A new study has found that following a diet that consists of processed foods can quickly result in weight gain. The study by a team of researchers at the National Institute of Diabetes and Digestive and Kidney Diseases in Bethesda, MD, was the first of its kind conducted on humans - and with astonishing results. In the study, 20 participants lived in a lab for four weeks, spending two weeks each on two types of diet: One rich in highly processed foods (like food out of a box or canned prepared food). One rich in whole foods, like whole grains,…