A dairy-based, protein-rich breakfast enhances satiety and cognitive concentration before lunch in overweight to obese young females: A randomized controlled crossover study

The purpose of this study was to investigate if consumption of a high-protein, low-carbohydrate breakfast (PRO) leads to a lower subsequent ad libitum energy intake at lunch and the rest of the day compared with ingestion of an isocaloric low-protein, high-carbohydrate breakfast (CHO) or no breakfast (CON). The study was designed as a randomized controlled 3-period crossover study. Thirty young (18-30 yr) females with overweight to obesity (body mass index >25 kg/m2) in random order completed 3 separate experimental days where they consumed either a PRO, CHO, or CON breakfast test meal followed by an ad libitum lunch meal 3 h after breakfast. Participants were allocated to a sequence group by their inclusion number. The PRO and CHO breakfasts were matched in dietary fiber and fat content. Energy intake at lunch was calculated and dietary records were obtained for the rest of the day to calculate the total daily energy intake and macronutrient intake. Ratings of appetite sensations between meals and palatability of the test meals were assessed using visual analog scale sheets in intervals ranging from 10 to 30 min. In addition, blood samples were obtained at multiple time points separated by 10 to 60 min intervals between breakfast and lunch and were analyzed for appetite-regulating gut hormones, insulin, and glucose. Finally, performance in a cognitive concentration test was tested 150 min after breakfast. Compared with CHO and CON, the area under the curves for satiety, fullness, and satisfaction in the 3 h after breakfast were significantly higher after PRO, whereas the areas under the curve for hunger, desire to eat, and prospective eating were significantly lower after PRO. The appetite-regulating gut hormones cholecystokinin, glucagon-like peptide-1, and ghrelin in the hours after breakfast, energy intake during the ad libitum lunch meal, and the total daily energy intake did not differ significantly between PRO, CHO, and CON. However, the cognitive concentration test score was 3.5 percentage points higher for PRO, but not CHO, versus CON. A dairy-based high-protein, low-carbohydrate breakfast increased satiety sensation in the hours after breakfast but did not reduce total daily energy intake compared with an isocaloric low-protein, high-carbohydrate breakfast or omitting breakfast. However, performance in a cognitive concentration test before lunch was enhanced after the high-protein, low-carbohydrate breakfast, but not the low-protein, high-carbohydrate breakfast, compared with omitting breakfast.

Does Pizza Consumption Favor an Improved Disease Activity in Rheumatoid Arthritis?

To our knowledge, no studies so far have investigated the role of pizza and its ingredients in modulating disease activity in rheumatoid arthritis (RA). We assessed this question via a recent cross-sectional study including 365 participants from Italy, the birthplace of pizza. Multiple robust linear and logistic regression models were fitted with the tertile consumption categories of each available pizza-related food item/group (i.e., pizza, refined grains, mozzarella cheese, and olive oil) as independent variables, and each available RA activity measure (i.e., the Disease Activity Score on 28 joints with C-reactive protein (DAS28-CRP), and the Simplified Disease Activity Index (SDAI)) as the dependent variable. Stratified analyses were carried out according to the disease severity or duration. Participants eating half a pizza >1 time/week (vs. ≤2 times/month) reported beneficial effects on disease activity, with the significant reductions of ~70% (overall analysis), and 80% (the more severe stratum), and the significant beta coefficients of -0.70 for the DAS28-CRP, and -3.6 for the SDAI (overall analysis) and of -1.10 and -5.30 (in long-standing and more severe RA, respectively). Among the pizza-related food items/groups, mozzarella cheese and olive oil showed beneficial effects, especially in the more severe stratum. Future cohort studies are needed to confirm this beneficial effect of pizza and related food items/groups on RA disease activity.

Effects of intake of four types of snack with different timings on postprandial glucose levels after dinner

PURPOSE

It has been reported that the consumption of fruit granola (FG), mulberry leaves, and barley cookies as an afternoon snack suppresses the postprandial increase in glucose levels at dinner. However, there have been no reports on the second-meal effect of snacking on popular snacks, such as potato chips (PC), roasted sweet potato (SP), and black beans (BB), or on the interval between snacking and dinner.

METHOD

The present study was an open-label randomized crossover trial of five study groups (PC, SP, BB, FG, and no snack) regarding the second-meal effects with different intervals between snacks and dinner. The subjects consumed prescribed meals for lunch and dinner at 12:00 and 19:00, and a snack fixed at 838 kJ (= 200 kcal) at 15:00 or 17:00.

RESULTS

When the participants snacked at 15:00, the postprandial glucose elevation at dinner was suppressed in the FG and SP groups, and the area under the curve (AUC) was also low. When they snacked at 17:00, the postprandial glucose elevation was suppressed in all the groups. The AUCs for PC, FG, and SP were lower than those for no snacking. On the other hand, carbohydrate intake increased with snacking, but the total AUC of snacks and dinner did not differ in any of the groups. The duration of hyperglycemia decreased with snack intake, as did the glucose amplitude.

