Association of Candidate Single-Nucleotide Polymorphism Genotypes With Plasma and Skin Carotenoid Concentrations in Adults Provided a Lycopene-Rich Juice.

BACKGROUND: Carotenoids are fat-soluble phytochemicals with biological roles, including ultraviolet protective functions in skin. Spectroscopic skin carotenoid measurements can also serve as a noninvasive biomarker for carotenoid consumption. Single-nucleotide polymorphisms (SNPs) in metabolic genes are associated with human plasma carotenoid concentrations; however, their relationships with skin carotenoid concentrations are unknown. OBJECTIVES: The objective of this study was to determine the relationship between 13 candidate SNPs with skin and plasma carotenoid concentrations before and after a carotenoid-rich tomato juice intervention. METHODS: In this randomized, controlled trial, participants (n = 80) were provided with lycopene-rich vegetable juice providing low (13.1 mg), medium (23.9 mg), and high (31.0 mg) daily total carotenoid doses for 8 wk. Plasma carotenoid concentrations were measured by high-pressure liquid chromatography, and skin carotenoid score was assessed by reflection spectroscopy (Veggie Meter) at baseline and the end-of-study time point. Thirteen candidate SNPs in 5 genes (BCO1, CD36, SCARB1, SETD7, and ABCA1) were genotyped from blood using PCR-based assays. Mixed models tested the effects of the intervention, study time point, interaction between intervention and study time point, and SNP genotype on skin and plasma carotenoids throughout the study. Baseline carotenoid intake, body mass index, gender, and age are covariates in all models. RESULTS: The genotype of CD36 rs1527479 (P = 0.0490) was significantly associated with skin carotenoid concentrations when baseline and the final week of the intervention were evaluated. Genotypes for BCO1 rs7500996 (P = 0.0067) and CD36 rs1527479 (P = 0.0018) were significant predictors of skin carotenoid concentrations in a combined SNP model. CONCLUSIONS: These novel associations between SNPs and skin carotenoid concentrations expand on the understanding of how genetic variation affects interindividual variation in skin carotenoid phenotypes in humans. This trial was registered at clinicaltrials.gov as NCT03202043.

Daily Dietary Protein Distribution Does Not Influence Changes in Body Composition During Weight Loss in Women of Reproductive Years with Overweight or Obesity: A Randomized Controlled Trial.

BACKGROUND: Preservation of fat-free mass (FFM) during intentional weight loss is challenging yet important to maintain a resting metabolic rate. A balanced protein distribution of 25-30 g per meal improves 24-h muscle protein synthesis, which may promote FFM maintenance and greater reductions in fat mass (FM) during weight loss in women. OBJECTIVES: We aimed to determine whether the daily dietary protein distribution pattern during energy restriction influences changes in body composition in women of reproductive age. We hypothesized that evenly distributing protein across meals compared with the usual intake pattern of consuming most of the protein at the dinner meal would be superior in preserving FFM while reducing FM during weight loss. METHODS: Healthy women (n = 43) aged 20-44 y with a BMI of 28-45 kg/m2 completed a randomized parallel feeding study testing 2 patterns of daily protein intake (even distribution across all meals compared with a skewed distribution with most protein consumed at the evening meal). Participants completed an 8-wk controlled 20% energy restriction (all foods provided), followed by an 8-wk self-choice phase in which participants were asked to maintain a similar diet and dietary pattern when purchasing and consuming their own foods. Body composition was measured at baseline, week 8, and week 16. Data were analyzed using mixed models. Statistical significance was set at P < 0.05. Data are presented as differences in least squares means ± SE. RESULTS: No significant main effects of group or group-by-time interactions were observed. All measures exhibited the main effect of time (P < 0.001). Overall, body weight, FFM, FM, and body fat percentage decreased 5.6 ± 0.4, 1.0 ± 0.2, 4.6 ± 0.4 kg, and 2.3 ± 0.2%, respectively, during this 16-wk study. CONCLUSION: Daily dietary protein distribution at a fixed protein level does not appear to influence changes in body composition during weight loss in women of reproductive age. CLINICAL TRIAL REGISTRY NUMBER AND WEBSITE WHERE IT WAS OBTAINED: NCT03202069 https://classic. CLINICALTRIALS: gov/ct2/show/NCT03202069.

The Role of Dietary Protein in Body Weight Regulation among Active-Duty Military Personnel during Energy Deficit: A Systematic Review.

