The low-fat vs. low-carb diets is a never-ending battle. Science Daily reports that researchers with the National Institutes of Health claim that a low fat diet can help you get rid of more fat than a low-carb one. Their study showed that even when a low-carb diet reduced insulin and increased fat burning, restricting dietary fat promoted greater body fat loss than carb restriction.
The researchers wanted to rigorously test the hypothesis that restricting carbohydrate is particularly effective for losing body fat as this idea is the basis of many people’s decisions about their diets. To do this, they did what no study had done before – they measured what would happen if carbs were selectively cut from the diet while fat intake remained at a baseline or vice versa. Their model simulations showed that compared to a carb-restricted diet, a reduced-fat diet led to greater overall body fat loss. This led them to test the findings on a group of people.
The participants were 19 consenting adults who were obese but did not have diabetes. Their diet was closely monitored and controlled for a pair of 2-week periods. During the first period, fat intake was not altered while 30% of baseline calories were cut through carb restriction alone. The conditions were reversed in the second phase. The study found that:
- Body fat lost with dietary fat restriction was greater compared with carbohydrate restriction
- More fat was burned with the low-carb diet
- The reduced-carb dieters lowered their levels of insulin as well as lost slightly more weight than the reduced fat dieters, but those who cut fat actually lost more body fat than those who cut carbs. The lead researcher explains that this is because those on the low-fat diet saw a greater difference in the amount of fat they were eating and the amount of fat their bodies were burning compared to the carb-cutters.
These results are in contrast to a study conducted on 148 obese men and women by researchers from Tulane University in New Orleans and published last year in the Annals of Internal Medicine. It was found that those who followed a low-carb diet for one year lost 7.7 pounds more than those who ate less fat.
However, the lead researcher of this new 2015 study says that in these longer studies, one cannot be certain about whether the participants adhered to the prescribed proportions of carbohydrate and fat during the period of the study.
He says, “There is one set of beliefs that says all calories are exactly equal when it comes to body fat loss and there’s another that says carbohydrate calories are particularly fattening, so cutting those should lead to more fat loss. Our results showed that, actually, not all calories are created equal when it comes to body fat loss, but over the long term, it’s pretty close.
However, the present study has the limitation that it involved only 19 participants. On diet advice for lasting weight loss, the lead investigator recommends that the best diet is the one that you can stick to!