Pounding the pavement or moving tin might sound like the only way to burn calories, but your diet also plays a crucial role in metabolism. And now new research has confirmed one diet sticks out when it comes to increasing calorie expenditure.
According to a new study orchestrated by Boston Children's Hospital, in partnership with Framingham State University, eating fewer carbs actually increases the number of calories burned.
Over a 20-week period, scientists provided 234 overweight (body mass index of 25 or higher) participants aged between 18 and 65 with prepared food-service meals.
Weight was carefully tracked while insulin secretion, metabolic hormones and the amount of calories burned were all measured.
Initially the program went for 10 weeks. After reaching this mark, 164 volunteers hit their goal of losing 10 to 14 per cent of body weight. They continued on to the maintenance phase of the study.
"This is the largest and longest feeding study to test the 'Carbohydrate-Insulin Model,' which provides a new way to think about and treat obesity," says Dr. David Ludwig, co-investigator of the study.
"According to this model, the processed carbohydrates that flooded our diets during the low-fat era have raised insulin levels, driving fat cells to store excessive calories. With fewer calories available to the rest of the body, hunger increases and metabolism slows -- a recipe for weight gain."
In the second part of the experiment, participants followed randomised high, moderate or low-carbohydrate diets for an additional 20 weeks. Carbohydrate intake comprised of 60,40 and 20 per cent of total calories, respectively.
Researchers ensured that the carbohydrates provided were high quality. Total calorie intake was modified to maintain weight loss.
The aim of the investigation was to see how groups consuming different amounts of carbs affected energy expenditure. Interestingly, participants on low-carbohydrate diets burned the most calories compared to their high-carb counterparts.
"If this difference persists -- and we saw no drop-off during the 20 weeks of our study -- the effect would translate into about a 20-pound weight loss after three years, with no change in calorie intake," adds Dr. Cara Ebbeling.
Other health factors affect the outcome to: in people with the highest insulin secretion, calorie expenditure was greater between low and high-carb diets.
"Our observations challenge the belief that all calories are the same to the body," continues Ebbeling.
"Our study did not measure hunger and satiety, but other studies suggest that low-carb diets also decrease hunger, which could help with weight loss in the long term."
Like anything, if you suffer from any health-related issues, it's always important to check-in with your GP before starting a new program.