Higher Expression of miR-15b-5p with Inclusion of Fresh, Lean Beef as Part of a Healthy Dietary Pattern Is Inversely Associated with Markers of Cardiometabolic Disease Risk.

BACKGROUND: Considerable controversy exists surrounding the consumption of red meat and its impacts on cardiometabolic health and if it may further impact risk factors at the molecular level. OBJECTIVE: The purpose of this study was to examine the acute effects of dietary patterns, varying in red meat quantity, on the expression of circulating microRNAs (miRNAs), which are emerging biomarkers of metabolic dysfunction and chronic disease severity. METHODS: Secondary analyses were performed on plasma samples collected within a randomized, crossover design study in 16 women with overweight (mean ± standard deviation, age = 33 ± 9.89 y; body mass index = 27.9 ± 1.66 kg/m2). Participants were provided with eucaloric, isonitrogenous diets (15% of daily intake as protein) containing either 2 servings of fresh, lean beef/day (BEEF) or 0 servings of fresh, lean beef/day (PLANT) for 7 d/pattern. Fasting blood samples were collected at the end of each dietary pattern for the assessment of 12 circulating metabolic miRNA expression levels (determined a priori by quantitative reverse transcriptase-polymerase chain reaction), plasma glucose, insulin, interleukin-6, tumor necrosis factor-α, C-reactive protein (CRP), adiponectin, glucagon-like peptide-1, and branched-chain amino acids. RESULTS: Of the 12 miRNAs, miR-15b-5p expression was higher following BEEF versus PLANT (P = 0.024). Increased miR-15b-5p expression correlated with decreased fasting CRP (r = -0.494; P = 0.086) and insulin concentrations (r = -0.670; P = 0.017). miR-15b-5p was inversely correlated with insulin resistance (r = -0.642; P = 0.024) and ß cell function (r = -0.646; P = 0.023) and positively correlated with markers of insulin sensitivity (r = 0.520; P = 0.083). However, the correlations were only observed following BEEF, not PLANT. CONCLUSIONS: These data indicate that the short-term intake of fresh, lean beef as part of a healthy dietary pattern impacts potential biomarkers of cardiometabolic health that are associated with cardiometabolic risk factors in women with overweight. This study was registered at clinicaltrials.gov as NCT02614729.

Protein Source Influences Acute Appetite and Satiety but Not Subsequent Food Intake in Healthy Adults.

BACKGROUND: Although current recommendations encourage plant-based dietary patterns, data is limited as to whether the equivalent substitution of animal-based protein-rich foods with plant-based versions impacts ingestive behavior. OBJECTIVES: To compare higher-protein preloads, varying in protein source, on appetite, satiety, and subsequent energy intake. METHODS: Thirty-two adults (age: 25 ± 1 y; body mass index (BMI) measured in kg/m2: 24.2 ± 0.5 kg/m2) randomly consumed 250 kcal, protein-preload beverages (24 g protein), varying in protein source [whey, soy, and pea protein isolates (WHEY, SOY, and PEA) or micellar casein (CAS)] each morning for 3 acclimation days/preload. On day 4, participants completed a 4-h clinical testing day in which the respective preload was consumed, followed by blood sampling and questionnaires every 30 min for appetite and satiety. In addition, an ad libitum lunch was provided 4-h postpreload. On day 5, participants consumed the respective preload at home, followed by an ad libitum breakfast 30 min afterward. For normally-distributed data, repeated-measures analysis of variance (ANOVA) or Friedman nonparametric test were utilized to compare the main effects of protein source on study outcomes. Post hoc pairwise comparisons using least-significant differences (LSD) were then performed. RESULTS: CAS (-3330 ± 690 mm∗240 min) and PEA (-2840 ± 930mm∗240 min) reduced 4-h appetite compared with SOY (-1440 ± 936 mm∗240 min; both, P < 0.05). WHEY was not different (-2290 ± 930 mm∗240 min). CAS (3520 ± 84 pg/mL∗240 min) and PEA (3860 ± 864 pg/mL∗240 min) increased 4-h peptide YY concentrations compared with SOY (2200 ± 869 pg/mL∗240 min; both, P < 0.05). WHEY was not different (3870 ± 932 pg/mL∗240 min). No differences in ad libitum energy intake were observed. CONCLUSIONS: CAS and PEA, but not WHEY, elicited greater acute changes in appetite and satiety compared with SOY in healthy adults, supporting that not all protein sources are equivalent. This trial is registered at clinicaltrials.gov (NCT03154606).

Important Concepts in Protein Nutrition, Aging, and Skeletal Muscle: Honoring Dr Douglas Paddon-Jones (1969-2021) by Highlighting His Research Contributions.

