By Andrew M. Seaman NEW YORK (Reuters Health) – A new U.S. study adds to growing evidence that nuts – once considered too fattening to be healthy – may in fact help keep weight down, in addition to offering other health benefits. Researchers found that study participants who ate the most tree nuts – such as almonds, Brazil nuts, pistachios and walnuts – were between 37 and 46 percent less likely to be obese than those who ate the fewest tree nuts. People who ate the most nuts were also less likely to have a suite of risk factors known as metabolic syndrome, which is tied to increased risk of heart disease and diabetes. “This is another study that shows there is an association between eating nuts and not being obese and having less tendency to have metabolic syndrome,” Dr. Joan Sabaté told Reuters Health.