Turku sugar studies. VI. The administration of the trial and the control of the dietary regimen.

125 voluntary subjects, divided into three groups, were originally chosen to participate in a two-year trial in which the dental and general effects of the consumption of sucrose (S 35), fructose (F 38) and xylitol (X 52) were elucidated through an extensive clinico-chemical analysis plan. Additionally 2 edentulous subjects were included in the X-group for survey of the general metabolic effects only. The subjects were given free of charge a versatile assortment of foodstuffs sweetened with either S, F or X. Using special distribution and control systems, the subjects were handled and controlled so that an almost comparable consumption of the products was achieved throughout the trial. The mean individual monthly intake of S, F and X was 2.2, 2.1 and 1.5 kg, respectively. The highest daily amounts of S, F and X per person varied between 200--400 g. The cooperation of the subjects completing the study in the F- and X-groups was 97%, expressed as the intake frequency of the correct sugar. Ten persons discontinued or were otherwise excluded for a diversity of reasons. No health problems were observed, except for transient osmotic diarrhoea in the X-group. These symptoms gradually disappeared and occurred later in the trial in the X-group almost to the same extent as in the S- and F-groups.