This review is a tribute to honor Dr Douglas Paddon-Jones by highlighting his career research contributions. Dr Paddon-Jones was a leader in recognizing the importance of muscle health and the interactions of physical activity and dietary protein for optimizing the health span. Aging is characterized by loss of muscle mass and strength associated with reduced rates of muscle protein synthesis (MPS) and the ability to repair and replace muscle proteins. Research from the team at the University of Texas Medical Branch in Galveston discovered that the age-related decline in MPS could be overcome by increasing the quantity or quality of dietary protein at each meal. Dr Paddon-Jones was instrumental in proposing and testing a "protein threshold" of ∼30 g protein/meal to optimize MPS in older adults. Dr Paddon-Jones demonstrated that physical inactivity greatly accelerates the loss of muscle mass and function in older adults. His work in physical activity led him to propose the "Catabolic Crisis Model" of muscle size and function losses, suggesting that age-related muscle loss is not a linear process, but the result of acute periods of disuse associated with injuries, illnesses, and bed rest. This model creates the opportunity to provide targeted interventions via protein supplementation and/or increased dietary protein through consuming high-quality animal-source foods. He illustrated that nutritional support, particularly enhanced protein quantity, quality, and meal distribution, can help preserve muscle health during periods of inactivity and promote health across the life course.

Consuming a Protein and Fiber-Based Supplement Preload Promotes Weight Loss and Alters Metabolic Markers in Overweight Adults in a 12-Week, Randomized, Double-Blind, Placebo-Controlled Trial.

BACKGROUND: Higher protein and fiber diets promote weight management and metabolic health. OBJECTIVES: This study aimed to determine if greater weight loss and positive changes in metabolic outcomes could be achieved with twice-daily consumption of a high-protein and fiber-based multi-ingredient nutritional shake (HPF) compared with an isocaloric low-protein, lower fiber-based placebo (LPF). METHODS: Study procedures were conducted by an independent research organization under clinicaltrials.gov registration NCT03057873. Healthy overweight and obese adults [n = 206; BMI (kg/m2): 27-35; 70% female] were randomly assigned to HPF or LPF. All participants were prescribed an energy-restricted diet (500 kcal/d less than energy needs) and consumed a HPF (17 g protein, 6 g fiber) or LPF (1 g protein, 3 g fiber) shake 30 min before breakfast and lunch for 12 wk. Primary outcomes included body weight and total body fat percentage. Blood samples were collected at days (D) 0, 28, 56, and 84 for secondary analyses related to metabolic markers of health. RESULTS: Although weight loss occurred in both groups, HPF had greater weight loss at D84 compared with LPF (-3.3 kg vs. -1.8 kg, P < 0.05). Percentage body fat decreased in both groups (HPF: -1.33%, LPF: -1.09%; P < 0.001) with no differences between groups. Serum total cholesterol, LDL cholesterol, and oxidized LDL decreased between -5.1% to -8.3%, whereas adiponectin increased over time in both groups; these changes occurred to a greater extent in HPF compared with LPF (all P < 0.05). CONCLUSIONS: A multi-ingredient HPF nutritional supplement shake consumed as a preload before breakfast and lunch positively influenced weight management and metabolic outcomes in overweight adults compared with an LPF placebo. These findings suggest that specific nutrient factors (i.e., potentially including protein, fiber, and bioactive content) other than calorie reduction alone influence the success of a weight-loss regimen. This trial was registered at www.clinicaltrials.gov as NCT03057873.

An Afternoon Hummus Snack Affects Diet Quality, Appetite, and Glycemic Control in Healthy Adults.

BACKGROUND: Snacking continues to be a major component in the dietary patterns of most Americans despite conflicting evidence surrounding snacking healthfulness. Low-sugar, highly nutritive snacks, such as hummus, can lead to improvements in diet quality, appetite, and glycemic control. OBJECTIVES: The purpose of the study was to examine the effects of afternoon snacking on diet quality, appetite, and glycemic control in healthy adults. METHODS: Thirty-nine adults (age: 26 ± 1 y; BMI: 24.4 ± 0.5 kg/m2) randomly completed the following afternoon snack patterns for 6 d/pattern: hummus and pretzels [HUMMUS; 240 kcal; 6 g protein, 31 g carbohydrate (2 g sugar), 11 g fat]; granola bars [BARS; 240 kcal; 4 g protein, 38 g carbohydrate (16 g sugar), 9 g fat]; or no snacking (NO SNACK). On day 7 of each pattern, a standardized breakfast and lunch were provided. The respective snack was provided to participants 3 h after lunch, and appetite, satiety, and mood questionnaires were completed throughout the afternoon. At 3 h postsnack, a standardized dinner was consumed, and an evening snack cooler was provided to be consumed, ad libitum at home, throughout the evening. Lastly, 24 h continuous glucose monitoring was performed. RESULTS: HUMMUS reduced subsequent snacking on desserts by ∼20% compared with NO SNACK (P = 0.001) and BARS (P < 0.001). HUMMUS led to greater dietary compensation compared with BARS (122 ± 31% compared with 72 ± 32%, respectively; P < 0.05). HUMMUS reduced indices of appetite (i.e., hunger, desire to eat, and prospective food consumption) by ∼70% compared with NO SNACK (all P < 0.05), whereas BARS did not. Additionally, satiety was ∼30% greater following HUMMUS and BARS compared with NO SNACK (both P < 0.005) with no differences between snacks. Lastly, HUMMUS reduced afternoon blood glucose concentrations by ∼5% compared with BARS (P < 0.05). CONCLUSIONS: Acute consumption of a low-sugar, afternoon hummus snack improved diet quality and selected indices of appetite, satiety, and glycemic control in healthy adults. Long-term trials assessing the effects of hummus snacking on health outcomes are warranted.

