Healthy, obese women who eat a low-carbohydrate diet can lose weight without negatively impacting their cardiovascular health in the short term, according to new research published in the April issue of The Journal of Clinical Endocrinology & Metabolism (JCE&M). The new study helps to better understand the short-term safety and effectiveness of widely popular low-carbohydrate diets, such as the Atkins diet.
As the epidemic of obesity has increased in the United States, the use of low carbohydrate diets, which lower dietary carbohydrate intake to less than 10 percent of daily caloric intake, has also increased. However, since low carbohydrate diets derive most of their calories from fat and protein, concerns about the cardiovascular safety of these diets have risen. According to the Centers for Disease Control and Prevention (CDC), cardiovascular disease, which includes high blood pressure, coronary heart disease, congestive heart failure and other condition, is the most common cause of death in the United States. In addition to measuring the cardiovascular safety, few studies have compared the weight loss success of very low carbohydrate diets to low-calorie, low-fat diets.
During a six month study, which is the longest randomized, controlled trial of these diets yet published, researchers at the University of Cincinnati compared the very low carbohydrate to the calorie-controlled, low fat diets and evaluated their impacts on cardiovascular factors in healthy, obese women.
The researchers divided 53 women over the age of 18 into two groups – one group was given a very low-carbohydrate diet and the other was given a calorie-restricted diet with 30 percent of calories from fat. At the end of six months, women on the low-carbohydrate diet lost more than double the weight and significantly more body fat than the women on the low-fat diet. Additionally, blood pressure, lipids, fasting glucose and insulin levels — all measurements of cardiovascular health — were within normal range at the beginning of the study and showed no changes after six months.
“Traditional healthy eating standards recommend fat intake of less than 30 percent to lower cholesterol and prevent obesity. Women in our study on the very low carbohydrate diet consumed more than 50 percent of their calories from fat. In the short term, this diet did not show a negative impact on the women’s cardiovascular health and caused weight loss. We were surprised by the unexpected results of our research,” said lead researcher Bonnie Brehm, PhD, RD, Assistant Professor in the College of Nursing at the University of Cincinnati. “Our findings lead to many more questions, however. This is a short-term study with a relatively small sample size. More research must be conducted to determine long-term effects of the low carbohydrate diet among larger and more diverse populations, such as persons with diabetes, heart disease, and other chronic diseases.”