Weight loss diets that are low in carbohydrates have an advantage over low-fat diets for improving HDL cholesterol levels in the long term, according to a study by the National Institutes of Health.
People who followed low-carb or low-fat diet plans for two years along with a lifestyle modification program lost the same amount of weight — on average about 7% of their body weight or 15 pounds.
But throughout the two-year study, low-carbohydrate dieters had significantly higher HDL, or “good,” cholesterol levels compared to low-fat dieters.
Improvement for Heart-Risk Factors
For the first six months of the study, the low-fat dieters had a greater decrease in LDL, or “bad,” cholesterol. However, these differences did not persist over time.
The study is not the first to hint that low-carb weight loss programs such as the Atkins diet are safe and may be a bit better than low-fat diets for decreasing risk factors for heart disease.
But it is one of the longest to show this, states lead researcher Gary D. Foster, PhD, of Temple University’s Center for Obesity Research and Education.
Roughly 58 percent of the low-carb dieters and 68 percent of the low-fat dieters remained on their respective diets for two years.
“For many years there have been concerns that the low-carbohydrate approach to weight loss was bad for the heart,” he says. “This study would suggest those concerns are largely unfounded.”
Low-Carb Diets Can Be Heart-Healthy
A total of 307 obese people took part in the research, half of them following a low-carb diet and the other half following a low-fat diet.
The low-carb group was told to limit carbohydrates to 20 grams a day for three months, increasing their carb intake by 5 grams a week after that as long as they continued to lose weight.
As with the Atkins plan, these dieters ate mostly protein from meat sources during the induction phase along with about three cups of green leafy vegetables, Foster says.
The low-fat dieters were instructed to restrict their caloric intake to between 1,200 and 1,800 a day, with no more than 30 percent of those calories coming from fat.
Every participant attended group sessions aimed to motivate them to stay on the diets. The groups met weekly at first and then monthly toward the end of the study.
“The No. 1 thing was getting people to keep track of what they ate and their activities on a daily basis,” Foster says.
Other topics included limiting eating to specific places and times, managing the holidays, and getting back on track after overeating.
Even though HDL profiles were better in the low-carb group, Foster says dieters who successfully lost weight on both diets showed improvements in heart disease risk.
He says people who want to lose weight should pick a diet that is most likely to work for them.
“I think the main message is that people need to spend less time worrying about whether they should follow a weight loss diet that is low in this or high in that and spend more time learning strategies to help them stick to the diet they chose.
Why Extreme Diets Don’t Work
Weight loss researcher Frank M. Sacks, MD, of Harvard School of Health says the more extreme the diet, the less likely someone is to stick to it.
“Extremely low-carbohydrate diets may be safe, but people tend to get sick of them after a few months,” he says. “In this study, 42% of the low-carbohydrate dieters dropped out over time. They also reported more symptoms associated with the diet.”
Those symptoms included bad breath, constipation, and dry mouth.
He agrees that dieters should choose a weight loss plan they can stick to, with the goal being safe, gradual weight loss.
By following his own advice, Sacks was able to lose 15 pounds over nine months and keep it off.
“Half a pound a week may not sound like much, but over the course of a year that’s 24 pounds, which is huge,” he says.
REFERENCE: Salynn Boyles (2010) Low-Carb Diets Improve Cholesterol Long Term Retrieved from http://www.webmd.com/cholesterol-management/news/20100802/low-carb-diets-improve-cholesterol-long-term?ecd=wnl_hrt_081010