Active-duty military personnel are subjected to sustained periods of energy deficit during combat and training, leaving them susceptible to detrimental reductions in body weight. The importance of adequate dietary protein intake during periods of intense physical training is well established, where previous research has primarily focused on muscle protein synthesis, muscle recovery, and physical performance. Research on how protein intake may influence body weight regulation in this population is lacking; therefore, the objective of this review was to evaluate the role of dietary protein in body weight regulation among active-duty military during an energy deficit. A literature search based on fixed inclusion and exclusion criteria was performed. English language peer-reviewed journal articles from inception to 3 June 2023 were selected for extraction and quality assessment. Eight studies were identified with outcomes described narratively. The study duration ranged from eight days to six months. Protein was directly provided to participants in all studies except for one. Three studies supplied additional protein via supplementation. The Downs and Black Checklist was used to assess study quality. Five studies were classified as good, two as fair, and one as excellent. All studies reported mean weight loss following energy deficit: the most severe was 4.0 kg. Protein dose during energy deficit varied from 0.5 g/kg/day to 2.4 g/kg/day. Six studies reported mean reductions in fat mass, with the largest being 4.5 kg. Four studies reported mean reductions in fat-free mass, while two studies reported an increase. Results support the recommendation that greater than 0.8 g/kg/day is necessary to mitigate the impact of energy deficit on a decline in lean body mass, while intakes up to 1.6 g/kg/day may be preferred. However, exact recommendations cannot be inferred as the severity and duration of energy deficit varied across studies. Longer and larger investigations are needed to elucidate protein's role during energy deficit in active-duty military.

Biochemical Validation of a Self-Administered Carotenoid Intake Screener to Assess Carotenoid Intake in Nonobese Adults.

Background: Epidemiological studies have demonstrated an association between carotenoid intake and health. However, an accurate measurement of carotenoid intake is challenging. FFQ is the most commonly used dietary assessment method and is typically composed of 100-200 items. However, the greater participant burden that accompanies a more detailed FFQ provides only a marginal gain in accuracy. Therefore, a brief validated carotenoid intake screener is needed. Objectives: To conduct secondary analysis evaluating the validity of a newly developed 44-item carotenoid intake screener from The Juice Study: Sensitivity of Skin Carotenoid Status to Detect Change in Intake (NCT03202043) against corresponding plasma carotenoid concentrations (primary) and skin carotenoids (secondary) in nonobese Midwestern American adults. Methods: Healthy adults (n = 83; 25 men and 58 women) aged 18-65 y (mean age, 32 ± 12 y) with a BMI (in kg/m2) of 18.5-29.9 (mean BMI, 25 ± 3) were recruited between 25 April 2018 and 28 March 2019. Participants completed the carotenoid intake screener weekly during the 8-wk parent study. Plasma carotenoid concentrations were assessed at weeks 0, 4, and 8 using HPLC. Skin carotenoids were assessed weekly using pressure-mediated reflection spectroscopy (RS). Correlation matrices from mixed models were used to determine the correlation between carotenoid intake and plasma and skin carotenoids over time. Results: The total carotenoid intake, as determined by the carotenoid intake screener, correlated with both the plasma total carotenoid concentration (r = 0.52; P < 0.0001) and the RS-assessed skin carotenoid concentration (r = 0.43; P < 0.0001). Correlations between reported intake and plasma concentrations of α-carotene (r = 0.40; P = 0.0002), cryptoxanthin (r = 0.28; P = 0.0113), and lycopene (r = 0.33; P = 0.0022) were also observed. Conclusions: The results of this study demonstrate an acceptable relative validity of the carotenoid intake screener to assess total carotenoid intake in adults classified as those having a healthy body or those with overweight.

Sensitivity of Pressure-Mediated Reflection Spectroscopy to Detect Changes in Skin Carotenoids in Adults Without Obesity in Response to Increased Carotenoid Intake: A Randomized Controlled Trial.

