Improvement of insulin resistance after diet with a whole-grain based dietary product: results of a randomized, controlled cross-over study in obese subjects with elevated fasting blood glucose

Abstract

Subjects with obesity and elevated fasting blood glucose are at high risk of developing type 2 diabetes which may be reduced by a dietary intervention leading to an improvement of insulin resistance. We investigated the potential of a whole-grain based dietary product (WG) with reduced starch content derived from double-fermented wheat during a hypo-energetic diet to positively influence body weight, fasting blood glucose, insulin resistance and lipids in comparison to a nutrient-dense meal replacement product (MR) in a randomized two-way cross-over study with two 4-week treatment periods separated by a 2-week wash-out. Subjects replaced at least two daily meals with WG and MR, respectively, targeting for a consumption of 200 g of either product per day. Total daily energy intake was limited to 7120 kJ. Thirty-one subjects (BMI 33·9 (SD 2·7) kg/m 2 , fasting blood glucose 6·3 (SD 0·8) mmol/l) completed the study. In both treatment groups body weight (22·5 (SD 2·0) v. 2 3·2 (SD 1·6) kg for WG v. MR), fasting blood glucose (2 0·4 (SD 0·3) v. 20·5 (SD 0·5) mmol/l), total cholesterol (20·5 (SD 0·5) v. 2 0·6 (SD 0·5) mmol/l), TAG (2 0·3 (SD 0·9) v. 2 0·3 (SD 1·2) mmol/l) and homeostasis model assessment (HOMA) insulin resistance score (20·7 (SD 0·8) v. 21·1 (SD 1·7) mU/ml £ mmol/l) improved (P,0·05) with no significant differences between the treatments. After statistical adjustment for the amount of body weight lost, however, the comparison between both groups revealed that fasting serum insulin (P¼ 0·031) and HOMA insulin resistance score (P¼ 0·049) improved better with WG than with MR. We conclude that WG favourably influences metabolic risk factors for type 2 diabetes independent from the amount of body weight lost during a hypo-energetic diet.Dietary fibre: Insulin resistance: Type 2 diabetes: Whole grain Type 2 diabetes and its long-term complications are a major cause of morbidity and mortality worldwide and the prevalence of the disease continues to rise 1,2 . The increasing incidence of type 2 diabetes is associated with increasing rates of obesity in most countries 3 . Obesity, in turn, is often associated with insulin resistance which is considered as one of the underlying causes of diabetes 4 . Thus, a dietary therapy capable of achieving both weight reduction and improvement of insulin resistance may potentially reduce the incidence of type 2 diabetes in obese subjects prone to develop the disease.Special attention has been focused on carbohydrates in nutrition. Carbohydrates have the greatest influence on postprandial glucose excursions and are the primary stimulus for postprandial insulin release, thus being directly associated with insulin resistance 5 . In Western countries the consumption of cereals constitutes the main source of dietary carbohydrates 6 . Cereals are mostly consumed as highly processed products which have lost a substantial amount of dietary fibre and contain a relatively high concentration of starch because most of the bran and germ is removed in the refining process. In contrast, ...

Impact of Lifestyles of Adolescents and Their Parents on Cardiovascular Risk Factors in Adolescents

“…Different types of fibers have been reported to help control body weight, glucose and lipid metabolism, insulin sensitivity, and the regulation of many inflammatory markers 15) in both adolescents and adults [11][12][13][14] . In the present study, the mean values of fiber intake per day in male and female adolescents (9.1 and 8.5 g/day, respectively) were much lower than the recommended values for male and female Japanese adults (more than 19 and 17 g/day, respectively) 25) ; however, multivariate regression analysis revealed that fiber intake per 1,000 Kcal was the only predictor of low FPG in both genders and was the greatest predictor of low levels of ln (insulin) and ln (HOMA-IR) in females.…”

“…Obesity is associated with a cluster of cardiovascular (CV) risk factors, including abdominal obesity, impaired glucose tolerance, hypertension, and dyslipidemia, which have collectively been termed metabolic syndrome in both children and adults 3,4) . It is well known that the development of CV risk factors, including obesity, is associated with adverse behavioral patterns, such as decreased physical activity [5][6][7][8] , increased sedentary lifestyle, in particular television (TV) watching [8][9][10][11] , and unhealthy dietary habits 5,[11][12][13][14][15][16] . Parental obesity is also strongly associated…”

Effects of total fibre or resistant starch-rich diets within lifestyle intervention in obese prediabetic adults

“…Assuming a 0.64 mmol/L (approximately 10 %) post-diet difference and a 0.8 SD [22], with α = 0.05 and 1 − β = 0.8, a minimum of twenty-five participants were required.…”

Dietary alkylresorcinols and cancer prevention: a systematic review

“…Only a few dietary clinical intervention trials have studied the effect of whole grains intake on health [20, [88][89][90][91]. For example, in a 12-week observational dietary intervention trial (n = 79), Kristensen et al examined the effect of replacing refined wheat with whole grain wheat on body weight and percent body fat [90].…”