CONCLUSION

We believe that the intake of carbohydrates and soluble fiber in snacks is an important factor in the second-meal effect at dinner. These results will contribute to the development of snacking and research into the second-meal effect.

A Randomized, Placebo-Controlled Crossover Study to Evaluate Postprandial Glucometabolic Effects of Mulberry Leaf Extract, Vitamin D, Chromium, and Fiber in People with Type 2 Diabetes

INTRODUCTION

Reducing postprandial (PP) hyperglycemia and PP glucose excursions is important for overall glycemic management. Although most therapeutic lifestyle interventions that reduce caloric intake would affect this, there is no particular nutritional intervention favored.

METHODS

We evaluated the effects of a novel natural food adjuvant combining mulberry leaf extract (MLE) with other bioactive ingredients, in people with type 2 diabetes (T2D) originating from Asia, on improving PP glucometabolic response in a randomized controlled exploratory crossover, two-center study (USA, Singapore). A 2-g blend of 250 mg MLE [containing 12.5 mg of 1-deoxynojirimycin (DNJ)], fiber (1.75 g), vitamin D₃ (0.75 μg), and chromium (75 μg), compared with a similar blend without the MLE, was sprinkled over a 350-kcal breakfast meal (55.4 g carbs) and PP blood glucose (primary exploratory endpoint), insulin, and incretin hormones (GLP-1, GIP) were evaluated in blood samples over 3 h. Changes in incremental areas under the concentration curve (iAUC) and maximum concentrations (C_max) were compared.

RESULTS

Thirty individuals (12 women, mean age 59 years, HbA1c 7.1%, BMI 26.5 kg/m²) were enrolled and the MLE-based blend relative to the blend without MLE significantly reduced glucose iAUC at 1 h (- 20%, p < 0.0001), 2 h (- 17%, p = 0.0001), and 3 h (- 15%, p = 0.0032) and C_max [mean (95% CI) difference - 0.8 (- 1.2, - 0.3) mmol/L, p = 0.0006]. A statistically significant reduction in 1 h insulin iAUC (- 24%, p = 0.0236) was observed, but this reduction was no longer present at either 2 h or 3 h. No difference in GLP-1 was seen, but GIP response (iAUC and C_max) was less with the MLE-based blend.

CONCLUSIONS

The observation of a significant glucose reduction paralleled with a significant lower insulin response supports a reduced gastrointestinal glucose absorption. These results support the use of a 2-g natural blend of MLE, fiber, vitamin D, and chromium in T2D as a convenient dietary adjuvant to improve PP glucometabolic response.

CLINICALTRIALS

gov identifier NCT04877366.

The Effect of Ginger (Zingiber officinale Roscoe) Aqueous Extract on Postprandial Glycemia in Nondiabetic Adults: A Randomized Controlled Trial

Ginger has shown beneficial effects on blood glucose control due to its antioxidant and anti-inflammatory properties. The present study investigated the effect of ginger aqueous extract on postprandial glucose levels in nondiabetic adults and characterized its antioxidant activity. Twenty-four nondiabetic participants were randomly assigned into two groups (NCT05152745), the intervention group (n = 12) and the control group (n = 12). Both groups were administered 200 mL of an oral glucose tolerance test (OGTT), after which participants in the intervention group ingested 100 mL of ginger extract (0.2 g/100 mL). Postprandial blood glucose was measured while fasting and after 30, 60, 90, and 120 min. The total phenolic content, flavonoid content, and antioxidant activity of ginger extract were quantified. In the intervention group, the incremental area under the curve for glucose levels decreased significantly (p < 0.001) and the maximum glucose concentration significantly reduced (p < 0.001). The extract possessed a polyphenolic content of 13.85 mg gallic acid equivalent/L, a flavonoid content of 3.35 mg quercetin equivalent/L, and a high superoxide radical inhibitory capacity (45.73%). This study showed that ginger has a beneficial effect on glucose homeostasis under acute conditions and encourages the use of ginger extract as a promising source of natural antioxidants.

Cow's Milk in Human Nutrition and the Emergence of Plant-Based Milk Alternatives

Cow's milk is considered a complete food, providing high-quality protein and essential micronutrients, including vitamins and minerals. For medical reasons or as a lifestyle choice, consumers are replacing cow's milk with plant-based milk alternatives (PBMA); some perceive them as healthier alternatives to cow's milk due to their low saturated fatty acid content and no cholesterol content. However, the nutritional composition of PBMA is quite variable between different types and even within, which makes a comparison with cow's milk a complex issue. Furthermore, the consumption of PBMA has been associated with the development of some diseases in infants and children. Meanwhile, the consumption of cow's milk in human health is a controversial issue since it has been associated with a favorable effect in some diseases (such as obesity, type 2 diabetes, and Alzheimer's) and a negative effect in others (such as prostate cancer risk and Parkinson's disease); while in some diseases, there is no consensus in the cow's milk consumption effect. The aim of this review is to make a nutritional comparison of cow's milk with PBMA and to clarify the potential health issues related to their consumption.

