By Lisa Rapaport (Reuters Health) – Americans are adding more whole grains, nuts and seeds to their diets and cutting back on sodas and sugary drinks, a U.S. study suggests. While these changes point to some improvements in U.S. eating habits over the past decade, many people still consume too much sugar and processed food and not enough whole fruits and vegetables, the study published in JAMA found. “The overall diet is still far from optimal – less than one-third of American adults meet guidelines for most foods,” said senior study author Dr. Dariush Mozaffarian, dean of the Tufts Friedman School of Nutrition Science and Policy in Boston.