Breakfast Consumption Is Positively Associated with Usual Nutrient Intakes among Food Pantry Clients Living in Rural Communities.

BACKGROUND: Breakfast consumption has declined over the past 40 y and is inversely associated with obesity-related diet and health outcomes. The breakfast pattern of food pantry clients and its association with diet is unknown. OBJECTIVE: The objective is to investigate the association of breakfast consumption with diet quality and usual nutrient intakes among food pantry clients (n = 472) living in rural communities. METHODS: This was an observational study using cross-sectional analyses. English-speaking participants ≥18 y (or ≥19 y in Nebraska) were recruited from 24 food pantries in rural high-poverty counties in Indiana, Michigan, Missouri, Nebraska, Ohio, and South Dakota. Participants were surveyed at the pantry regarding characteristics and diet using 24-h recall. A second recall was self-completed or completed via assisted phone call within 2 wk of the pantry visit. Participants were classified as breakfast skippers when neither recall reported breakfast ≥230 kcal consumed between 04:00 and 10:00; breakfast consumers were all other participants. The Healthy Eating Index-2010 was modeled with breakfast pattern using multiple linear regression. Mean usual intake of 16 nutrients was estimated using the National Cancer Institute Method and compared across breakfast pattern groups. Usual nutrient intake was compared with the Estimated Average Requirement (EAR) or Adequate Intake (AI) to estimate the proportion of population not meeting the EAR or exceeding the AI. RESULTS: A total of 56% of participants consumed breakfast. Compared with breakfast skippers, breakfast consumers had 10-59% significantly higher usual mean intakes of all nutrients (P ≤ 0.05), and had 12-21% lower prevalence of at-risk nutrient intakes except for vitamin D, vitamin E, and magnesium. CONCLUSIONS: Adult food pantry clients living in rural communities experienced hardships in meeting dietary recommendations. Breakfast consumption was positively associated with usual nutrient intakes in this population. This trial was registered at clinicaltrials.gov as NCT03566095.

Consuming Lower-Protein Nutrition Bars with Added Leucine Elicits Postprandial Changes in Appetite Sensations in Healthy Women.

BACKGROUND: Higher-protein meals (>25 g protein/meal) have been associated with enhanced satiety but the role of amino acids is unclear. Leucine has been proposed to stimulate satiety in rodents but has not been assessed in humans. OBJECTIVE: We assessed the acute effects of lower-protein nutrition bars, enhanced with a leucine peptide (LP), on postprandial appetite sensations in combination with plasma leucine and peptide YY (PYY) in healthy women. METHODS: Utilizing a double-blind randomized crossover design, 40 healthy women [28 ± 7.5 y; body mass index (BMI, in kg/m2): 23.5 ± 2.4] consumed the following isocaloric (180 kcal) pre-loads on 3 separate visits: control bar [9 g protein with 0 g added LP (0-g LP)] or treatment bars [11 g protein with 2 g added LP (2-g LP) or 13 g protein with 3 g added LP (3-g LP)]. Pre- and postprandial hunger, desire to eat, prospective food consumption (PFC), fullness, and plasma leucine were assessed every 30 min for 240 min. Plasma PYY was assessed hourly for 240 min (n = 24). RESULTS: Main effects of time (P < 0.0001) and treatment (P < 0.03) were detected for postprandial hunger, desire to eat, PFC, and fullness. Post hoc analyses revealed that the 2-g and 3-g LP bars elicited greater increases in fullness and greater decreases in PFC compared with 0-g LP (all, P < 0.05) with no differences between the 2-g and 3-g LP bars. The 2-g bar elicited greater decreases in hunger and desire to eat compared with the 0-g LP bar (both, P ≤ 0.01), whereas 3-g LP did not. Appetite incremental areas under the curves (iAUCs) and PYY outcomes were not different between bars. A treatment × time interaction was detected for plasma leucine with increases occurring in a leucine-dose-dependent manner (P < 0.0001). CONCLUSION: Despite the dose-dependent increases in plasma leucine following the consumption of lower-protein bars enhanced with LP, only the 2-g LP bar elicited consistent postprandial changes in select appetite sensations compared with the 0-g LP bar. This study was registered on clinicaltrials.gov as NCT02091570.