Effects of milk protein concentrate supplementation on metabolic parameters, adipocytokines and body composition in obese women under weight-loss diet: study protocol for a randomised controlled trial

INTRODUCTION

Obesity impairs metabolic function and increases the risk of cardiovascular disease and type 2 diabetes mellitus. Evidence suggests that high-protein diets help to increase weight loss and protect against weight gain. Milk protein concentrate (MPC) is a dairy product with a high protein content with a ratio of casein and whey protein similar to skim milk. This trial aims to evaluate the effect of MPC supplementation in obese women under a weight-loss diet.

METHODS AND ANALYSIS

We will conduct a 2-month open-label, parallel-group, randomised controlled trial to determine the effect of MPC supplementation on levels of glycaemic and lipid profile, leptin, adiponectin, appetite, waist circumference, body mass index and body composition in 44 premenopausal obese women on a weight-loss diet.

ETHICS AND DISSEMINATION

This protocol, approved by the Medical Ethics Committee of Ahvaz University of Medical Sciences, is in accordance with the Declaration of Helsinki (approval number: IR.AJUMS.REC.1399.795). The trial results will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

Iranian Registry of Clinical Trials (IRCT20201223049804N1).

Insights into the constellating drivers of satiety impacting dietary patterns and lifestyle

Food intake and body weight regulation are of special interest for meeting today's lifestyle essential requirements. Since balanced energy intake and expenditure are crucial for healthy living, high levels of energy intake are associated with obesity. Hence, regulation of energy intake occurs through short- and long-term signals as complex central and peripheral physiological signals control food intake. This work aims to explore and compile the main factors influencing satiating efficiency of foods by updating recent knowledge to point out new perspectives on the potential drivers of satiety interfering with food intake regulation. Human internal factors such as genetics, gender, age, nutritional status, gastrointestinal satiety signals, gut enzymes, gastric emptying rate, gut microbiota, individual behavioral response to foods, sleep and circadian rhythms are likely to be important in determining satiety. Besides, the external factors (environmental and behavioral) impacting satiety efficiency are highlighted. Based on mechanisms related to food consumption and dietary patterns several physical, physiological, and psychological factors affect satiety or satiation. A complex network of endocrine and neuroendocrine mechanisms controls the satiety pathways. In response to food intake and other behavioral cues, gut signals enable endocrine systems to target the brain. Intestinal and gastric signals interact with neural pathways in the central nervous system to halt eating or induce satiety. Moreover, complex food composition and structures result in considerable variation in satiety responses for different food groups. A better understanding of foods and factors impacting the efficiency of satiety could be helpful in making smart food choices and dietary recommendations for a healthy lifestyle based on updated scientific evidence.

Comparative Effects of Co-Ingesting Whey Protein and Glucose Alone and Combined on Blood Glucose, Plasma Insulin and Glucagon Concentrations in Younger and Older Men

The ingestion of dietary protein with, or before, carbohydrate may be a useful strategy to reduce postprandial hyperglycemia, but its effect in older people, who have an increased predisposition for type 2 diabetes, has not been clarified. Blood glucose, plasma insulin and glucagon concentrations were measured for 180 min following a drink containing either glucose (120 kcal), whey-protein (120 kcal), whey-protein plus glucose (240 kcal) or control (~2 kcal) in healthy younger (n = 10, 29 ± 2 years; 26.1 ± 0.4 kg/m2) and older men (n = 10, 78 ± 2 years; 27.3 ± 1.4 kg/m2). Mixed model analysis was used. In both age groups the co-ingestion of protein with glucose (i) markedly reduced the increase in blood glucose concentrations following glucose ingestion alone (p < 0.001) and (ii) had a synergistic effect on the increase in insulin concentrations (p = 0.002). Peak insulin concentrations after protein were unaffected by ageing, whereas insulin levels after glucose were lower in older than younger men (p < 0.05) and peak insulin concentrations were higher after glucose than protein in younger (p < 0.001) but not older men. Glucagon concentrations were unaffected by age. We conclude that the ability of whey-protein to reduce carbohydrate-induced postprandial hyperglycemia is retained in older men and that protein supplementation may be a useful strategy in the prevention and management of type 2 diabetes in older people.

A systematic review of whey protein supplementation effects on human glycemic control: A mechanistic insight

BACKGROUND/AIMS

Some studies showed that dietary factors such as whey protein (WP) are effective on glycemic regulation. Due to the current controversy about WP effects and mechanisms of its action on glycemic control, we conducted this systematic review to shed light on the subject.

