The method has previously been described in detail [5, 6]. In short, the 16 patients, all with BMI>30 kg/m2, free of thyroid cardiac and renal disease – were advised to follow a diet containing initially 1800 kcal for men and 1600 kcal for women. The proportions of carbohydrates, fat and protein were 20%, 50% and 30% respectively. The daily quantity of carbohydrates was 80–90 g. The recommended carbohydrate consumption was limited to vegetables and salad. Instead of ordinary bread crisp/hard bread was recommended, each slice containing 3.5 to 8 g carbohydrates.
Excluded were starch-rich bread, pasta, potatoes, rice and breakfast cereals. The patients were counselled not to eat between meals. It was further recommended that they walk 30 minutes a day and take a daily multivitamin supplement containing extra calcium. There was an introductory meeting lasting most of one day. From day one diabetic medication was reduced by 25–30% to avoid hypoglycaemia. The patients monitored their own blood glucose 4 times a day and were counselled by telephone over the first few weeks for further reductions of medications.
The subjects were followed closely for 6 months with group follow-ups every second week for the first 3 months and once a months for the next 3 months.
The 15 controls were advised on a diet with about the same caloric content at an introductory meeting., Proportions of carbohydrates, fat and protein for this group were 55–60%, 25–30% and 15% respectively. In the normal diabetes diet whole-grain products are recommended. Generous helpings of vegetables and several servings of fruits as snacks between meals are also recommended.
As a number of the controls attended our normal diabetes educational course as introduction to the observation period, the control group on average received about 50% more attention – measured in hours – than the low-carbohydrate group. The controls were then followed in the same way as the low-carbohydrate group.
Seven of the 15 controls switched to a 20% carbohydrate diet immediately after the 6 months follow-up period. For those we have data 32–34 months after the change.
Three more controls sought information and attempted to change diet later at various dates. The 5 remaining controls have not attempted a change of diet despite receiving additional information.
All the patients were known to us and visited the diabetes nurse regularly after the initial period. The same scales and laboratory were used for all measurements. The present report is a review of clinical charts at about 44 months after the start of the study in 2003. Where a figure is missing at 44 months we have taken the mean from the two closest figures. Means are given with standard deviations. T-test for dependent samples is used.