Increased Protein Consumption during the Day from an Energy-Restricted Diet Augments Satiety but Does Not Reduce Daily Fat or Carbohydrate Intake on a Free-Living Test Day in Overweight Women.

Background: Higher-protein (HP) energy-restriction diets improve weight management to a greater extent than normal-protein (NP) versions. Potential mechanisms of action with regard to assessment of eating behaviors across the day have not been widely examined during energy restriction.Objectives: The objectives of this study were to test whether the consumption of an HP energy-restriction diet reduces carbohydrate and fat intakes through improvements in daily appetite, satiety, and food cravings compared with NP versions and to test whether protein type within the NP diets alters protein-related satiety.Methods: Seventeen overweight women [mean ± SEM age: 36 ± 1 y; body mass index (kg/m2): 28.4 ± 0.1] completed a randomized, controlled-feeding crossover study. Participants were provided with the following ∼1250-kcal/d energy-restricted (-750-kcal/d deficit) diets, each for 6 d: HP [124 g protein/d; 60% from beef and 40% from plant sources (HP-BEEF)] or NP (48 g protein/d) that was protein-type matched (NP-BEEF) or unmatched [100% from plant-based sources (NP-PLANT)]. On day 6 of each diet period, participants completed a 12-h testing day containing repetitive appetite, satiety, and food-craving questionnaires. On day 7, the participants were asked to consume their protein requirement within each respective diet but were provided with a surplus of carbohydrate- and fat-rich foods to consume, ad libitum, at each eating occasion across the day. All outcomes reported were primary study outcomes.Results: The HP-BEEF diet reduced daily hunger by 16%, desire to eat by 15%, prospective food consumption by 14%, and fast-food cravings by 15% but increased daily fullness by 25% compared with the NP-BEEF and NP-PLANT diets (all P < 0.05). However, consuming more protein throughout the day did not reduce the energy consumed ad libitum from the fat- and carbohydrate-rich foods (HP-BEEF: 2000 ± 180 kcal/d; NP-BEEF: 2120 ± 190 kcal/d; NP-PLANT: 2070 ± 180 kcal/d). None of the outcomes differed between the NP-BEEF and NP-PLANT treatments.Conclusions: Although appetite control, satiety, and food cravings improved after an HP energy-restriction diet, increased protein consumption did not reduce carbohydrate and fat intakes throughout the free-living test day in overweight healthy women exposed to highly palatable foods. This trial was registered at clinicaltrials.gov as NCT02614729.

Magnitude of daily energy deficit predicts frequency but not severity of menstrual disturbances associated with exercise and caloric restriction.

We assessed the impact of energy deficiency on menstrual function using controlled feeding and supervised exercise over four menstrual cycles (1 baseline and 3 intervention cycles) in untrained, eumenorrheic women aged 18-30 yr. Subjects were randomized to either an exercising control (EXCON) or one of three exercising energy deficit (ED) groups, i.e., mild (ED1; -8 ± 2%), moderate (ED2; -22 ± 3%), or severe (ED3; -42 ± 3%). Menstrual cycle length and changes in urinary concentrations of estrone-1-glucuronide, pregnanediol glucuronide, and midcycle luteinizing hormone were assessed. Thirty-four subjects completed the study. Weight loss occurred in ED1 (-3.8 ± 0.2 kg), ED2 (-2.8 ± 0.6 kg), and ED3 (-2.6 ± 1.1 kg) but was minimal in EXCON (-0.9 ± 0.7 kg). The overall sum of disturbances (luteal phase defects, anovulation, and oligomenorrhea) was greater in ED2 compared with EXCON and greater in ED3 compared with EXCON AND ED1. The average percent energy deficit was the main predictor of the frequency of menstrual disturbances (f = 10.1, ß = -0.48, r(2) = 0.23, P = 0.003) even when weight loss was included in the model. The estimates of the magnitude of energy deficiency associated with menstrual disturbances ranged from -22 (ED2) to -42% (ED3), reflecting an energy deficit of -470 to -810 kcal/day, respectively. This is the first study to demonstrate a dose-response relationship between the magnitude of energy deficiency and the frequency of exercise-related menstrual disturbances; however, the severity of menstrual disturbances was not dependent on the magnitude of energy deficiency.

Consuming Beef vs. Soy Protein Has Little Effect on Appetite, Satiety, and Food Intake in Healthy Adults.