METHODS

Web of Science, Medline (Pubmed), and Scopus online databases were searched from 2012 up to February 2022 using the following keywords: "whey protein" and "glycemic control"/"glycemia"/"glucose"/"insulin". The search included original English articles, human clinical trials with WP supplementation and measurement of glucose or insulin as an outcome, studies on healthy individuals/patients with diabetes mellitus (DM)/impaired fasting glucose (IFG).

RESULTS

Title/abstract of 1991 studies were reviewed. After excluding studies due to inappropriate full title and duplication, and exercising inclusion criteria, 58 studies were reviewed in detail. Ample evidence showed that WP decreased postprandial glucose incremental area under the curve (iAUC) and increased iAUCs of insulin and incretin hormones. WP affects glycemic control mainly through stimulating insulin and incretins secretion, slowing gastric emptying, and appetite suppression.

CONCLUSION

Although most of the recent evidence showed beneficial effects of WP supplementation on glycemic response, further long-term clinical trials are required which assess the long-term impact of WP supplementation and its exact mechanisms.

Breakfast Consumption May Improve Fasting Insulin, HOMA-IR, and HbA1c Levels in Predominately Low-Income, Hispanic Children 7-12 Years of Age

Children from low-income households and minority families have high cardiometabolic risk. Although breakfast consumption is known to improve cardiometabolic health in children, limited randomized control trials (RCT) have explored this association in low-income and racial/ethnic U.S. minority families. This study conducted secondary analyses from TX Sprouts, a school-based gardening, cooking, and nutrition education RCT, to examine the intervention effect on breakfast consumption and how changes in breakfast consumption impact cardiometabolic risk in predominately low-income, multi-ethnic children. TX Sprouts consisted of 16 schools (8 intervention; 8 control) in greater Austin, TX. A total of 18 lessons were taught, including topics on breakfast consumption benefits and choosing healthy food options at school. Children completed clinical measures (e.g., anthropometrics, body composition via bioelectrical impedance), and the number of breakfast occasions (BO) per week (at home and school) was captured via validated survey at baseline and post-intervention. Post-study—Baseline changes in breakfast consumption were used to categorize students as: maintainers (BO −1 to 1 day/week), decreasers (BO ≤−2 day/week), and increasers (BO ≥2 day/week). Optional fasting blood draws were performed on a subsample. Generalized weighted linear mixed modeling tested differences between intervention and control, with schools as random clusters. Analysis of covariance and linear regression examined changes in breakfast consumption on cardiometabolic outcomes, controlling for age, sex, race/ethnicity, free and reduced-price school meal participation (FRL), school site, breakfast location, physical activity, baseline cardiometabolic measures, and BMI z-score. This study included 1417 children (mean age 9 years; 53% male; 58% Hispanic, 63% FRL; breakfast consumption patterns: 63% maintainers, 16% decreasers, and 21% increasers). There was no intervention effect on changes in breakfast consumption. Compared to decreasers, increasers had an increase in insulin (−0.3 µIU/mL vs. +4.1 µIU/mL; p = 0.01) and a larger increase in HOMA-IR (+0.4 vs. +1.5; p < 0.01). Every one-day increase in breakfast consumption decreased fasting insulin by 0.44 µIU/mL, HOMA-IR by 0.11, and hemoglobin A1c by 0.01% (p ≤ 0.03). Increased breakfast consumption was linked to improved glucose control, suggesting breakfast can mitigate risk in a high-risk population. To better understand underlying mechanisms linking breakfast consumption to improved metabolic health, RCTs focusing on breakfast quality and timing are warranted.

Comparison of School vs Home Breakfast Consumption with Cardiometabolic and Dietary Parameters in Low-Income, Multiracial/Ethnic Elementary School-Aged Children

BACKGROUND

Breakfast consumption is often associated with improving cardiometabolic parameters and diet quality. However, literature evaluating breakfast consumption with these outcomes between the school and home environments is limited.

OBJECTIVE

This study examined relationships between breakfast consumption locations (school vs home) and cardiometabolic parameters, breakfast dietary intake, and daily dietary intake.

DESIGN

This cross-sectional study used baseline data from TX Sprouts, a 1-year school-based gardening, nutrition, and cooking cluster-randomized trial, implemented in 16 elementary schools in Austin, TX, during 2016 to 2019.

PARTICIPANTS/SETTING

Analyses included 383 low-income, multiracial/ethnic elementary school-aged children (mean age = 9.2 years; 60.6% Hispanic; 70.5% free/reduced lunch; 58.5% home breakfast consumers).

MAIN OUTCOME MEASURES

Cardiometabolic parameters were obtained via fasting blood draws, and dietary intake was assessed using one 24-hour dietary recall conducted on a random, unannounced weekday. Cardiometabolic and dietary parameters (ie, energy intake, macronutrients, and food group servings) for breakfast and for the day were evaluated.

STATISTICAL ANALYSES PERFORMED

Multivariate analysis of covariance was performed to examine cardiometabolic parameters and dietary intake between school and home breakfasts.

