According to a new study, egg consumption is not a significant risk factor for heart disease. Eating one egg a day contributes less than 1% of the risk of heart disease in healthy adults. Leila M. Barraj of Exponent's Health Sciences Center for Chemical Regulation and Food Safety in Menlo Park, Calif., said it was found in the study that poor diet, smoking, obesity and physical inactivity contribute 30-40% risk of heart disease. Hypertension and diabetes accounted for 60-70% risk.