Dr. Jeffrey Browning of the University of Texas Southwestern Medical Center in Dallas said the findings, published in the journal Hepatology, could have implications for treating obesity and related diseases such as diabetes, insulin resistance and non-alcoholic fatty liver disease.
"Instead of looking at drugs to combat obesity and the diseases that stem from it, maybe optimizing diet can not only manage and treat these diseases, but also prevent them," Browning said in a statement.
The researchers randomly assigned 14 obese or overweight adults to either a low-carbohydrate or low-calorie diet and monitored seven lean subjects on a regular diet.
After two weeks, researchers used advanced imaging techniques to analyze the different methods, or biochemical pathways, the subjects used to make glucose.
Researchers found that participants on a low-carbohydrate diet produced more glucose from lactate or amino acids than those on a low-calorie diet.
People on a low-calorie diet got about 40 percent of their glucose from glycogen -- ingested carbohydrates stored in the liver until the body needs it.
The low-carbohydrate dieters, however, got only 20 percent of their glucose from glycogen. Instead of dipping into their reserve of glycogen, these subjects burned liver fat for energy, the study found.