary approach are nicely embodied in the South Beach Diet. Most importantly, we need to emphasize to our patients that alterations in diet should not be considered a “diet” but a lifestyle change to improve overall health and well-being.
Jon O. Ebbert, M.D., is a professor of medicine and a primary care clinician at the Mayo Clinic in Rochester, Minn. He reports having no conflict of interest. The opinions expressed are solely those of the author. Contact him at ebbert.jon@mayo.edu.