According to a recent study published in the Archives of Internal Medicine, those that followed a low-carb diet lost as much weight as those who followed a low-fat diet and also took a popular weight-loss drug called orlistat (marketed as Xenical in a prescription form and Alli, as an over-the-counter drug). The study found that while both diets helped participants lose about ten percent of their body weight, those on the low-carb diet had greater reductions in their blood pressure levels than the study volunteers on the low-fat diet.

The study included 146 overweight or obese adults with an average body mass index (BMI) of 39 (a BMI of over 25 is considered overweight and a BMI of over 30 is considered obese). Study volunteers on the low-carb diet took in less than 20 grams of carbohydrates a day and the orlistat group received a 120-milligram dose of the drug three times a day and got less than 30 percent of their calories from fat.

After nearly a year in the study, those in the low-carb group lost 9.5 percent of their body weight and the orlistat group lost 8.5 percent. Both groups saw an improvement in their HDL ("good") cholesterol levels, although the LDL ("bad") cholesterol levels were only reduced in the orlistat group. However, only the low-carb dieters saw improvements in their insulin and glucose markers as well as a significant drop in their blood pressure levels: 5.9 mm Hg (systolic reading, top number) compared to just 1.5 mm Hg for the orlistat group. Similar reductions were seen in the diastolic blood pressure (bottom number).

A low-carb diet limits the amount of carbohydrates you eat, for example, bread, grains, rice, starchy vegetables and fruit, and emphasizes sources high in protein and fat, including meat, poultry, fish, dairy products and eggs. However, it's unclear what the long-term health benefits or risks are of eating a low-carb diet.

If you're concerned about high blood pressure, ask your doctor if the DASH (Dietary Approaches to Stop Hypertension) eating plan might be a better solution for you. The DASH diet, which includes a diet rich in fruits, vegetables, low-fat foods and lean meats, fish and poultry, is recommended by the American Heart Association and the National Heart, Lung and Blood Institute and has been proven to lower blood pressure in just 14 days. Research also shows that the DASH diet reduces the risk of stroke and heart disease.