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BACKGROUND Oats are a whole grain cereal with potentially favorable effects on the postprandial glycemic response; however, the effects of oat processing on these glycemic benefits are not well understood. OBJECTIVES The study objective was to determine the effects of differently processed oats on the postprandial blood glucose and insulin responses relative to refined grains. METHODS Eleven electronic databases were systematically searched to identify studies published up to and including May 2019. Randomized controlled trials comparing the postprandial blood glucose and insulin responses to oats compared with any refined grain were included, so long as the available carbohydrate content of the test meals was similar. Pooled effect sizes were computed using the difference in incremental area under the curves for blood glucose and insulin following the consumption of oats compared with the refined grain control. RESULTS Ten publications were included, with intact oat kernels studied in 3 comparisons, thick oat flakes (>0.6 mm) in 7 comparisons, and thin/quick/instant oat flakes (≤0.6 mm) in 6 comparisons. Compared with the consumption of the refined grain control, the consumption of intact oat kernels was associated with significant reductions in postprandial blood glucose (-45.5 mmol x min/L; 95% CI: -80.1, -10.9 mmol x min/L; P = 0.010) and insulin (-4.5 nmol x min/L; 95% CI: -7.1, -1.8 nmol x min/L; P = 0.001) responses; the consumption of thick oat flakes was associated with significant reductions in postprandial blood glucose (-30.6 mmol x min/L; 95% CI: -40.4, -20.9 mmol x min/L; P

Avenanthramides (AVNs) are a family of nitrogen-containing phenolic compounds produced in oat; AVN 2c, 2p, and 2f are the three major members. An LC-MS/MS method was developed, with the limit of detection (LOD) and the limit of quantitation (LOQ) being, respectively, 0.29ng/mL and 1.96ng/mL for AVN 2c, 0.24ng/mL and 0.60ng/mL for AVE 2p, and 0.42ng/mL and 2.2ng/mL for AVN 2f. The method was validated in oat-containing hot cereal and snack bar samples. The recovery of AVN 2c, 2p, and 2f from these two oat products was 95-113%, and the relative standard deviations ranged from 5% to 9%. This method was used to evaluate oat products and raw oat samples. The effects of location and variety on AVN composition were investigated. The method presented here provides a novel and rapid tool to quantitate the abundance of AVN 2c, 2p, and 2f in oat-containing products.

Definitions for whole grain (WG) have been published by governments, the food industry, and grain organizations and generally fall into 2 categories: WG and WG food. WG definitions focus on the principal components of the WGs and their proportions, whereas WG-food definitions describe the quantity of WGs present in food. In the United States, widespread agreement exists on the main parts of a definition for a WG, with a definition for a WG food still in its early stages; a standard definition that has been universally accepted does not exist. Furthermore, nutrition policy advises consumers to eat WGs for at least one-half of their total grain intake (2010 and 2015 Dietary Guidelines for Americans), but confusion exists over which foods are considered WGs and how much is needed to achieve health benefits. In December 2014, a workshop sponsored by the subcommittee on collaborative process of the US Government's Interagency Committee on Human Nutrition Research convened in Washington, DC, and recognized WG definitions as a key nutrition and public health-related issue that could benefit from further collaboration. As a follow-up to that meeting, an interdisciplinary roundtable meeting was organized at the Whole Grains Summit on 25 June 2015 in Portland, Oregon, to help resolve the issue. This article summarizes the main opportunities and challenges that were identified during the meeting for defining WGs and WG foods internationally. Definitions of WGs and WG foods that are uniformly adopted by research, food industry, consumer, and public health communities are needed to enable comparison of research results across populations.

Data from the 2001-2010 National Health and Nutrition Examination Survey were analyzed to assess the relationship between oatmeal consumption and nutrient intake, diet quality, and physiological measures in adults 19 years and older (n = 22,823). We hypothesized that oatmeal consumption is associated with a more favorable nutrient intake profile, better diet quality, and healthier physiological end points. Oatmeal consumers (n = 1429) were defined as those who had consumed any amount of cooked oatmeal cereal during a 24-hour recall period. Multiple regression analysis, after transforming variables to normality and using appropriate sample weights to ensure national representation, was used to assess differences between oatmeal consumers and nonconsumers in terms of demographics, and covariate-adjusted analysis of variance was used to assess differences between consumers and nonconsumers in nutrient intakes, diet quality (calculated using the Healthy Eating Index-2010), and physiological measures. Our results show that oatmeal consumers were older than nonconsumers and more likely to be female; they also were less likely to smoke and consumed less alcohol. Consumers had higher intakes of protein, dietary fiber, vitamin A, thiamin, calcium, phosphorus, magnesium, iron, copper, selenium, and potassium and lower intakes of total, monounsaturated, and saturated fats; cholesterol; and vitamin B12. Oatmeal consumers had higher Healthy Eating Index-2010 scores and lower body weights, waist circumferences, and body mass indices. To conclude, our results suggest that consuming oatmeal is consistent with better nutrient intakes and a higher diet quality.

