In type 2 diabetes, randomisation to advice to follow a low-carbohydrate diet transiently improves glycaemic control compared with advice to follow a low-fat diet producing a similar weight loss

摘要

Aims/hypothesis The study aimed to compare the effects of a 2?year intervention with a low-fat diet (LFD) or a low-carbohydrate diet (LCD), based on four group meetings to achieve compliance. Methods This was a prospective randomised parallel trial involving 61 adults with type 2 diabetes consecutively recruited in primary care and randomised by drawing ballots. Patients that did not speak Swedish could not be recruited. The primary outcomes in this non-blinded study were weight and HbA1c. Patients on the LFD aimed for 55–60 energy per cent (E%) and those on LCD for 20?E% from carbohydrate. Results The mean BMI and HbA1c of the participants were 32.7?±?5.4?kg/m2 and 57.0?±?9.2?mmol/mol, respectively. No patients were lost to follow-up. Weight loss did not differ between groups and was maximal at 6?months: LFD ?3.99?±?4.1?kg (n?=?31); LCD ?4.31?±?3.6?kg (n?=?30); p?p?=?0.002 and p?=?0.020 within groups, respectively). HbA1c fell in the LCD group only (LCD at 6?months ?4.8?±?8.3?mmol/mol, p?=?0.004, at 12?months ?2.2?±?7.7?mmol/mol, p?=?0.12; LFD at 6?months ?0.9?±?8.8?mmol/mol, p?=?0.56). At 6?months, HDL-cholesterol had increased with the LCD (from 1.13?±?0.33?mmol/l to 1.25?±?0.47?mmol/l, p?=?0.018) while LDL-cholesterol did not differ between groups. Insulin doses were reduced in the LCD group (0?months, LCD 42?±?65 E, LFD 39?±?51 E; 6?months, LCD 30?±?47 E, LFD 38?±?48 E; p?=?0.046 for between-group change). Conclusions/interpretation Weight changes did not differ between the diet groups, while insulin doses were reduced significantly more with the LCD at 6?months, when compliance was good. Thus, aiming for 20% of energy intake from carbohydrates is safe with respect to cardiovascular risk compared with the traditional LFD and this approach could constitute a treatment alternative. Trial registration: ClinicalTrials.gov NCT01005498 Funding: University Hospital of Link?ping Research Funds, Link?ping University, the County Council of ?sterg?tland, and the Diabetes Research Centre of Link?ping University