Reuters Health Information (2011-03-15): Short-term low-carb diet lowers hepatic triglycerides in NAFLD
Short-term low-carb diet lowers hepatic triglycerides in NAFLD
Last Updated: 2011-03-15 19:30:29 -0400 (Reuters Health)
NEW YORK (Reuters Health) - In patients with nonalcoholic fatty liver disease (NAFLD), a brief period of carbohydrate restriction reduced hepatic triglyceride levels more effectively than simple caloric restriction in a recent small study.
People with NAFLD have "increased rates of fat synthesis in the liver that really don't respond in a (normal) prandial manner," said lead author Dr. Jeffrey Browning of the University of Texas Southwestern Medical Center in Dallas in e-mail to Reuters Health.
In other words, he added, "They are constantly making fat in the liver."
Dr. Browning and colleagues thought limiting carbohydrate intake, rather than only caloric intake, would minimize fat synthesis and maximize fat oxidation in the liver.
"This is precisely what we saw after only two weeks of dietary intervention," he said.
As reported online March 2 in the American Journal of Clinical Nutrition, the 5 men and 13 women in the study were assigned "in a semi-random manner" to either a low-calorie diet (1200 to 1500 kcal/day) or a low-carb diet (less than 20 g/day).
All participants completed the 2 week study period, and all lost weight. The average weight loss was similar in the two groups - slightly more than 4 kg.
But while hepatic triglyceride content improved in both groups, it fell by 55% with the low-carb regimen (from 22% at baseline to 10% at 2 weeks) vs 28% with the low-calorie diet (from 19% to 14%; P=.008).
"Our approach is likely to only be of short-term benefit, because at some point the benefits of weight loss alone trounce any benefits derived from manipulation of dietary macronutrients," Dr. Browning said.
"The problem is that most people cannot make the lifestyle changes required, irrespective of the dietary approach," he added. "In our study, only 5% of the subjects maintained weight loss or continued to lose weight nine months after the study."
Am J Clin Nutr 2011.