(Reuters Health) – This year, dieters have told that calories are calories, but a new study suggests that humans can…
(Reuters Health) – This year, dieters have told that calories are calories, but a new study suggests that humans can burn more calories on a low carb diet than on a diet rich in carbohydrates.
“These findings showed that all calories do not resemble the body,” said the co-author of the study, Dr. David Ludwig, who encodes the New Balance Foundation Obesity Prevention Center at the Boston Children‘s Hospital. “Limiting carbohydrates can be a better strategy than limiting long-term calories.”
The new study did not focus on losing excess pounds, but rather on a factor that makes it difficult to maintain weight loss: the fact that the body adjusts as pounds are removed by lowering metabolism, resulting in fewer calories being burned. And for most it means that weight is recycled.
Ludwig subscribes to a theory called the carbohydrate insulin model, which indicates that the increase in consumption of so-called high-lymeemic foods ̵
1; which raises blood sugar sharply shortly after they have eaten – triggers hormonal changes that increase hunger and lead to weight gain.
To see if metabolism and hunger can be shifted by different types of foods that people eat, Ludwig and his colleagues 164 received overweight adults aged 18 to 65 who had already lost 10 percent of their body weight and randomly assigned them to one of three carb-varying diets for 20 weeks.
The volunteers provided by the researchers had the same daily calorie number and all contained 20 percent of protein. However, one group’s diet consisted of 20 percent fat and 60 percent carbohydrates, another received a 40 percent fat and 40 percent carbohydrate diet and the third group ate 60 percent fat and 20 percent carbohydrates.
After tracking the weight of volunteers and measuring energy consumption during the study period, it was clear that those who had consumed the lowest levels of carbohydrates had burned most calories. Perhaps equally important, their levels of the starvation hormones, ghrelin and leptin, were also lower.
Volunteers in the low-carb group burned 209 to 278 calories a day more than those on carbohydrates, which meant that they burned 50 to 70 calories more per day for every 10 percent reduction of carbohydrates to their total energy intake, according to the report in BMJ.
Volunteers with the highest insulin secretion at the beginning of the study had an even more dramatic difference in energy consumption: those on carbohydrates burned as much as 478 calories a day more than those consuming the highest carbohydrate levels.
This type of extra calorie burn would translate “to about 20 pounds of weight loss in one year among them on the low carb diet compared with those in the high carb group,” said Ludwig.
The new study is “exciting and unique,” says Dr. Rekha Kumar, a specialist on endocrinologist and obesity at New York Presbyterian and Weill Cornell Medicine in New York City. “Most studies are looking to induce weight loss,” said Kumar. “This is about weight loss. And that’s asking, is there a certain macro nutrient composition that can lead to a higher calorie burn?”
That people with higher insulin levels “had the greatest effect, you can say that this is quite valid” says Kumar, who was not involved in the study. “It’s because this is the people – those who have problems with blood sugar and insulin – that you expect to answer.”
The results hope that modifying nutrients in the diet could affect energy consumption, says Lisa Martich, a dietician specialist at Magee-Womens Hospital at the University of Pittsburgh Medical Center.
And it can finally be used as “another tool” in weight loss programs, said Martich, who was not involved in the study.
“I think there’s a tendency to go all or nothing, saying just eating a low carb diet and it will keep the weight off,” explained Kumar. “Maybe a low carb diet may help, but it can also increase the exercise.”
Source: bit.ly/2PFm3i0 BMJ, online November 14, 2018.
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