BACKGROUND: The sensitivity of commercially available devices to detect changes in skin carotenoids is not known. OBJECTIVES: We aimed to determine the sensitivity of pressure-mediated reflection spectroscopy (RS) to detect changes in skin carotenoids in response to increasing carotenoid intake. METHODS: Nonobese adults were randomly assigned to a control (water; n = 20; females = 15 (75%); mean age: 31 ± 3 (SE) y; mean BMI: 26 ± 1 kg/m2) or one of 3 carotenoid intake levels: 1) LOW - 13.1 mg; n = 22; females = 18(82%); age: 33 ± 3 y; BMI: 25 ± 1 kg/m2; 2) MED - 23.9 mg; n = 22; females = 17 (77%); age: 30 ± 2 y; BMI: 26 ± 1 kg/m2); or 3) HIGH - 31.0 mg; n = 19; females = 9 (47%); age: 33 ± 3 y; BMI: 24 ± 1 kg/m2. A commercial vegetable juice was provided daily to ensure that the additional carotenoid intake was achieved. Skin carotenoids (RS intensity [RSI]) were measured weekly. Plasma carotenoid concentrations were assessed at wk 0, 4, and 8. Mixed models were used to test the effect of treatment, time, and their interaction. Correlation matrices from mixed models were used to determine the correlation between plasma and skin carotenoids. RESULTS: A correlation was observed between skin and plasma carotenoids (r = 0.65; P < 0.001). Skin carotenoids were greater than baseline starting at week 1 in the HIGH (290 ± 20 vs. 321 ± 24 RSI; P ≤ 0.01), week 2 in the MED (274 ± 18 vs. 290 ± 23 RSI; P ≤ 0.03), and week 3 in the LOW (261 ± 18 vs. 288 ± 15 RSI; P ≤ 0.03). Compared with control, differences in skin carotenoids were observed starting at week 2 in the HIGH ([268 ± 16 vs. 338 ± 26 RSI; P ≤ 0.01] except for week 3 [287 ± 20 vs. 335 ± 26 RSI; P = 0.08]) and week 6 in the MED (303 ± 26 vs. 363 ± 27 RSI; P ≤ 0.03). No differences were observed between the control and LOW. CONCLUSIONS: These findings demonstrate that RS can detect changes in skin carotenoids in adults without obesity when daily carotenoid intake is increased by 13.1 mg for a minimum of 3 wk. However, a minimum difference in intake of 23.9 mg of carotenoids is needed to detect group differences. This trial was registered at ClinicalTrials.gov as NCT03202043.

Incorporating the Dietary Guidelines for Americans Vegetable Recommendations into the Diet Alters Dietary Intake Patterns of Other Foods and Improves Diet Quality in Adults with Overweight and Obesity.

BACKGROUND: Understanding how vegetables are incorporated into the diet, especially in the types and amounts recommended by the Dietary Guidelines for Americans, and how this alters dietary intake patterns is vital for developing targeted behavior change interventions. OBJECTIVE: To determine how a provision of vegetables was incorporated into the diet of adults with overweight and obesity; whether or not the provided vegetables displaced other foods; and what, if any, effect this had on diet quality and body weight and composition. DESIGN: This study investigated secondary outcomes from the Motivating Value of Vegetables Study, a community-based, randomized, parallel, nonblinded controlled trial. Participants were randomly assigned to a provided vegetable intervention or attention control group using a one to one allocation ratio. PARTICIPANTS/SETTING: Men and women with self-reported low vegetable consumption, aged 18 to 65 years, with a body mass index ≥25 were recruited from Grand Forks, ND, between October 2015 and September 2017. Only participants randomized to the provided vegetable intervention group (n = 51; attrition = 8%) were included in this secondary analysis. INTERVENTION: Dietary Guidelines for Americans recommended types and amounts of vegetables were provided weekly for 8 weeks. MAIN OUTCOME MEASURES: How the provided vegetables were incorporated into the diet was measured using daily self-report and 24-hour dietary recalls. Diet quality was assessed via the Healthy Eating Index 2015. Body weight and composition were measured before and after the intervention. STATISTICAL ANALYSES PERFORMED: Data were assessed using generalized linear mixed models where phase (pre, post) was the within-subject factor and subject was the random effect. RESULTS: Participants self-reported using 29% of the provided vegetables as substitutes for other foods. With the increase in vegetable consumption, there were decreases in total grains (mean difference ± standard deviation; -0.97 ± 3.23 oz-equivalents; P = 0.02), protein foods (-1.24 ± 3.86 oz-equivalents; P = 0.01), saturated fats (-6.44 ± 19.63 g; P = 0.02), and added sugars (-2.44 ± 6.78 tsp-equivalents; P = 0.02) consumed. Total Healthy Eating Index 2015 scores increased (+4.48 ± 9.63; P = 0.001) and dietary energy density decreased (-0.44 ± 0.52 kcal/g; P < 0.0001). There was no change in total energy intake or body weight and composition. CONCLUSIONS: Increasing vegetable consumption to meet Dietary Guidelines for Americans recommendations alters dietary intake patterns, improving diet quality and energy density. These findings highlight the importance of characterizing how individuals incorporate Dietary Guidelines for Americans recommendations into their diet.

Postnatal exercise protects offspring from high-fat diet-induced reductions in subcutaneous adipocyte beiging in C57Bl6/J mice.

