A critical review of low-carbohydrate diets in people with Type 2 diabetes.

AIMS: The efficacy of low-carbohydrate diets (LCD) in people with Type 2 diabetes has divided the nutrition community. This review seeks to re-examine the available data to clarify understanding. METHODS: A comprehensive search of databases was used to identify meta-analyses of LCD in Type 2 diabetes. To improve the quality of the studies analysed, the following inclusion criteria were applied: randomized control trials ≥ 4 weeks in people aged > 18 years with Type 2 diabetes; a carbohydrate intake ≤ 45% of total energy intake per day; and a dietary intake assessment at the end of the study. The resulting studies were subjected to a thematic analysis. RESULTS: Nine meta-analyses were identified containing 153 studies. Twelve studies met our amended inclusion criteria. There were no significant differences in metabolic markers, including glycaemic control, between the two diets, although weight loss with a LCD was greater in one study. Carbohydrate intake at 1 year in very LCD (< 50 g of carbohydrates) ranged from 132 to 162 g. In some studies, the difference between diets was as little as 8 g/day of carbohydrates. CONCLUSION: Total energy intake remains the dietary predictor of body weight. A LCD appears no different from a high-carbohydrate diet in terms of metabolic markers and glycaemic control. Very LCDs may not be sustainable over a medium to longer term as carbohydrate intake in diets within studies often converged toward a more moderate level. The variable quality of studies included in earlier meta-analyses likely explains the previous inconsistent findings between meta-analyses.

A Risk Factor Profile for Chronic Lifestyle Diseases in Three Rural Free State Towns

Background: Chronic diseases of lifestyle account for millions of deaths each year globally. These diseases share similar modifiable risk factors; including hypertension; tobacco smoking; diabetes; obesity; hyperlipidaemia and physical inactivity. In South Africa the burden of noncommunicable disease risk factors is high. To reduce or control as many lifestyle risk factors as possible in a population; the distinct risk-factor profile for that specific community must be identified. Therefore; the aim of this study was to assess the health status in three rural Free State communities and to identify a distinct risk-factor profile for chronic lifestyle diseases in these communities. Methods: This study forms part of the baseline phase of the Assuring Health for All in the Free State project. This is a prospective and longitudinal epidemiological study aimed at determining how living in a rural area can either protect or predispose one to developing chronic lifestyle diseases. The communities of three black and coloured; rural Free State areas; namely Trompsburg; Philippolis and Springfontein; were evaluated. The study population consisted of 499 households; and 658 participants (including children) participated in the study. Only results of adult participants between 25 and 64 years will be reported in this article. The study group consisted of 29.4male and 70.6female participants; with a mean age of 49 years. During interviews with trained researchers; household socio-demographic questionnaires; as well as individual questionnaires evaluating diet; risk factors (history of hypertension and/or diabetes) and habits (tobacco smoking and physical activity levels); were completed. All participants underwent anthropometric evaluation; medical examination and blood sampling to determine fasting blood glucose levels.Results: Multiple risk factors for noncommunicable diseases were identified in this study population; including high blood pressure; tobacco smoking; high body mass index (BMI); diabetes and physical inactivity. The reported risk-factor profile was ranked. Increased waist circumference was ranked highest; high blood pressure second; tobacco smoking third; physical inactivity fourth and diabetes fifth. The cumulative risk-factor profile revealed that 35.6 and 21of this study population had two and three risk factors; respectively. Conclusions: The study demonstrated a high prevalence of risk factors for noncommunicable diseases; e.g. large waist circumference; high BMI; raised blood pressure; tobacco smoking and raised blood glucose levels. Serious consideration should be given to this escalating burden of lifestyle diseases in the study population. The development and implementation of relevant health promotion and intervention programmes that will improve the general health and reduce the risk for noncommunicable diseases in this population are advised

Prevalence of Diabetes Mellitus in Rural Southern Free State

Background: A worldwide increase in the prevalence of diabetes mellitus (DM) has been reported and an even further increase is expected as a result of lifestyle changes. The objectives of this study were to determine the prevalence of DM in the rural southern Free State and to investigate the contribution of risk factors such as age; physical activity; body mass index (BMI); waist-to-hip ratio and waist circumference to the development of impaired fasting glucose (IFG) or DM. Methods: Fasting venous plasma glucose (FVPG) levels were obtained from a total of 552 participants from Springfontein (n = 195); Trompsburg (n = 162) and Philippolis (n = 180). Participants were between 25 and 64 years of age; with 28.1male (mean age 47.3 years) and 71.9female (mean age 46 years). Anthropometric status was determined using standardised techniques. Levels of physical activity were determined using a 24-hour recall of physical activity as well as frequency of performing certain activities. Relative risks (RR) as well as 95confidence intervals (95CI) were used to distinguish significant risk factors for having IFG or DM. Results: In the study population the prevalence of DM was 7.6(5.2in men and 8.6in women) and that of IFG was 6.3(4.5in men and 7.1in women). The majority of nondiabetic (34); IFG (55) and DM (61) participants were between the ages of 51 and 60 years. Age was found to be a statistically significant risk factor for having IFG or DM in participants older than 40 years of age (RR 2.3; 95CI [1.22; 4.34]). Crude measurements (not age- and gender-adjusted) of waist circumference (RR 3.23; 95CI [1.82; 5.74]); BMI (RR 2.32; 95CI [1.43; 3.78]) and waist-to-hip ratio (RR 2.51; 95CI [1.55; 4.07]) were statistically significant risk factors for having IFG or DM. Physical inactivity in men . 40 years was also a statistically significant risk factor (RR 3.23; 95CI [1.15; 9.05]) for having IFG or DM. Conclusions: In this study; 37.5of diabetics were newly discovered. A high waist circumference; BMI and waist-to-hip-ratio were associated with an increased risk for developing IFG or DM; with a high waist circumference being the most significant general risk factor. Physically inactive men (. 40 years) were also at a higher risk of having IFG or DM. Follow-up FVPG and glucose tolerance tests should be performed on participants in the IFG group. A need for intervention regarding the identification and treatment of DM in these rural areas has been identified