High-fat, high protein may be bad mix

DURHAM, N.C., April 8 (UPI) -- Diets high in fat have been shown to be bad for health, but diets high in fat and proteins may be even worse, U.S. researchers said.

Christopher Newgard of Duke Medical Center in Durham, N.C., reports that rats fed high-fat diets supplemented with extra so-called branched chain amino acids don't have to eat as much or gain as much weight to develop insulin resistance as do chubbier animals fed a high-fat diet alone.

Moreover, those ill effects of branched chain amino acids, which include three of the 20 amino acids that are the building blocks of proteins, occurred only in the context of a high-fat diet.

"We've all made a big deal out of the fact that people in the United States eat too much fat and sugar, but we've underestimated the protein component," Newgard said in a statement.

By comparing the metabolic profiles of obese versus lean people in the study, the researchers found that key among the many differences between the two groups were elevated levels of branched chain amino acids in those who were overweight.

The study, published in the journal Cell Metabolism, also showed that branched chain amino acids tend to climb along with insulin resistance, a condition that is a precursor to diabetes.