Maternal low-protein and postnatal high-fat (HF) diets program offspring obesity and type 2 diabetes mellitus (T2DM) risk by epigenetically reducing beige adipocytes (BAs) via increased G9a protein expression (Histone3 Lysine9 dimethyl transferase), an inhibitor of the BA marker fibroblast growth factor 21 (FGF21). Conversely, offspring exercise reduces fat mass and white adipocytes, but the mechanisms are not yet understood. This work investigated whether exercise reduces offspring obesity and T2DM risk caused by a maternal HF diet via regulation of G9a and FGF21 expression that would convert white to BA. Two-month-old female C57Bl/6J mice (F0) were fed a 16% (normal fat; NF) or a 45% HF diet for 3 months prior to breeding, and subsequent gestation and lactation. Male offspring (F1) were fed the same NF and HF diets and further divided into either sedentary (S) or voluntary wheel running (Ex) groups for an additional 3 months yielding eight groups: NF (maternal treatment condition)-NF-S (postweaning treatment conditions), NF-HF-S, NF-NF-Ex, NF-HF-Ex, HF-NF-S, HF-HF-S, HF-NF-Ex, and HF-HF-Ex. Subcutaneous adipose tissue was collected for protein and mRNA analysis of FGF21, peroxisome proliferator-activated receptor-gamma coactivator (PGC-1 alpha, inducer of FGF21), G9a, E4BP4 (G9a coactivator), and protein expression of H3K9 demethylases (KDM4C). Postnatal HF diet decreased FGF21 positive BA numbers regardless of maternal diets and postnatal exercise. Under sedentary conditions, postnatal HF diet increased protein expression of FGF21 transcription inhibitors G9a and E4BP4 compared to NF diet resulting in decreased FGF21 expression. In contrast, postnatal HF diet and exercise decreased G9a and E4BP4 protein expression while decreasing FGF21 expression compared to NF diet. Under exercised condition, postnatal HF diet-induced KDM4C protein expression while no changes in KDM4C protein expression were induced by postnatal HF diet under sedentary conditions. These findings suggest that the postnatal diet exerts a greater impact on offspring adiposity and BA numbers than maternal diets. These data also suggest that offspring exercise induces KDM4C to counter the increase in G9a that was triggered by maternal and postnatal HF diets. Future studies need to determine whether KDM4C induces methylation status of G9a to alter thermogenic function of BA.

Consumption of Dietary Guidelines for Americans Types and Amounts of Vegetables Increases Mean Subjective Happiness Scale Scores: A Randomized Controlled Trial.

BACKGROUND: The health benefits of diets rich in fruits and vegetables (FV) are well established. Recent observational and intervention research suggests that FV consumption may also exert a positive effect on psychological well-being. OBJECTIVE: This study aimed to assess changes in mean Subjective Happiness Scale (SHS) scores in response to consuming 2010-2015 Dietary Guidelines for Americans (DGA) recommended types and amounts of vegetables. It was hypothesized that increased vegetable consumption would increase mean SHS scores. DESIGN: This study investigated a secondary outcome of a randomized, parallel, nonblinded controlled trial with a 1:1 allocation ratio to a provided vegetable intervention or attention control group. PARTICIPANTS/SETTING: Men and women (n = 75) aged 18 to 65 years, body mass index ≥ 25, with low habitual vegetable consumption were recruited from Grand Forks, North Dakota, December 2016 to January 2018, for this community-based study. INTERVENTION: The vegetable intervention consisted of an 8-week feeding phase during which participants were provided with vegetables in DGA-recommended types and amounts. The attention control group was not provided vegetables but completed the same testing schedule as the vegetable intervention group. MAIN OUTCOME MEASURE: Mean SHS scores were assessed before and after the intervention. STATISTICAL ANALYSES: Mean SHS scores were analyzed using a 2-way factorial mixed linear model analysis of variance. RESULTS: A significant interaction between treatment and visit (P = .015) revealed greater mean SHS scores at week 8 than at baseline in the vegetable intervention group (+0.23 ± 0.11) (mean difference ± SE of the difference) but no change in the attention control group (-0.15 ± 0.11). CONCLUSIONS: Greater mean SHS scores were observed after increasing vegetable consumption to meet DGA recommendations, suggesting that adhering to DGA vegetable guidance may help promote psychological well-being.

Dietary Fat Chain Length, Saturation, and PUFA Source Acutely Affect Diet-Induced Thermogenesis but Not Satiety in Adults in a Randomized, Crossover Trial.

Structural differences in dietary fatty acids modify their rate of oxidation and effect on satiety, endpoints that may influence the development of obesity. This study tests the hypothesis that meals containing fat sources with elevated unsaturated fats will result in greater postprandial energy expenditure, fat oxidation, and satiety than meals containing fats with greater saturation. In a randomized, 5-way crossover design, healthy men and women (n = 23; age: 25.7 ± 6.6 years; BMI: 27.7 ± 3.8 kg/m2) consumed liquid meals containing 30 g of fat from heavy cream (HC), olive oil (OO), sunflower oil (SFO), flaxseed oil (FSO), and fish oil (FO). Energy expenditure and diet-induced thermogenesis (DIT) were determined by metabolic rate over a 240 min postprandial period. Serum concentrations of ghrelin, glucose, insulin, and triacylglycerol (TAG) were assessed. DIT induced by SFO was 5% lower than HC and FO (p = 0.04). Energy expenditure and substrate oxidation did not differ between fat sources. Postprandial TAG concentrations were significantly affected by fat source (p = 0.0001). Varying fat sources by the degree of saturation and PUFA type modified DIT but not satiety responses in normal to obese adult men and women.

