In studies of overweight patients who maintain weight loss, those who ate a low-carb diet consumed about 250 calories a day compared to high-carbohydrate diets.
The study of 164 people published by The BMJ Medical Journal on Wednesday pointed to the problem of maintaining weight loss in the face of hunger and metabolic stagnation as a result, and the caloric burning effect of the low-carb diet was " "
"This finding shows that calories are not all in the body and that limiting carbohydrates is a better strategy for long-term weight loss than limiting calories," said co-author David Ludwig . Balance Foundation Obesity Prevention Center at Boston Children 's Hospital.
This study deals with one of the worst problems in weight loss: As body weight falls, the body fights again, lowers calories, and blows us down with hunger signals.
Ludwig said, "The secret of failure."
It is also something of a mystery: why does the body react as if it is starving when it is not? For some researchers, including Ludwig, there is an answer to the carbohydrate-insulin model, the theory that treats carbohydrates such as white bread triggers hormone changes leading to hunger, metabolic deceleration and weight gain.
Processed carbohydrates are rapidly digested with sugar to increase insulin levels. Insulin programs fat cells in order to store excess calories in turn. When calories are trapped in obese cells, the brain does not recognize them and thinks the body needs more food.
The authors of the study, in collaboration with Framingham State University, agreed that 164 overweight students, faculty, and faculty would only eat the study meals. First, participants lost about 12% of their average weight, and the average participant lost about 20 to 25 pounds.
"I know that my metabolism is stressed," Ludwig said.
Then during the 20-week trial phase, participants were randomly assigned to three groups of 40% or 60% of those who had a diet consisting of 20% carbohydrates. Each diet contains 20% protein and the rest is composed of fat. The diet used healthy foods and was as similar as possible. The goal of this step was to keep weight loss and not lose weight any more.
Low-carbohydrate diet people drink 209-278 more calories a day than high-carbon diets, but if researchers do not intervene to maintain weight, they can lose 22 pounds over three years.
And the effect is greater for those who produce high levels of insulin in response to carbohydrates. They produced more than 308 to 478 calories per day in a low-carb diet.
How do you know if you are a high insulin secretagogue? Ludwig advised, "Look in the mirror." "If the fat distribution is mainly around the center – it's more like an apple than a pear – you're more likely to have high insulin secretion."
Dr Rudi Wigg said physical activity levels were very similar to the three diet groups before the study began.
Researchers encouraged all participants to maintain their daily level of physical activity, which was monitored. During the study, the low-carb group showed a tendency towards moderate active physical activity as a result of the diet, Ludwig said in an e-mail. But he emphasized that exercise is only a small part of the total effect on the calories burned.
The co-author of the 2015 PloS One journal article comparing low-fat and low-carb diets praised the accuracy and design of new studies, including direct calculation of energy consumption. This is difficult and labor intensive.
"I think they brought a level of sophistication that they could not see in this type of clinical trial." Jonathan Sackner-Bernstein Director of the Center for Technology and Innovation under the Food and Drug Administration is a drug counseling and device company.
Sackner-Bernstein said the study reinforced his belief that carbohydrate-sensitive individuals in terms of insulin response are more important in carbohydrate-limited diets.
Ludwig's research results are very similar to what the author predicted, but more research is needed.
"Because this is a study, the results need to be replicated and examined in more populations – we had a significant demographic change for participants." "We need to see how this research will affect other studies and how other people respond."