RESULTS

School breakfast consumers (SBC) had lower fasting triglyceride levels than home breakfast consumers (HBC) (89.0 mg/dL vs 95.7 mg/dL; P = 0.03) (to convert to mmol/L, multiply by 0.0113). SBC had lower total fat for the day (P = 0.02) and lower total and saturated fat, sodium, and refined grains at breakfast (P ≤ 0.01) than HBC. However, SBC had lower protein at breakfast (P = 0.01) and higher carbohydrates, total sugar, and added sugar for the day and at breakfast (P ≤ 0.03) than HBC.

CONCLUSIONS

SBC compared with HBC had lower fat intake, which may have contributed to the lower triglyceride level observed in SBC, but also had lower protein intake at breakfast and higher added sugar intake for the day and at breakfast. These results suggest dietary intake differed between HBC and SBC; that is, the home and school environments, but more research is needed to evaluate if such differences are due to School Breakfast Program guidelines.

Effect of Reversal of Whey-Protein to Casein Ratio of Cow Milk, on Insulin, Incretin, and Amino Acid Responses in Humans

Scope

Milk‐proteins, besides lactose, stimulate insulin and incretin secretion. Although whey‐proteins (WP) are more efficient than casein (Cas) in hormone secretion, the effects of reversal of the (WP/Cas) ratio in whole‐milk are poorly known.

Methods and Results

Healthy volunteers received two different cow‐milk drinks, at identical lactose (0.36 g × kg⁻¹ BW) and total‐protein (0.18 g × kg¹ BW) loads, but at reversed WP/Cas ratio. One is cow‐whole milk with a ≈20/80 [WP/Cas] ratio, the other an experimental cow‐milk with a ≈70/30 [WP/Cas] ratio ([↑WP↓Cas]‐milk). Both milk‐types induced the same mild hyperglycemic response. Following [↑WP↓Cas]‐milk, the [20′–90′] insulin incremental area (iAUC) (+ ≈44%, p < 0.035), and the [20′–120′] C‐peptide iAUC (+ ≈47%, p < 0.015) are greater than those with cow‐milk. Similarly, following [↑WP↓Cas]‐milk, the GLP‐1 [20′–90′] iAUC (+96%, p < 0.025), and the GIP [30′–60′] iAUC (+140%, p < 0.006), were greater than those with cow‐milk. Plasma total and branched‐chain amino acids are also greater following the [↑WP↓Cas] than cow‐milk.

Conclusions

Reversal of the (WP/Cas) ratio in cow‐milk enhanced the insulin response, an effect possibly mediated by incretins and/or amino acids(s). These data may be useful in designing specific milk formulas with different effects on insulin and incretin response(s).

Age and Sex Interact to Determine the Effects of Commonly Consumed Dairy Products on Postmeal Glycemia, Satiety, and Later Meal Food Intake in Adults

BACKGROUND

Dairy consumption reduces postprandial glycemia and appetite when consumed with carbohydrates.

OBJECTIVES

The objective was to test the effects of frequently consumed dairy products, age, and sex on glycemia, appetite, and food intake.

METHODS

In a randomized, unblinded, crossover design, 30 older [60-70 y; BMI (kg/m2): 18.5-29.9] and 28 young (20-30 y; BMI: 18.5-24.9) adults consumed 500 mL of a calorie-free control (water), skim milk and whole milk, 350 g Greek yogurt, and 60 g cheddar cheese. Food intake at an ad libitum meal was measured 120 min later. Glycemia, appetite, and gastric hormone responses were measured premeal (15-120 min), within-meal (120-140 min), and postmeal (140-170 min). Effects of treatment, age, and sex and their interactions were analyzed using ANOVA followed by Tukey's post hoc test.

RESULTS

All forms of dairy, compared with water, decreased postmeal glycemia, premeal appetite, and meal intake (P < 0.0001). Premeal glucose, insulin, and glucagon-like peptide 1 increased, and ghrelin decreased, but effects of dairy differed with age and sex. Older adults had 10% higher pre- and postmeal glucose (P < 0.01). Premeal appetite suppression per 100 kcal of treatments was more after yogurt than other dairy, but overall appetite suppression was less in older adults than in young adults and in males than in females (P < 0.05). Pizza intake was reduced by 175 kcal after yogurt and cheese and by 82 kcal after milks compared to water (P < 0.001). Mealtime reduction for treatment calories averaged 62% after yogurt and cheese but was less at 33% after milks (P < 0.05). Compensation was less in older (33%) than in young (63%) adults (P < 0.03).

CONCLUSIONS

Dairy products consumed in usual forms before a meal stimulate metabolic responses leading to reduced premeal appetite, later food intake, and postmeal glycemia, but their effects differ in magnitude and with the sex and age of adults.

Whey protein preloading can alleviate stress adaptation disorder and improve hyperglycemia in women with gestational diabetes mellitus

AIMS

To investigate the change of stress hormones, oxidative stress and insulin resistance (IR) in women with gestational diabetes mellitus (GDM) after supplement whey protein, in an attempt to gain insights into the prevention and treatment of GDM.