Consumption of a Variety of Vegetables to Meet Dietary Guidelines for Americans' Recommendations Does Not Induce Sensitization of Vegetable Reinforcement Among Adults with Overweight and Obesity: A Randomized Controlled Trial.

BACKGROUND: Food reinforcement, or the motivation to obtain food, can predict choice and consumption. Vegetable consumption is well below recommended amounts for adults, so understanding how to increase vegetable reinforcement could provide valuable insight into how to increase consumption. OBJECTIVES: We sought to determine whether daily consumption of the Dietary Guidelines for Americans (DGA) recommendations for vegetable intake induces sensitization of vegetable reinforcement in adults with overweight and obesity. METHODS: Healthy adults with a BMI ≥ 25 kg/m2 who consumed ≤1 cup-equivalent of vegetables/day were randomly assigned to a vegetable intervention (VI; n = 55) or an attention control (AC; n = 55) group. The VI consisted of the daily provision of vegetables in the amounts and types recommended by the DGA (∼270 g/day) for 8 weeks. Participants were followed for an additional 8 weeks to assess sustained consumption. Compliance was measured weekly by resonance Raman light-scattering spectroscopy (RRS). Vegetable reinforcement was tested at weeks 0, 8, 12, and 16 using a computer choice paradigm. RESULTS: In the VI group, RRS intensity increased from week 0 to 8 (from 22,990 to 37,220), returning to baseline by week 16 (27,300). No change was observed in the AC group. There was no main effect of treatment (P = 0.974) or time (P = 0.14) and no treatment x time interaction (P = 0.44) on vegetable reinforcement. There was no moderating effect of sex (P = 0.07), age (P = 0.60), BMI (P = 0.46), delay discounting (P = 0.24), 6-n-propylthiouracil taster status (P = 0.15), or dietary disinhibition (P = 0.82) on the change in vegetable reinforcement. CONCLUSIONS: These findings suggest no effects of the provision of a variety of vegetables to meet DGA recommendations for 8 weeks on vegetable reinforcement and highlight the difficulty in increasing vegetable consumption in adults. This trial was registered at clinicaltrials.gov as NCT02585102.

Identification of Barriers to Adherence to a Weight Loss Diet in Women Using the Nominal Group Technique.

BACKGROUND: At any given time, a majority of women are engaged in some type of weight loss diet; however, these efforts are difficult to sustain for long-term weight control. Because women are more likely to develop obesity and suffer a greater severity of obesity-related health and economic consequences, we sought to identify the key factors that make adhering to a weight loss diet difficult for overweight/obese women. METHODS: Ten nominal group technique (NGT) sessions aimed at identifying perceived barriers to adherence to a weight loss diet were conducted as part of a weight loss study for overweight/obese women (n = 33) during the controlled feeding weight loss phase. RESULTS: Individual-level barriers to emerge from the sessions included knowing when to stop eating, being able to control cravings and emotional eating, and sustaining healthier dietary habits. Environmental-level barriers included family/social events that bring people together, especially those centered around food and drink, eating out, cost, and busy schedules. CONCLUSIONS: These findings offer a deeper understanding of barriers women find most salient to adhering to a weight loss diet, providing direction for the clinical application of weight loss programs.

Impact of beef consumption on saturated fat intake in the United States adult population: Insights from modeling the influences of bovine genetics and nutrition.

We sought to determine the impact of breed and finishing ration that reduces the saturated fat (SFA) content of beef on SFA intake (%E) in adults. Using National Health and Nutrition Examination Surveys (2001-2016), we replaced the current fatty acid profile of beef with that from two breeds (Angus, Wagyu) and three finishing rations (pasture, 15% flaxseed supplementation, 35% wet distiller's grain (WDG) supplementation). Dietary replacement levels in the model were 10%, 25%, 50%, 100%. Overall, men consumed more beef fat than women (12.0 g (11.6-12.4 g, 95%CI) and 6.6 g (6.4-6.9 g, 95%CI), respectively). The contribution of beef fat to SFA intake was 2.1%E (2.1-2.2%E, 95%CI) in men and 1.6%E (1.6-1.7%E, 95%CI) in women. SFA intake decreased with each increased replacement level for all beef types. At 100% replacement, SFA intake decreased 0.5% (Angus), 2.8% (Wagyu), 1.9% (pasture), 4.1% (flaxseed), 2.6% (WDG). Our findings demonstrate that breed and finishing ration that reduces the SFA content of beef can decrease population-level SFA intake.

