Concern over the safety and nutritional quality of many processed foods has been heightened by reports on food additives, preservatives, and carcinogens. A 1976 USDA survey indicated that many consumers were changing their diets because of existing health problems or concerns about preventing future health problems. Individuals who had altered their diets were concerned about preservatives, artificial sweeteners, food colorings, and flavor enhancers in food and beverages. During the mid- to late-1960's natural foods were considered a passing fad. Today, natural foods have become a part of our national eating habits. That people are demanding more natural food is evidenced by the dramatic rise in the number of health/natural food stores in the last 10 years, increasing from 1,200 in 1968 to over 6,600 in 1978. And it is reported that new stores are still opening at the rate of 400 per year. Total store sales increased from $170 million in 1970 to $1.6 billion in 1978 and are projected to reach $3 billion by 1990. Though the health/natural foods market is growing, sales of $1.6 billion in 1978 represented only 0.9 percent of total U.S. grocery store food sales that year ($179.6 billion). And the 6,600 health/natural food stores accounted for only 4 percent of grocery stores. In an effort to share in the flourishing natural foods business, many conventional grocery stores are stocking health/natural food products or have added a separate section devoted entirely to health/natural foods.