MATERIALS AND METHODS

60 GDM women were recruited in this study, and 30 women received a preload drink containing 20 g whey protein as group GDM-W, and the other 30 women received control flavoring drink as group GDM, and the trial lasted for 14 days. Plasma epinephrine (E), noradrenaline (NE), and cortisol were detected; we also determined levels of malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH). Homeostasis model assessment of insulin resistance (HOMA-IR) was used to assess IR.

RESULTS

In the GDM-W group, postprandial blood glucose was decreased significantly on 3, 5, 7, and 14 days (all p < .05), plasma 2 h insulin was increased by 7.2, 8.6, and 20.5% on days 5, 7, and 14 (p < .05, .05, .01). HOMA-IR was decreased significantly on day 14 (p < .05). MDA was decreased by 20.7% on day 14 (p < .01), and anti-oxidative enzymes' SOD was decreased by 13.4% on day 14 (p < .05) and GSH was decreased by 16.7 and 29.1% on days 7 and 14 (both p < .05). Stress hormones E and cortisol were decreased by 10.8 and 19.8%, respectively, on day 14 (p < .05). There was no significant difference in NE between the two groups within 14 days.

CONCLUSIONS

Whey protein supplementation may improve hyperglycemia by alleviating stress disorder and oxidative stress injury in GDM women. This trial was registered at chictr.org.cn/as ChiCTR1800020413.

Physicochemical and functional properties of goat milk whey protein and casein obtained during different lactation stages

During lactation, goat milk contains colostrum, transitional milk, mature milk, and end milk. The protein present in goat milk during different lactation periods has different characteristics. This study aimed to characterize the protein profile of goat milk samples obtained at different lactation stages and to identify changes in the physicochemical and functional properties of whey protein and casein from goat milk collected at 1, 3, 15, 100, and 200 d after calving. The results demonstrated that the lactation period had a great influence on the physicochemical and functional properties of goat milk whey protein and casein, especially the protein properties of colostrum on the first day after delivery. The denaturation temperature, hydrophobicity, and turbidity of whey protein were significantly higher on the first day postpartum than at other lactation periods. Correspondingly, the colostrum whey protein also had better functional properties, such as emulsification, oil holding capacity, and foaming properties on the first day postpartum than at other lactation periods. For casein, the turbidity, particle size, water holding capacity, and foaming properties on the first day after delivery were significantly higher than those at other lactation periods, whereas the denaturation temperature, oil holding capacity, and emulsification followed the opposite trend. For both whey protein and casein, the 2 indicators of emulsifying properties, namely, emulsifying activity index and the emulsion stability, also followed an opposite trend relative to lactation stage, whereas the changes in foaming capacity with the lactation period were completely consistent with the change of foaming stability. These findings could provide useful information for the use of goat milk whey protein and casein obtained during different lactation stages in the dairy industry.

Role of Amino Acids in Blood Glucose Changes in Young Adults Consuming Cereal with Milks Varying in Casein and Whey Concentrations and Their Ratio

BACKGROUND

Increasing the total protein content and reducing the casein to whey ratio in milks consumed with breakfast cereal reduce postprandial blood glucose (BG).

OBJECTIVES

We aimed to explore associations between plasma amino acids (AAs), BG, and glucoregulatory hormones.

METHODS

In this repeated-measures design, 12 healthy adults consumed cereal (58 g) and milks (250 mL) with 3.1 wt% or high 9.3 wt% protein concentrations and with casein to whey ratios of either 80:20 or 40:60. Blood was collected at 0, 30, 60, 120, 140, 170, and 200 min for measurement of the primary outcome, BG, and for the exploratory outcomes such as plasma AA, gastric emptying, insulin (INS), and glucoregulatory hormones. Measures were made prior to and after an ad libitum lunch at 120 min. Exploratory correlations were conducted to determine associations between outcomes.

RESULTS

Pre-lunch plasma AA groups [total (TAA), essential (EAA), BCAA, and nonessential (NEAA)] were higher after 9.3 wt% than 3.1 wt% milks by 12.7%, 21.4%, 20.9%, and 7.6%, respectively (P ≤ 0.05), while post-lunch AA groups were higher by 10.9%, 19.8%, 18.8%, and 6.0%, respectively (P ≤ 0.05). Except for NEAA, pre-lunch AAs were higher after 40:60 than 80:20 ratio milks by 4.5%, 8.3%, and 9.3% (P ≤ 0.05). When pooled by all treatments, pre-lunch AA groups associated negatively with BG (r/ρ ≥ -0.45, P ≤ 0.05), but post-lunch only TAA and NEAA correlated (r ≥ -0.37, P < 0.05). Pre-lunch BG was inversely associated with Leu, Ile, Lys, Met, Thr, Cys-Cys, Asn, and Gln (r/ρ ≥ -0.46, P ≤ 0.05), but post-lunch, only with Thr, Ala, and Gly (r ≥ -0.50, P ≤ 0.05). Pre-lunch associations between AA groups and INS were not found.