Liking and Acceptability of Whole Grains Increases with a 6-Week Exposure but Preferences for Foods Varying in Taste and Fat Content Are Not Altered: A Randomized Controlled Trial.

BACKGROUND: Since 2005, the Dietary Guidelines for Americans have recommended consuming at least half of total grains as whole grains (WGs) for optimal health benefits; however, consumption of WGs falls far short of recommended amounts. OBJECTIVE: This study aimed to evaluate the effect of mere exposure to WGs on liking, acceptability, and consumption of WG foods and to determine if exposure to WG would influence liking and wanting for other foods varying in fat content and sweet taste. METHODS: Healthy, self-identified low WG consumers (n = 45) were randomly assigned to either a 6-wk WG intervention or a refined grain (RG) control condition during which they received a weekly market basket of grain products to incorporate into daily meals and snacks. Consumption of grain products was measured by weekly logs and weigh-backs. A sensory evaluation protocol was conducted at baseline and week 6 to evaluate changes in perception of grain products. Computer tasks designed to measure liking and wanting for other foods varying in high/low-fat content and sweet/savory taste were also completed at baseline and week 6. RESULTS: Participants in the WG group significantly increased WG consumption. Exposure to WG products resulted in improved ratings of liking, flavor, texture, and willingness to include WG in the regular diet. No significant changes in liking or wanting for foods representing high-fat sweet (HFSW), low-fat sweet (LFSW), high-fat savory (HFSA), or low-fat savory (LFSA) categories were found in the WG group. In contrast, exposure to RG foods resulted in an increased explicit wanting for HFSW and LFSW and a decreased wanting for HFSA foods. CONCLUSIONS: Mere exposure to WG foods represents a feasible and easily applied behavioral strategy for increasing consumption of WGs. Encouraging consumers to focus on enjoyment of the taste may be more effective than emphasizing the health benefits of WG consumption. This trial was registered at clinicaltrials.gov as NCT01403857.

Increasing Chocolate's Sugar Content Enhances Its Psychoactive Effects and Intake.

Chocolate elicits unique brain activity compared to other foods, activating similar brain regions and neurobiological substrates with potentially similar psychoactive effects as substances of abuse. We sought to determine the relationship between chocolate with varying combinations of its main constituents (sugar, cocoa, and fat) and its psychoactive effects. Participants consumed 5 g of a commercially available chocolate with increasing amounts of sugar (90% cocoa, 85% cocoa, 70% cocoa, and milk chocolates). After each chocolate sample, participants completed the Psychoactive Effects Questionnaire (PEQ). The PEQ consists of questions taken from the Morphine-Benzedrine Group (MBG), Morphine (M,) and Excitement (E) subscales of the Addiction Research Center Inventory. After all testing procedures, participants completed the Binge Eating Scale (BES) while left alone and allowed to eat as much as they wanted of each of the different chocolates. We found a measurable psychoactive dose⁻effect relationship with each incremental increase in the chocolate's sugar content. The total number of positive responses and the number of positive responses on the E subscale began increasing after tasting the 90% cocoa chocolate, whereas the number of positive responses on the MBG and M subscales began increasing after tasting the 85% cocoa chocolate sample. We did not find a correlation between BES scores and the total amount of chocolate consumed or self-reported scores on the PEQ. These results suggest that each incremental increase in chocolate's sugar content enhances its psychoactive effects. These results extend our understanding of chocolate's appeal and unique ability to prompt an addictive-like eating response.

Impact of Dietary Protein and Gender on Food Reinforcement.

Recent evidence suggests that increasing dietary protein may alter reward-driven eating behavior. However, the link between protein and food reinforcement is not known. We sought to determine the extent to which increasing dietary protein alters food reinforcement in healthy adults. In a randomized crossover study, 11 women (age = 25 ± 7 years; Body Mass Index (BMI) = 21 ± 2 kg/m²) and 10 men (age = 22 ± 2 years; BMI = 24 ± 2 kg/m²) consumed normal (15%) and high (30%) protein meals. Food reinforcement was assessed using a computer-based choice task (operant responding with concurrent log2(x) reinforcement schedules) 4 h after lunch. We found that food reinforcement was greater in men than women (p < 0.05) and greater for sweet than savory snack foods (p < 0.02). Gender interacted with dietary protein level (p = 0.03) and snack food type (p < 0.0001). Specifically, we found that increasing dietary protein decreased the reinforcing value of savory foods in women. The reinforcing value for sweet foods did not interact with dietary protein or gender. These results demonstrate the differential effects of dietary protein on the reinforcing value for energy-dense, highly palatable snack foods.