BACKGROUND: Although protein-rich plant foods have recently been touted as an equivalent to animal products, limited data exist regarding the effects of animal vs. plant proteins on appetite, satiety, and subsequent food intake. OBJECTIVE: The objective was to determine whether a high-protein beef lunch alters the appetitive, hormonal, and neural signals controlling food intake regulation vs. a macronutrient and fiber-matched (MF) or serving size-matched (SS) soy lunch in healthy adults. METHODS: A randomized, double-blind, crossover design study was completed in 21 adults (aged 23 ± 1 y; body mass index: 23.8 ± 0.6 kg/m²; mean ± SEM) to compare 400-kcal MF and SS lunches varying in protein quality. The MF lunches contained 24-g beef protein or 24-g soy protein, whereas the SS lunches contained 1 serving of beef (24-g protein/1-g fiber) or soy (14-g protein/5-g fiber). Pre- and postlunch appetite questionnaires and blood sampling were completed over an 8-h period until dinner was voluntarily requested. In addition, pre- and postlunch functional MRI brain scans were completed to assess neural activation in response to food stimuli. RESULTS: On average, dinner was requested at ∼250 ± 20 min postlunch with no differences between beef vs. soy within the MF and SS conditions. Furthermore, no differences in hunger, fullness, peptide YY, or glucagon-like peptide-1 responses were observed after the beef vs. soy lunches within the MF and SS conditions. The SS beef meal led to reductions in anterior cingulate activation (-22 ± 6%) vs. soy (+7 ± 9%; P < 0.01) and greater reductions in insular activation (-30 ± 6%) vs. SS soy (-7 ± 10%; P < 0.01). The participants consumed ∼945 ± 78 kcal after the MF meals and 910 ± 74 kcal after the SS meals with no differences between beef vs. soy. CONCLUSIONS: When comparing 2 high-quality protein sources, such as beef and soy, the type of protein consumed within a mixed meal elicited very little effect on appetite, satiety, and food intake in healthy adults.

A high-protein breakfast induces greater insulin and glucose-dependent insulinotropic peptide responses to a subsequent lunch meal in individuals with type 2 diabetes.

BACKGROUND: The previous meal modulates the postprandial glycemic responses to a subsequent meal; this is termed the second-meal phenomenon. OBJECTIVE: This study examined the effects of high-protein vs. high-carbohydrate breakfast meals on the metabolic and incretin responses after the breakfast and lunch meals. METHODS: Twelve type 2 diabetic men and women [age: 21-55 y; body mass index (BMI): 30-40 kg/m(2)] completed two 7-d breakfast conditions consisting of 500-kcal breakfast meals as protein (35% protein/45% carbohydrate) or carbohydrate (15% protein/65% carbohydrate). On day 7, subjects completed an 8-h testing day. After an overnight fast, the subjects consumed their respective breakfast followed by a standard 500-kcal high-carbohydrate lunch meal 4 h later. Blood samples were taken throughout the day for assessment of 4-h postbreakfast and 4-h postlunch total area under the curve (AUC) for glucose, insulin, C-peptide, glucagon, glucose-dependent insulinotropic peptide (GIP), and glucagon-like peptide 1 (GLP-1). RESULTS: Postbreakfast glucose and GIP AUCs were lower after the protein (17%) vs. after the carbohydrate (23%) condition (P < 0.05), whereas postbreakfast insulin, C-peptide, glucagon, and GLP-1 AUCs were not different between conditions. A protein-rich breakfast may reduce the consequences of hyperglycemia in this population. Postlunch insulin, C-peptide, and GIP AUCs were greater after the protein condition vs. after the carbohydrate condition (second-meal phenomenon; all, P < 0.05), but postlunch AUCs were not different between conditions. The overall glucose, glucagon, and GLP-1 responses (e.g., 8 h) were greater after the protein condition vs. after the carbohydrate condition (all, P < 0.05). CONCLUSIONS: In type 2 diabetic individuals, compared with a high-carbohydrate breakfast, the consumption of a high-protein breakfast meal attenuates the postprandial glucose response and does not magnify the response to the second meal. Insulin, C-peptide, and GIP concentrations demonstrate the second-meal phenomenon and most likely aid in keeping the glucose concentrations controlled in response to the subsequent meal. The trial was registered at www.clinicaltrials.gov/ct2/show/NCT02180646 as NCT02180646.

Consuming High-Protein Soy Snacks Affects Appetite Control, Satiety, and Diet Quality in Young People and Influences Select Aspects of Mood and Cognition.