CONCLUSIONS

Protein concentration and the ratio of casein to whey in milks consumed at breakfast with cereal affect plasma AA concentrations and their associations with decreased BG. The decrease in BG could be explained by INS-independent mechanisms. This trial was registered at www.clinicaltrials.gov as NCT02471092.

Paraprobiotic obtained by ohmic heating added in whey-grape juice drink is effective to control postprandial glycemia in healthy adults

The effect of paraprobiotic Lacticaseibacillus casei 01 inactivated by ohmic heating (8 V/cm, 95 °C/7 min, 60 Hz) whey-grape juice drink at the postprandial glycemia was evaluated. In vitro hypoglycemic activity was assessed by the α-glucosidase and α-amylase inhibition, while in vivo activity was determined using 15 healthy subjects, which consumed bread + probiotic whey drink, bread + paraprobiotic whey drink, and bread alone as a control. The probiotic and paraprobiotic grape-flavored whey drinks showed similar α-glucosidase and α-amylase inhibition (51.2 vs 51.8% and 43.2 vs 44.2%, respectively). The consumption of both paraprobiotic and probiotic whey drinks increased the incremental glucose rate when compared to the control due to the presence of sugar in its composition, without changes in the other parameters evaluated (maximum glucose value, glucose incremental percentage, and peak blood glucose time), showing a reduced glycemic response. In addition, the consumption of the paraprobiotic drink maintained the maximum glucose increase similar to the control, while an increase in this parameter was observed after the consumption of the probiotic drink. Therefore, the paraprobiotic grape-flavored whey drink may be an effective alternative to replace the probiotic product in reducing the postprandial glycemia in healthy individuals.

Effects of cultured dairy and nondairy products added to breakfast cereals on blood glucose control, satiation, satiety, and short-term food intake in young women

Breakfast cereals are often consumed with dairy products or nondairy alternatives; however, the effect of the combination on blood glucose and food intake control is not well investigated. In a randomized, crossover study, 24 healthy women (age: 22.7 ± 2.5 years; body mass index: 22.1 ± 1.5 kg/m²) consumed, to satiation, 1 of 3 treatments: Greek yogurt with granola (150 kcal, 9.2 g protein, 2.6 g fat, 2.0 g dietary fibre, and 21.5 g available carbohydrate/100 g); cultured coconut product with granola (146 kcal, 3.2 g protein, 3.2 g fat, 5.6 g dietary fibre, and 21.9 g available carbohydrate/100 g); or water control. The data were analyzed with repeated-measures ANOVA. The 2 h blood glucose iAUC was 52% lower after the dairy compared with nondairy treatment (P < 0.0001). While there were no differences in food intake between the caloric treatments consumed to satiation, protein intake was 3 times higher and fibre intake was 4 times lower after the dairy compared with nondairy treatment. Both caloric treatments resulted in similar suppression of ad libitum food intake at 2 h (P < 0.003) and subjective appetite over 2 h (P < 0.0001) compared with water. The cumulative food intake over 2 h was lower after water (P < 0.05). The 1.8-fold increase in postprandial insulin after dairy compared with nondairy treatment may explain the reduction in blood glucose without an increase in subsequent energy intake. Novelty Blood glucose in young females is lower after a breakfast with granola in a high-protein cultured dairy than when in a high-fibre nondairy cultured product. Subjective appetite over 2 h and food intake 2 h later was similarly lower after both breakfasts but cumulative intake was higher compared with breakfast skipping.

Postprandial glycemia in healthy subjects: Which probiotic dairy food is more adequate?

The consumption of probiotic-enriched dairy products has been associated with many health benefits, including anti-hyperglycemic activity. The effect on health is dependent on the type of probiotic culture used and the dairy product consumed. This study evaluated the effect of different probiotic-enriched dairy matrices (Minas Frescal cheese, Prato cheese, and whey dairy beverage) containing Lactobacillus casei on in vitro and in vivo anti-hyperglycemic activity. For this purpose, in vitro anti-hyperglycemic activity was determined by the inhibition of α-glucosidase and α-amylase activities, and a human study was performed with healthy individuals (n = 15, consumption of bread as a control; bread + Minas Frescal cheese; bread + Prato cheese; bread + dairy beverage) to assess the effects of different probiotic foods on postprandial glycemia. In vitro data showed that Prato cheese presented the highest lipid (36.9 g/100 g) and protein (26.5 g/100 g) contents as well as the highest α-amylase (60.7%) and α-glucosidase (52.6%) inhibition. The consumption of Prato cheese resulted in a lesser increase in blood glucose level (13 mg/dL) compared with the consumption of bread alone (19 mg/dL), Minas Frescal cheese (20 mg/dL), and whey dairy beverage (30 mg/dL), with glycemic indices similar to that observed for the control. The present results demonstrated a good correlation between in vitro and in vivo data, in which the type of dairy matrix affects the anti-hyperglycemic activity. It is concluded that the consumption of probiotic Prato cheese can contribute to the reduction of postprandial glycemia in healthy individuals.