Viscosity generated by oat β-glucan induces gastrointestinal mechanisms that influence appetite. Two oat-based ready-to-eat cereals (RTEC) with similar amounts of β-glucan but differing in their protein and sugar content were compared for their effects on appetite. Forty-seven healthy individuals, ≥18 years old, enrolled in a crossover trial consumed RTEC1 or RTEC2 in random order at least a week apart. Breakfasts contained 250kcals cereal and 105kcals fat-free milk. Subjective ratings of appetite were completed at baseline, and at 30, 60, 120, 180 and 240 minutes after consumption of the breakfast meals. Responses were analyzed as area under the curve (AUC) and per time-point. Significance was set at α=0.05. Fullness (p=0.01) and stomach fullness (p=0.02) were greater with RTEC 1 compared to RTEC 2 at 240 minutes. Stomach fullness (p=0.01) was greater at 30 minutes, and desire to eat (p=0.04) was reduced at 120 minutes with RTEC2 compared to RTEC1. There was no difference in the AUC for hunger, fullness, stomach fullness, desire to eat, or prospective intake. Ready-to-eat cereals containing similar amounts of oat β-glucan differed in the timing of significant differences in fullness or desire to eat, but appetite ratings over a four hour period did not differ.

Background: Foods that enhance satiety can help consumers to resist environmental cues to eat and help adherence to calorie restriction. The objective of this study was to compare the effect of 2 oat-based breakfast cereals on appetite, satiety, and food intake. Methods: Forty-eight healthy individuals, 18 years of age or older, were enrolled in a randomized, crossover trial. Subjects consumed isocaloric servings of either oatmeal or an oat-based ready-to-eat breakfast cereal (RTEC) in random order at least a week apart. Visual analogue scales measuring appetite and satiety were completed before breakfast and throughout the morning. Lunch was served 4 hours after breakfast. The physicochemical properties of oat soluble fiber (β-glucan) were determined. Appetite and satiety responses were analyzed by area under the curve. Food intake and β-glucan properties were analyzed using t tests. Results: Oatmeal increased fullness (p = 0.001) and reduced hunger (p = 0.005), desire to eat (p = 0.001), and prospective intake (p = 0.006) more than the RTEC. Energy intake at lunch was lower after eating oatmeal compared to the RTEC (p = 0.012). Oatmeal had higher viscosity (p = 0.03), β-glucan content, molecular weight (p < 0.001), and radius of gyration (p < 0.001) than the RTEC. Conclusions: Oatmeal suppresses appetite, increases satiety, and reduces energy intake compared to the RTEC. The physicochemical properties of β-glucan and sufficient hydration of oats are important factors affecting satiety and subsequent energy intake.

Background Whole grains are often referred to collectively, despite differences in their composition, physical structure, processing, and potential health benefits. Objective The aim of this study was to compare the postprandial blood glucose response of whole-grain with refined wheat, rice, or rye, while controlling for the food delivery matrix and the processing of the grain (e.g., grinding, germination). Design Eleven electronic databases were systematically searched to identify studies published up to and including November 2017. Randomized controlled trials comparing the effects of whole-grain wheat, rice, or rye with those of each grain's refined counterpart on postprandial blood glucose area under the curve (AUC) were included. Pooled effect sizes were computed by using the difference in the blood glucose AUC after the consumption of the whole compared with the refined grain. Results Twenty publications were included, with 10, 14, and 5 strata (or active-control comparisons) on whole-grain wheat, rice, and rye, respectively. The consumption of ground (wholemeal) wheat, compared with white wheat, was not associated with a significant reduction in blood glucose AUC (-6.7 mmol/L ⋅ min; 95% CI: -25.1, 11.7 mmol/L ⋅ min; P = 0.477). The consumption of wholemeal rye, compared with endosperm rye, was not associated with a significant reduction in blood glucose AUC (-5.5 mmol/L ⋅ min; 95% CI: -24.8, 13.8 mmol/L ⋅ min; P = 0.576). The consumption of intact (whole-grain) rice, compared with white rice, was associated with a significant reduction in blood glucose AUC (-40.5 mmol/L ⋅ min; 95% CI: -59.6, -21.3 mmol/L ⋅ min; P

The objective of the present study was to characterize the consumption of cooked oatmeal in the United States (U.S.) and to determine whether oatmeal consumption is associated with body mass index (BMI). To estimate current intakes of cooked oatmeal in the various age and gender population groups, we used dietary intake data from Day 1 of the U.S. 2009–2010 and 2011–2012 National Health and Nutrition Examination Surveys (NHANES). We also used dietary intake data from Day 1 of the U.S. 2003–2012 NHANES to assess associations between intakes of cooked oatmeal (in g/kg body weight) and NHANES cycle (2003–2004, 2005–2006, 2007–2008, 2009–2010, 2011–2012), age category (3–11 years, 12–18 years, 19–44 years, 45 years+), gender, and BMI classification (underweight, normal weight, overweight, or obese), using a multiple linear regression model. A consumer of oatmeal was defined as any individual who reported the consumption of any amount of oatmeal on Day 1 of the survey. Approximately 6% of the total population consumed oatmeal, with an average intake of 238 g/day of cooked oatmeal among consumers. The greatest prevalence of oatmeal consumption was in infants (14.3%) and older female adults (11.1%). Amongst oatmeal consumers, underweight, normal weight, and overweight individuals consumed significantly more oatmeal than obese individuals. Oatmeal was consumed almost exclusively at breakfast and, among consumers, contributed an average of 54.3% of the energy consumed at breakfast across all age groups examined. The association between oatmeal consumption and BMI is interesting and requires confirmation in future clinical studies.