BACKGROUND: Data concerning the effects of afternoon snacking on ingestive behavior, mood, and cognition are limited. OBJECTIVE: The purpose of this study was to compare 1088 kJ of high-protein (HP) or high-fat (HF) afternoon snacks vs. no snacking on appetite, food intake, mood, and cognition in adolescents. METHODS: Thirty-one healthy adolescents (age: 17 ± 1 y) consumed the following afternoon snacks (in randomized order) for 3 d: HP snack (26 g of protein/6 g of fat per 27 g of carbohydrates), HF snack (4 g of protein/12 g of fat per 32 g of carbohydrates), and no snack (NoS). On day 4 of each treatment, the participants completed an 8-h testing day containing pre- and postsnack appetite questionnaires, food cue-stimulated functional MRI brain scans, mood, cognitive function, and eating initiation. Ad libitum dinner and evening snacks were provided and assessed. RESULTS: HP, but not HF, delayed eating initiation vs. NoS (P < 0.05). Both snacks reduced appetite vs. NoS (P < 0.001) with HP eliciting greater reductions than HF (P < 0.05). Only HF led to reductions in corticolimbic activation in brain regions controlling food motivation/reward vs. NoS (P < 0.01). Although no treatment differences in daily energy intake were detected, HP led to greater protein consumption than NoS (P < 0.05) and greater protein and lower fat consumption than HF (both, P < 0.05). HP led to fewer HF/high-sugar evening snacks than NoS (P < 0.01) and HF (P = 0.09). Although no treatment effects were detected for mood and cognition, HP tended to reduce confusion-bewilderment (P = 0.07) and increase cognitive flexibility (P = 0.09), whereas NoS reduced tension-anxiety (P < 0.05) and vigor-activity (P < 0.05). CONCLUSION: Afternoon snacking, particularly on HP soy foods, improves appetite, satiety, and diet quality in adolescents, while beneficially influencing aspects of mood and cognition. This trial was registered at clinicaltrials.gov as NCT01781286.

Western diet-induced hepatic steatosis and alterations in the liver transcriptome in adult Brown-Norway rats.

BACKGROUND: The purpose of this study was to investigate the effects of sub-chronic high fat, high sucrose diet (also termed 'Westernized diet' or WD) feeding on the liver transcriptome during early nonalcoholic fatty liver disease (NAFLD) development. METHODS: Brown Norway male rats (9 months of age) were randomly assigned to receive ad libitum access to a control (CTL; 14 % kcal fat, 1.2 % sucrose by weight) diet or WD (42 % kcal from fat, 34 % sucrose by weight) for 6 weeks. RESULTS: Six weeks of WD feeding caused hepatic steatosis development as evidenced by the 2.25-fold increase in liver triacylglycerol content, but did not induce advanced liver disease (i.e., no overt inflammation or fibrosis) in adult Brown Norway rats. RNA deep sequencing (RNA-seq) revealed that 94 transcripts were altered in liver by WD feeding (46 up-, 48 down-regulated, FDR < 0.05). Specifically, the top differentially regulated gene network by WD feeding was 'Lipid metabolism, small molecular biochemistry, vitamin and mineral metabolism' (Ingenuity Pathway Analysis (IPA) score 61). The top-regulated canonical signaling pathway in WD-fed rats was the 'Superpathway of cholesterol biosynthesis' (10/29 genes regulated, p = 1.68E-17), which coincides with a tendency for serum cholesterol levels to increase in WD-fed rats (p = 0.09). Remarkably, liver stearoyl-CoA desaturase (Scd) mRNA expression was by far the most highly-induced transcript in WD-fed rats (approximately 30-fold, FDR = 0.01) which supports previous literature underscoring this gene as a crucial target during NAFLD development. CONCLUSIONS: In summary, sub-chronic WD feeding appears to increase hepatic steatosis development over a 6-week period but only induces select inflammation-related liver transcripts, mostly acute phase response genes. These findings continue to outline the early stages of NAFLD development prior to overt liver inflammation and advanced liver disease.

A randomized, controlled, crossover trial to assess the acute appetitive and metabolic effects of sausage and egg-based convenience breakfast meals in overweight premenopausal women.

BACKGROUND: Dietary protein at breakfast has been shown to enhance satiety and reduce subsequent energy intake more so than carbohydrate or fat. However, relatively few studies have assessed substitution of protein for carbohydrate on indicators of appetite and glucose homeostasis simultaneously. METHODS: The acute appetitive and metabolic effects of commercially-prepared sausage and egg-based breakfast meals at two different protein levels (30 g and 39 g/serving), vs. a low-protein pancake breakfast (3 g protein) and no breakfast (water), were examined in premenopausal women (N = 35; age 32.5 ± 1.6 yr; BMI 24.8 ± 0.5 kg/m(2)). Test products provided ~280 kcal/serving and similar fat (12-14 g) and fiber contents (0-1 g). Visual Analog Scale ratings for appetite (hunger, fullness, prospective consumption, desire to eat) and repeated blood sampling for plasma glucose and insulin concentrations were assessed throughout each test day. Energy intake was recorded at an ad libitum lunch meal at 240 min. RESULTS: Results showed increased satiety ratings for both the 30 and 39 g protein meals vs. the low-protein and no breakfast conditions (p < 0.001 for all). Postprandial glucose and insulin excursions were lower following the 30 g and 39 g protein conditions vs. the low-protein condition, with smaller responses following the 39 g vs. 30 g protein condition (p < 0.05 for all). Energy intake at lunch was significantly less (p < 0.001) following the 39 g protein meal (692 kcal) vs. the low-protein and no breakfast conditions (789 and 810 kcal, respectively). Total energy intake from the test condition + lunch was higher (p < 0.01) for the 30 and 39 g meals (982 and 983 kcal, respectively) vs. no breakfast (810 kcal), and less than the low protein breakfast (1064 kcal; p < 0.01 vs. 39 g condition only). CONCLUSIONS: Results suggest that convenience meals providing 30 or 39 g protein/serving produce greater appetite control, lower postprandial glycemia and insulinemia, and reduced subsequent intake at lunch relative to a low-protein control, or no breakfast. TRIAL REGISTRATION: NCT01713114.