The relative reinforcing value of sweet versus savory snack foods after consumption of sugar- or non-nutritive sweetened beverages.

The effects of sugar-sweetened (SSB) and non-nutritive sweetened (NSB) beverages on the regulation of appetite, energy intake and body weight regulation remain controversial. Using a behavioral choice paradigm, we sought to determine the effects of consuming a SSB or NSB on appetite and the reinforcing value of sweet relative to salty/savory snack foods. In a randomized crossover study, 21 healthy weight adults consumed 360 ml of SSB (sucrose; 31 g) or NSB (sucralose; 4 g) with a standardized meal. Hedonic ratings for the sweet and salty/savory snack foods used for the reinforcement task were assessed prior to the start of the study. Satiety and the desire to eat foods with a specific taste profile were assessed before and every 30 min post-meal for 4 h. The relative reinforcing value of the snack foods was assessed using a computer-based choice task (operant responding with concurrent schedules of reinforcement) 4 h post-meal. Hedonic ratings did not differ between the most highly liked sweet and salty/savory snack foods. Beverage type did not influence measures of satiety or the desire to eat foods with a specific taste. However, sweet snacks were more (p < 0.05) reinforcing relative to salty/savory snack foods after consuming a NSB than after a SSB. In conclusion, this is the first study to demonstrate that NSB can increase the motivation to gain access to sweet snacks relative to salty/savory snack foods later in the day.

Postprandial energy metabolism and substrate oxidation in response to the inclusion of a sugar- or non-nutritive sweetened beverage with meals differing in protein content.

BACKGROUND: The macronutrient composition of the diet may play a more important role in maintaining a healthy body weight and preventing obesity than previously thought. The primary goal of this research was to determine the extent to which the simple addition of a small serving of a sugar-sweetened beverage (SSB) to meals with different macronutrient compositions impacts appetite, energy metabolism and substrate oxidation. METHODS: Appetite, energy metabolism and substrate oxidation were measured in 27 healthy weight adults (age = 23 ± 5 y; BMI = 23 ± 2 kg/m2) on two occasions in a room calorimeter after consuming a SSB or a non-nutritive-sweetened beverage (NNSB) with a standard (15%E) or high- (30%E) protein meal. Meal carbohydrate (CHO) content was adjusted to maintain equivalent calories for both study visits. All meals were composed of the same foods and provided 17 g of fat and 500 non-beverage calories. Study visits were separated by at least 1 week and menstruating females were studied during the luteal phase (Days 15-20). The effects of sex, protein level and beverage type and their interactions on satiety, appetite for foods with specific taste profiles, diet-induced thermogenesis (DIT) and rates of substrate oxidation were assessed using a 3-way Repeated Measures Analysis of Variance. RESULTS: Increasing dietary protein decreased hunger and increased satiety. Males were hungrier and less satisfied with the meals than females. Increasing dietary protein also decreased the desire to eat something savory, salty and fatty and the males had a greater appetite for food with these taste profiles. Interestingly, there was no effect of sex, dietary protein or beverage type on the desire to eat something sweet. The inclusion of a SSB markedly suppressed DIT (2.42% ± 5.91%) and fat oxidation (9.87 ± 11.09 g). CONCLUSION: Appetite sensations, food preferences, energy expenditure and substrate oxidation are significantly altered in response to changes in meal macronutrient composition produced by modifications in the protein content of a meal and consumption of a SSB. Most notably, consumption of a SSB during a meal markedly reduces energy efficiency and fat oxidation independent of macronutrient composition. TRIAL REGISTRATIONS: ClinicalTrials.gov: NCT02211599, registered August 05, 2014.

A mobile phone food record app to digitally capture dietary intake for adolescents in a free-living environment: usability study.