Postprandial Effects of a Proprietary Milk Protein Hydrolysate Containing Bioactive Peptides in Prediabetic Subjects

Milk proteins have been hypothesized to protect against type 2 diabetes (T2DM) by beneficially modulating glycemic response, predominantly in the postprandial status. This potential is, amongst others, attributed to the high content of whey proteins, which are commonly a product of cheese production. However, native whey has received substantial attention due to its higher leucine content, and its postprandial glycemic effect has not been assessed thus far in prediabetes. In the present study, the impact of a milk protein hydrolysate of native whey origin with alpha-glucosidase inhibiting properties was determined in prediabetics in a randomized, cross-over trial. Subjects received a single dose of placebo or low- or high-dosed milk protein hydrolysate prior to a challenge meal high in carbohydrates. Concentration-time curves of glucose and insulin were assessed. Incremental areas under the curve (iAUC) of glucose as the primary outcome were significantly reduced by low-dosed milk peptides compared to placebo (p = 0.0472), and a minor insulinotropic effect was seen. A longer intervention period with the low-dosed product did not strengthen glucose response but significantly reduced HbA1c values (p = 0.0244). In conclusion, the current milk protein hydrolysate of native whey origin has the potential to modulate postprandial hyperglycemia and hence may contribute in reducing the future risk of developing T2DM.

Increased milk protein content and whey-to-casein ratio in milk served with breakfast cereal reduce postprandial glycemia in healthy adults: An examination of mechanisms of action

This study describes the effects on glycemic response and the underlying mechanisms of action of increasing the protein concentration and decreasing the casein-to-whey ratio in milk when consumed with a high glycemic breakfast cereal. Twelve healthy men and women, aged 18 to 30 yr and with a body mass index of 20 to 24.9 kg/m², consumed (in random order) milk beverages (250 mL) containing either 3.1 or 9.3% protein and casein-to-whey ratios of either 80:20 or 40:60. We measured postprandial appetite, glucose, regulatory hormones, and stomach emptying rate over 200 min, as well as food intake at an ad libitum meal at 120 min. Although pre-meal appetite was suppressed to a greater extent with milk beverages that had high (9.3%) compared with regular (3.1%) protein content, food intake was similar among all 4 treatments. Pre-meal mean blood glucose was lower with beverages that had high rather than regular milk protein content, with the lowest glucose peaks after the high milk protein treatment with the 40:60 casein-to-whey ratio. Pre-meal insulin and C-peptide levels were not affected by milk protein content or casein-to-whey ratio, but pre-meal glucagon-like peptide 1 was higher after the treatment containing high milk protein and the 40:60 casein-to-whey ratio, and pre-meal cholecystokinin was higher after the treatments containing high milk protein content. Plasma paracetamol response was also lower after the treatments containing high compared with regular milk protein content. When consumed with carbohydrate, milk beverages with high protein content and (to a lesser extent) a decreased casein-to-whey ratio lowered postprandial glycemia through insulin-independent mechanisms, primarily associated with delayed stomach emptying.

Role of single serving form of dairy on satiety and postprandial glycaemia in young and older healthy adults

Dairy proteins reduce appetite and improve postprandial glycaemic response in adults. However, there are no reports of dairy in amounts usually consumed on satiety and postprandial glycaemia in either young or older adults. In a randomized crossover design, 30 healthy young adults (age: 23.5 ± 0.5 years; body mass index (BMI): 21.8 ± 0.4 kg/m²) and 30 healthy/overweight older adults (age: 65.2 ± 0.5 years; BMI: 24.7 ± 0.6 kg/m²) consumed 1 serving (according to manufacturers' labels) of skim milk (0.1% milk fat (MF)), whole milk (3.25% MF), plain Greek yogurt (2% MF), cheddar cheese (31% MF), and water (energy-free control) after a 12-h fast. Subjective appetite was measured every 15-30 min over 3 h. Blood glucose and insulin were measured at baseline and every 15-30 min over 2 h. All dairy treatments reduced post-treatment subjective appetite area under the curve (AUC) over 3 h by 8%-17% more than water. Greek yogurt reduced appetite 3-h AUC more than skim and whole milk by 9% and 7%, respectively (p < 0.0001). Post-treatment blood glucose 2-h AUC was 42% lower in young compared with older adults (p = 0.003). It was also 52%-78% lower after cheese compared with milks and yogurt (p < 0.0001). Post-treatment insulin AUC after cheese was only 10%-15% of that after milks and Greek yogurt (p < 0.0001). We conclude that single servings of dairy differ in effect on postprandial satiety and glycaemia and merit consideration in management of metabolic syndrome.