It's the age-old question: which works better for weight loss, cutting out carbs or fat?
Thanks to a recent study, the plot has thickened. In a recent study conducted researchers at the National Institutes of Health, are claiming that low-fat diets are far more successful for losing weight than cutting out carbohydrates.
Researchers studied 19 obese people who consumed 2,700 calories a day.
Over two weeks their calorie intake was reduced by a third each day, either by reducing the amount of carbohydrates they consumed or the amount of fat.
Additionally, the team monitored the amount of oxygen and carbon dioxide that participants exhaled, as well as the amount of nitrogen in their urine, to calculate the chemical processes taking place inside their bodies.
Scientists found that those who reduced their fat intake lost more weight.
After six days on the diet, participants on a low-fat diet lost 463g of body fat (on average), which was 80% more than participants on a low-carb diet.
The study was published in the journal, Cell Metabolism.
Lead researcher, Dr Kevin Hall, from the National Institute of Diabetes and Digestive and Kidney Diseases, said that people looking to lose weight should stick to a diet that works for them.
"If it's easier to stick to one diet than another, and to ideally do it permanently, then you should choose that diet," he told BBC News.
"But if a low-fat diet is better for you, then you are not going to be at a metabolic disadvantage."
Scientists at McMaster University analysed 50 observational studies to look at whether there were links between saturated fats, trans fats and early mortality in adults.
They found that while trans fats are associated with greater risk of death and coronary heart disease, saturated fats are not.