PARIS – A low carbohydrate diet could help obese people maintain their weight loss by increasing the number of calories their body is able to burn, experts said on Wednesday.
Presenting their findings at the International Obesity Week conference in Nashville, Tennessee, doctors reported that a low-carbohydrate diet could allow older overweight patients to live a healthier life by keeping pounds off.
Conventional treatment for obesity, which costs health services hundreds of billions of dollars a year, treats all calories – just eat less and your weight will be reduced.
However, several studies have shown that this calorie deficit decreases in the long run as a person's metabolism slows down energy conservation, making weight loss more difficult.
A team of researchers at the Boston Children's Hospital has tried a new approach, comparing the effects of diets that vary in carbohydrate to fat ratio over 20 weeks.
They tested 234 overweight adults who had a body mass index (BMI) of 25 or higher and placed them on an initial diet for weight loss for 10 weeks.
Those who achieved target weight loss randomly received diets ranging from 60% (high) to 20% (low) carbohydrates.
Participants in the low carbohydrate diet burn up to 278 calories a day more than those who are treated with high carbohydrate.
Writing in the BMJ medical journal, the authors said that this result, if retained, "would translate into an estimated loss of 10 pounds (22 pounds) after three years."
They said that the difference in calories burned may be particularly useful among people with high insulin production – those who suffer from diabetes or pre-diabetes – as it can help delay or compensate for hormone changes that increase hunger.
"These findings show that all calories are not the same as the body and that limiting carbohydrates may be a better strategy than limiting calories in the long run," said David Ludwig, endocrinologist at Boston Children's Hospital and co-author of studying.
"Calorie-free dietary composition has profound effects on hormones, metabolism and even the function of our genes." These results can make weight loss easier or tougher, and any weight lower or increase the risk of chronic illness. "
The World Health Organization reports that global obesity has tripled since 1975 and for the first time in human history there are more deaths linked to overweight than malnutrition.
Katarina Kos, senior lecturer in diabetes and obesity and Exeter University, said Wednesday's study raised questions about how the body metabolizes carbohydrates and whether it did so differently from other food groups.
"It is worth noting that the main metabolic rate was not different among the participants in the three diets and it remains unclear how to explain the difference in total energy expenditure," said Kos, who did not participate in the study.
"I am sure, however, to continue to propose a low (carbohydrate) diet to people with pre-diabetes."
The Obesity Week 2018 brings together more than 5,000 experts from around the world and is rebuilding on Thursday.