A randomized crossover, pilot study examining the effects of a normal protein vs. high protein breakfast on food cravings and reward signals in overweight/obese "breakfast skipping", late-adolescent girls.

BACKGROUND: This pilot study examined whether the addition of a normal protein (NP) vs. high protein (HP) breakfast leads to alterations in food cravings and plasma homovanillic acid (HVA), which is an index of central dopamine production, in overweight/obese 'breakfast skipping' late-adolescent young women. METHODS: A randomized crossover design was incorporated in which 20 girls (age 19 ± 1 y; BMI 28.6 ± 0.7 kg/m2) consumed 350 kcal NP (13 g protein) breakfast meals, 350 kcal HP (35 g protein) breakfast meals, or continued breakfast skipping (BS) for 6 consecutive days/pattern. On day 7 of each pattern, a 4 h testing day was completed including the consumption of breakfast (or no breakfast) followed by food craving questionnaires and blood sampling for HVA concentrations throughout the morning. RESULTS: Both breakfast meals reduced post-meal cravings for sweet and savory foods and increased HVA concentrations vs. BS (all, p < 0.05). Between breakfast meals, the HP breakfast tended to elicit greater reductions in post-meal savory cravings vs. NP (p = 0.08) and tended to elicit sustained increases in HVA concentrations prior to lunch vs. NP (p = 0.09). Lastly, HVA concentrations were positively correlated with the protein content at breakfast (r: 0.340; p < 0.03). CONCLUSIONS: Collectively, these findings suggest that the addition of breakfast reduces post-meal food cravings and increases homovanillic acid concentrations in overweight/obese young people with higher protein versions eliciting greater responses.

Effects of high-protein vs. high- fat snacks on appetite control, satiety, and eating initiation in healthy women.

BACKGROUND: The purpose of this study was to determine whether a high-protein afternoon yogurt snack improves appetite control, satiety, and reduces subsequent food intake compared to other commonly-consumed, energy dense, high-fat snacks. FINDINGS: Twenty, healthy women (age: 27 ± 2 y; BMI: 23.4 ± 0.7 kg/m2) completed the randomized crossover design study which included 3, 8-h testing days comparing the following 160 kcal afternoon snacks: high-protein yogurt (14 g protein/25 g CHO/0 g fat); high-fat crackers (0 g protein/19 g CHO/9 g fat); and high-fat chocolate (2 g protein/19 g CHO/9 g fat). Participants were acclimated to each snack for 3 consecutive days. On day 4, the participants consumed a standardized breakfast and lunch; the respective snack was consumed 3-h post-lunch. Perceived hunger and fullness were assessed throughout the afternoon until dinner was voluntarily requested. An ad libitum dinner was then provided. The consumption of the yogurt snack led to greater reductions in afternoon hunger vs. chocolate (p < 0.01). No differences in afternoon fullness were detected. The yogurt snack also delayed eating initiation by approximately 30 min compared to the chocolate snack (p < 0.01) and approximately 20 min vs. crackers (p = 0.07). The yogurt snack led to approximately 100 fewer kcals consumed at dinner vs. the crackers (p = 0.08) and chocolate (p < 0.05). No other differences were detected. CONCLUSION: These data suggest that, when compared to high-fat snacks, eating less energy dense, high-protein snacks like yogurt improves appetite control, satiety, and reduces subsequent food intake in healthy women.

Increased dietary protein as a dietary strategy to prevent and/or treat obesity.

Obesity in America continues to be a major public health concern. Emerging scientific evidence suggests that a diet rich in high-quality protein is a beneficial dietary strategy to prevent and/or treat obesity. This paper provides a brief synopsis of the latest research regarding the effects of higher protein diets to improve body weight management and energy intake regulation. Specific focus on the effects of increased dietary protein on appetite control, satiety, and food cravings are also explored.

Indices of Sleep Health Are Associated With Timing and Duration of Eating in Young Adults.

