Twenty five years ago, a remarkable biochemist, Milton Winitz, developed a completely defined chemical diet upon which humans can live indefinitely. He marketed this diet as "Vivonex 100.'' It may still be available. The Winitz diet was made entirely with purified chemicals - amino acids, vitamins, minerals, fats, and carbohydrates. The amounts of chemicals in the diet could not be optimized for each individual person, since the necessary information was unknown. The formula was an average that supported satisfactory health in most people.
One interesting property of this diet is that it requires no digestion and contains no waste. All of the constituents are physiologically absorbed and utilized as provided. Therefore, an individual eating this diet has no solid waste. The colon just rests with nothing to do. This makes the diet useful in treating some digestive disorders. Experiments showed that this rest was not harmful. After many months of disuse, the colon starts working again as soon as it is given something to do.
The original carbohydrate source in Vivonex 100 was solely glucose. In this form, Vivonex 100 was extensively tested on convict volunteers who were biochemically and physiologically monitored during a prolonged period ingesting only this diet.
One remarkable finding was that, after a few weeks on Vivonex 100, the convicts' average blood cholesterol had dropped to about 150 as compared with about 220 previously. The convicts complained, however, about the monotonous taste of the diet, so Winitz decided to provide a variation. He removed 25% of the glucose and replaced it with sucrose. After this, the average of the convicts' blood cholesterols immediately returned to pre-diet levels.
Winitz found that he could control blood cholesterol over a range of a factor of 1.5 - solely by exchanging glucose for sucrose (or, perhaps, glucose for fructose by way of sucrose). See M. Winitz, D. A. Seed-man, & J. Graff, Am. J. Clin. Nutrition 23, p 525-545 (1970)
http://accesstoenergy.com/view/atearchive/s76a2181.htm