A new study from the University of Georgia shows that many of these products tend to be high in sugar content. When they mimicked the make-up of these foods and fed them to rat specimens, they found that it led to higher body fat mass, as well as liver damage and brain inflammation.
"Most so-called diet products containing low or no fat have an increased amount of sugar and are camouflaged under fancy names, giving the impression that they are healthy, but the reality is that those foods may damage the liver and lead to obesity as well," explains lead investigator and associate professor of veterinary biosciences Krzysztof Czaja.
Generating body fat
Over a four-week period, the researchers monitored three groups of rats – a group fed on a high-fat, high-sugar diet, a group fed on a low-fat, high-sugar diet, and a group fed on a “normal” or balanced diet. Caloric intake and body composition for all groups was tracked for the duration on the study.
After the test period concluded, the researchers found that the high-fat, high-sugar and low-fat, high-sugar groups showed increases in liver fat and significant increases in body weight and body fat when compared to the balanced diet group. Czaja pointed out that the increase in liver fat is especially concerning since it could lead to non-alcoholic fatty liver disease.
"What's really troubling in our findings is that the rats consuming high-sugar, low-fat diets didn't consume significantly more calories than the rats fed a balanced diet. Our research shows that in rats fed a low-fat, high-sugar diet, the efficiency of generating body fat is more than twice as high -- in other words, rats consuming low-fat high-sugar diets need less than half the number of calories to generate the same amount of body fat," Czaja said.
Permanent damage
Additional findings showed that the non-balanced diets induced chronic inflammation in the intestinal tract and brain, changes that could cause lasting and permanent harm. "The brain changes resulting from these unbalanced diets seem to be long term, and it is still not known if they are reversible by balanced diets," Czaja said.
Consumers looking to start a healthy diet should always consult with their doctor or nutritionist first to get the best advice. Some healthy staples that have passed the test of time include vegetables, fruits, whole grains, and certain fat-free or low-fat dairy products.
The full study has been published in Physiology & Behavior.