BACKGROUND: Limited data exist examining whether timing and/or duration of eating behaviors throughout the day affect sleep health. OBJECTIVE: The aim of this study was to identify the relationship between eating behaviors and sleep in young adults without chronic diseases or conditions. DESIGN: This was a cross-sectional study using 7 days of baseline data from a randomized crossover trial. PARTICIPANTS/SETTING: Participants included 52 young adults. The study took place in West Lafayette, Indiana, between April 2017 and May 2018. MAIN OUTCOME MEASURES: Timing and duration of eating were assessed via 3 nonconsecutive, 24-hour dietary recalls. Bedtime, wake time, total sleep time, sleep latency, sleep efficiency, and wake after sleep onset were measured over 7 days via wrist actigraphy and sleep diaries. STATISTICAL ANALYSES PERFORMED: Two-way analyses of variance were applied to assess group differences based on timing of consumption (early vs late eating) and duration of eating (long: >13 hours, short: <11 hours, or standard: 11-13 hours) with post-hoc pairwise comparisons. RESULTS: Main effects of timing of consumption, but not duration of eating, were detected for wake time, bedtime, and sleep efficiency (all, P < .05). Specifically, participants with later eating patterns that included breakfast skipping had later wake times and later bedtimes than those with earlier eating patterns. In addition, those who had later eating patterns that included breakfast skipping and nighttime eating experienced lower sleep efficiency (mean [SE], 77.0% [2.3%]) vs those who consumed breakfast and no nighttime eating (mean [SE], 84.6% [1.4%]; P < .001) and those who skipped breakfast but had no nighttime eating (mean [SE], 84.2% [2.5]; P < .05). Those who consumed breakfast but also had nighttime eating had a mean (SE) sleep efficiency of 82.4% (1.4%) (P = .09). CONCLUSIONS: The timing of eating was associated with sleep-wake onset and sleep efficiency. This study provides the preliminary characterization of eating behaviors relative to sleep-wake cycles and highlights the need for experimental studies to understand whether manipulating the timing of eating occasions to better align with sleep-wake cycles could improve sleep health.

Examining the Direct and Indirect Effects of Postprandial Amino Acid Responses on Markers of Satiety following the Acute Consumption of Lean Beef-Rich Meals in Healthy Women with Overweight.

The consumption of protein-rich foods stimulates satiety more than other macronutrient-rich foods; however, the underlying mechanisms-of-action are not well-characterized. The objective of this study was to identify the direct and indirect effects of postprandial amino acid (AA) responses on satiety. Seventeen women (mean ± SEM, age: 33 ± 1 year; BMI: 27.8 ± 0.1 kg/m2) consumed a eucaloric, plant-based diet containing two servings of lean beef/day (i.e., 7.5 oz (207 g)) for 7 days. During day 6, the participants completed a 12 h controlled-feeding, clinical testing day including repeated satiety questionnaires and blood sampling to assess pre- and postprandial plasma AAs, PYY, and GLP-1. Regression and mediation analyses were completed to assess AA predictors and hormonal mediators. Total plasma AAs explained 41.1% of the variance in perceived daily fullness (p < 0.001), 61.0% in PYY (p < 0.001), and 66.1% in GLP-1 (p < 0.001) concentrations, respectively. Several individual AAs significantly predicted fluctuations in daily fullness, PYY, and GLP-1. In completing mediation analyses, the effect of plasma leucine on daily fullness was fully mediated by circulating PYY concentrations (indirect effect = B: 0.09 [Boot 95% CI: 0.032, 0.17]) as no leucine-fullness direct effect was observed. No other mediators were identified. Although a number of circulating AAs predict satiety, leucine was found to do so through changes in PYY concentrations in middle-aged women.

Decreased luteinizing hormone pulse frequency is associated with elevated 24-hour ghrelin after calorie restriction and exercise in premenopausal women.

Elevated ghrelin has been shown to be associated with reduced luteinizing hormone (LH) pulsatility in Rhesus monkeys, rats, men, and recently women. We previously reported that 24-h ghrelin concentrations are elevated in women following a 3-mo exercise and diet program leading to weight loss. We investigated whether the elevations in ghrelin following an ~3-mo exercise and diet program leading to weight loss are associated with a decrease in LH pulsatility. The nonexercising control group (Control, n = 5) consumed a controlled diet that matched energy needs, whereas energy intake in the exercise group (Energy Deficit, n = 16) was reduced from baseline energy requirements and supervised exercise training occurred five times per a week. Significant decreases in body weight (-3.0 ± 0.6 kg), body fat (-2.9 ± 0.4 kg) and 24-h LH pulse frequency (-0.18 ± 0.08 pulses/h), and a significant increase in 24-h mean ghrelin were observed in only the Energy Deficit group. The pre-post change in LH pulse frequency was negatively correlated with the change in mean 24-h ghrelin (R = -0.485, P = 0.030) and the change in peak ghrelin at lunch (R = -0.518, P = 0.019). Interestingly, pre-post change in night LH pulse frequency was negatively correlated with the change in mean day ghrelin (R = -0.704, P = 0.001). Elevated total ghrelin concentrations are associated with the suppression of LH pulsatility in premenopausal women and may play a role in the suppression of reproductive function following weight loss.