BACKGROUND: Mobile technologies are emerging as valuable tools to collect and assess dietary intake. Adolescents readily accept and adopt new technologies; thus, a food record app (FRapp) may be a useful tool to better understand adolescents' dietary intake and eating patterns. OBJECTIVE: We sought to determine the amenability of adolescents, in a free-living environment with minimal parental input, to use the FRapp to record their dietary intake. METHODS: Eighteen community-dwelling adolescents (11-14 years) received detailed instructions to record their dietary intake for 3-7 days using the FRapp. Participants were instructed to capture before and after images of all foods and beverages consumed and to include a fiducial marker in the image. Participants were also asked to provide text descriptors including amount and type of all foods and beverages consumed. RESULTS: Eight of 18 participants were able to follow all instructions: included pre- and post-meal images, a fiducial marker, and a text descriptor and collected diet records on 2 weekdays and 1 weekend day. Dietary intake was recorded on average for 3.2 (SD 1.3 days; 68% weekdays and 32% weekend days) with an average of 2.2 (SD 1.1) eating events per day per participant. A total of 143 eating events were recorded, of which 109 had at least one associated image and 34 were recorded with text only. Of the 109 eating events with images, 66 included all foods, beverages and a fiducial marker and 44 included both a pre- and post-meal image. Text was included with 78 of the captured images. Of the meals recorded, 36, 33, 35, and 39 were breakfasts, lunches, dinners, and snacks, respectively. CONCLUSIONS: These data suggest that mobile devices equipped with an app to record dietary intake will be used by adolescents in a free-living environment; however, a minority of participants followed all directions. User-friendly mobile food record apps may increase participant amenability, increasing our understanding of adolescent dietary intake and eating patterns. To improve data collection, the FRapp should deliver prompts for tasks, such as capturing images before and after each eating event, including the fiducial marker in the image, providing complete and accurate text information, and ensuring all eating events are recorded and should be customizable to individuals and to different situations. TRIAL REGISTRATION: Clinicaltrials.gov NCT01803997. http://clinicaltrials.gov/ct2/show/NCT01803997 (Archived at: http://www.webcitation.org/6WiV1vxoR).

Dietary protein distribution positively influences 24-h muscle protein synthesis in healthy adults.

The RDA for protein describes the quantity that should be consumed daily to meet population needs and to prevent deficiency. Protein consumption in many countries exceeds the RDA; however, intake is often skewed toward the evening meal, whereas breakfast is typically carbohydrate rich and low in protein. We examined the effects of protein distribution on 24-h skeletal muscle protein synthesis in healthy adult men and women (n = 8; age: 36.9 ± 3.1 y; BMI: 25.7 ± 0.8 kg/m2). By using a 7-d crossover feeding design with a 30-d washout period, we measured changes in muscle protein synthesis in response to isoenergetic and isonitrogenous diets with protein at breakfast, lunch, and dinner distributed evenly (EVEN; 31.5 ± 1.3, 29.9 ± 1.6, and 32.7 ± 1.6 g protein, respectively) or skewed (SKEW; 10.7 ± 0.8, 16.0 ± 0.5, and 63.4 ± 3.7 g protein, respectively). Over 24-h periods on days 1 and 7, venous blood samples and vastus lateralis muscle biopsy samples were obtained during primed (2.0 µmol/kg) constant infusion [0.06 µmol/(kg⋅min)] of l-[ring-(13)C6]phenylalanine. The 24-h mixed muscle protein fractional synthesis rate was 25% higher in the EVEN (0.075 ± 0.006%/h) vs. the SKEW (0.056 ± 0.006%/h) protein distribution groups (P = 0.003). This pattern was maintained after 7 d of habituation to each diet (EVEN vs. SKEW: 0.077 ± 0.006 vs. 0.056 ± 0.006%/h; P = 0.001). The consumption of a moderate amount of protein at each meal stimulated 24-h muscle protein synthesis more effectively than skewing protein intake toward the evening meal.

Cancer cachexia and anabolic interventions: a case report.

BACKGROUND: Standard-of-care (SOC) cancer treatments are primarily aimed at reducing size and progression of a tumor. There is a need for successful supplemental anabolic therapies to combat cancer cachexia in addition to these SOC treatment modalities. Anabolic interventions, including testosterone and amino acid supplements, may be beneficial in reducing and/or reversing muscle wasting in these patient populations. METHODS: A 48-year-old Caucasian female with recurrent cervical cancer was scheduled to receive three 21-day cycles of cisplatin and topetecan chemotherapy. She qualified, consented, and enrolled into a blinded interventional pilot study where she received daily whey protein (10 g, three times per day with meals) and a weekly injection of testosterone enanthate (100 mg intramuscular) before and during the SOC chemotherapy treatment period. Body composition, serum inflammatory markers, mixed muscle protein synthesis and breakdown rates, physical function, fatigue, and quality of life were assessed before and after the intervention period. RESULTS: Body composition, as assessed by an increase in body weight and lean body mass and reduction in fat mass; physical function; fatigue; and quality of life each improved across the entire intervention period despite general increases in inflammatory markers and no improvements in muscle protein turnover towards the end of the intervention. CONCLUSIONS: Concomitant treatment of oral amino acids and testosterone may be a viable therapeutic option for fighting cachexia and improving body composition and quality of life during chemotherapeutic treatment of recurrent cervical cancer. These positive outcomes may be attainable over time despite overall poor inflammatory status.