Many of the junk foods on the market today, doughnuts, burgers and pizza, have less nutrients than natural foods, which were dominant a decade or two ago. Many nutritionists claim that pizza and doughnuts give less nourishment than natural foods. A spokesman of a leading junk food company - pizza House - stated recently that an examination of grade school students shows less nutritional deficiency than in their parents’ time. Hence, foods are not as bad as made outto be. Which of the following, if true, would tend to strengthen the view of the spokesman ?