Low-carb dieting trends have resurfaced again in recent years since the old Atkin’s diet fell out of fashion decades ago. However, new research is showing that low-carb diets are effective compared to high carb diets for weight-loss.
Boston Children’s Hospital conducted a study along with Framingham State University, and the findings showed that eating fewer carbs enabled the body to burn more calories. During the study called Framingham State Food Study, participants were given a controlled diet of prepared meals for 20 weeks that controlled their macronutrient levels and lowered their carbohydrate intake.
The researchers kept track of the weight and insulin levels of the participants throughout the study. They also noted levels of metabolic hormones and the number of calories participants burned. There were 234 overweight individuals who took part in the study, and 164 of them lost the target level of weight which was 10 to 14 percent of their body fat. Those who reached this goal went onto a maintenance phase to prevent weight gain.
There were three groups of participants, and each group was fed a different diet. The diets were classified as low, moderate and high carbohydrate variants. The group that ate the low-carb diet burned an average of 250 calories more per day than the group who ate the high-carb diet. Participants on the low-carb diet who had high insulin levels burned 400 more calories per day than those who ate the high-carb diet.
Researchers noted that the levels of the hormone ghrelin observed in the low-carb dieters were significantly lower than that of the high-carb dieters. This hormone is believed to inhibit calorie burning. Researchers also concluded that energy expenditures were greater during the maintenance phase of the program. This shows a benefit for obese people who have high insulin levels.
The Framingham State Food Study had more participants and longer duration than any previous study that tested carbohydrate intake in relation to insulin levels in overweight individuals. One of the lead researchers, David Ludwig, explained that processed carbohydrates raise insulin levels, and this causes fat cells to store more calories. Ludwig referred to previous decades as a “low-fat” era that led many people to become overweight.
When more energy is stored in fat cells, there is less energy available to fuel the body, and this causes signals of hunger to the brain that lead to overeating. The Framingham researchers have recently launched another diet study that compares carbohydrate and sugar intake, and the results are expected to be available in 2021.
There are numerous other studies that have shown similar positive results of people who eat low-carb diets. A study conducted in 2003 concluded that diabetic participants lost more weight on a low-carb diet than a group that merely restricted the calorie intake. A study conducted in 2005 tested substitution of carbohydrate-rich foods with fat or protein-rich foods to measure changes in blood pressure, lipid levels and cardiovascular health. This study also found positive results. Studies have also shown that a low-carb plant-based diet can provide lower risks of heart disease than high-carb diets.