"With the memory of Memorial Day cheeseburgers and bratwursts still lingering many of us may be relieved to hear that a new study suggests that a meaty highfat Atkinsstyle diet can do more than contribute to rapid weight loss. It may also be less unhealthy for the heart than many scientists had feared  provided you chase the sausage with a brisk walk.  It took people less time to lose  pounds on a highfat dietandexercise program about  days on average than the  days it took for those who exercised and followed a highcarbohydrate lowfat diet constructed using guidelines from the American Heart Association said Kerry J. Stewart director of clinical and research exercise physiology at Johns Hopkins University School of Medicine and lead author of the report. And at least in the short term there were no apparent harmful effects. The findings are being presented on Friday httpsstatic.nyt.compackagesflashhealthpdfACSM_.pdf at the annual meeting of the American College of Sports Medicine in Denver.  Such fatty lowcarbohydrate Atkinstype diets are well established as a means of successful weight reduction Dr. Stewart said. But a unique worry raised by these regimens extending back to the heyday of the original Atkins diet in the s was that indulging in repeated fatty glistening meals would lard your arteries and cause heart disease. In the current study participants followed a diet based on the New Atkins for Life approach which includes more vegetables than the original Atkins diet Dr. Stewart said adding that he and his colleagues have no ties to and receive no financing from the Atkins diet organization. To date however scientific data have been inconsistent. Some studies have reported that such diets contribute to cardiovascular disease while others found no increased risk. Few of the programs studied though included exercise. Hoping to bring some clarity to the issue the Johns Hopkins researchers recruited a group of  healthy but overweight men and women and randomly assigned half to a highcarbohydrate lowfat American Heart Associationapproved diet consisting of fruits grains vegetables and lowfat meats. The other  volunteers were assigned to a meatier cheesier highfat lowcarbohydrate spread with about  percent of calories derived from fat the diet avoided trans fats. Both approaches reduced volunteers normal daily caloric intake by about  calories.  The volunteers also began a supervised exercise program which included moderate endurance training likes brisk walking or jogging and weight lifting. The sessions lasted for at least  minutes three times a week.  At the start of the program the volunteers all had healthy blood vessels as determined by a bloodpressure cuff test in which researchers tighten the cuff release it and track the resulting gush of blood to the volunteers fingertips. During such a surge healthy vessels dilate or relax but unhealthy ones stiffen and narrow impairing blood flow and indicating possible incipient heart disease.  The researchers then waited for each person to lose  pounds. Retested with the blood pressure cuff the group eating the American Heart Associationstyle diet continued to display normal healthy blood flow. But so did the lowcarbohydrate highfat group. Their blood vessels dilated just as well as those eating a lowerfat diet. There was no evidence of any harmful vascular effects from the lowcarb diet Dr. Stewart said.  The results though come with several caveats. The study did not include a control group of men and women who performed no exercise making it impossible to tease out the exact physiological role that exercise played Dr. Stewart said.  And like most of the recent studies about the health effects of lowcarbohydrate diets these are very shortterm results said Dr. Dena Bravata an internist and research associate at the Center for Primary Care and Outcomes Research at Stanford University who was not involved with this experiment but has conducted dietary studies. Those on the highfat diets showed no harmful impacts after  days or so she said. But what about in  or  years if they remain on the diet  This study also reported on a single marker of cardiovascular health she continued. It would be nice to have information about whether peoples cholesterol and triglyceride levels changed she said.  The data being presented on Friday represent only interim results from a longerterm larger study Dr. Stewart pointed out. The full study will monitor the volunteers for six months and include additional measures of cardiovascular health after both diets.  Still the early results are thoughtprovoking. The volunteers all of whom exercised generally became more physically fit during the study Dr. Stewart said. Most increased their VO max a measure of maximal oxygencarrying capacity that is associated with lower cardiovascular disease risk.  They also lost substantial inches from their waistlines which may be an important consideration for heart health said Shane Phillips an assistant professor in the department of physical therapy at the University of Illinois at Chicago. In a study overseen by Dr. Phillips and published earlier this year https sedentary people on a lowcarbohydrate highfat diet lost pounds but few inches from around their middles. They also showed signs of impaired blood vessel health after six weeks on the diet. There seems to be something about fat around the waistline that negatively affects heart health even if someone loses weight with a highfat diet Dr. Phillips said. Dr. Stewart also has amassed some intimate anecdotal evidence. For a small pilot study several years ago he became a test subject adopting a lowcarbohydrate diet and regular exercise routine. For three years he has maintained both the diet and the workouts. He is  pounds lighter these days and he said continues to ace tests of his bloodvessel health."