Humans have always craved sweet foods. Nutritive sweeteners such as honey and sugar have been enjoyed since the beginning of time, and people were so active in the past that the caloric content of these products was a necessary addition to their diets. With the 20th Century came an era of sedentary lifestyles and convenience foods in the United States and throughout the civilized world, causing increased incidences of obesity and various chronic diseases. These changes in our world created new markets for dieting programs and calorie-free sugar substitutes. The FDA has approved certain nonnutritive sweeteners for use as food additives, such as saccharine, aspartame and sucralose. Each have faced controversy, but these are now the most widely used sweeteners available. Saccharine, the worlds oldest alternative sweetener, was discovered in 1897 by researchers at Johns Hopkins University. Its use was very limited until World War II, when sugar rationing created a need for an inexpensive sugar substitute. Saccharine gained popularity in the 1960's as dieting became more popular, but was removed from the market in 1977 due to a study which linked it to bladder cancer in rats. Since then it has been rigorously tested, and in over 30 human studies it has never been directly linked to cancer in humans. It is not metabolized in our bodies and therefore does not react with our DNA, and has been proven safe for general human consumption. Saccharine, which is found in Sweet & Low, is 500 times sweeter than sucrose, and is used regularly in candies, jams, baked goods, canned fruits, salad dressings, and even in cosmetics and vitamins. Aspartame was discovered by a scientist at G.D. Searle & Company in 1965. Mr. James Schlatter was researching amino acids in hopes to find a treatment for ulcers, when he licked his finger to lift a sheet of paper and noticed the sweet taste. Aspartame, which is made up of protein components, is 200 times sweeter than sucrose, and began being used as a food additive in 1981.