Functional food science and behaviour and psychological functions

The impact of ingesting various foods on psychological and behavioural functions is a topic of both interest and concern to the general public. In this article, the scientific literature concerning demonstrated cause-and-effect relationships is reviewed, beginning with methodological considerations specific to the quantification of particular behaviours and psychological events. The essential function of food is to satisfy hunger and the need for essential nutrients. The contributions of macronutrients to appetite and satiety are described, as well as their impact on metabolism and energy balance. Functional properties of macronutrient substitutes (high intensity sweeteners, fat replacers) and flavour enhancers are examined in relation to their contribution to hunger, satiety, and energy balance. The effects of foods and individual nutrients on the performance of diverse psychomotor tasks are studied with consideration given to the various validated quantitative tools used to assess behaviour. The effects of food components on activation, sedation, and affective states such as dysphoria are also reviewed, with special attention given to brain function and neuroactive substances such as serotonin and the endorphins. The case of hyperactivity in children is given special emphasis with reference to the potential influence of sugar and food additives. Safety issues related to food constituents and additives are discussed. Finally, a set of criteria is proposed for the evaluation and elaboration of studies in the behavioural and psychological fields, along with suggestions for future researc

Augmenting muscle diacylglycerol and triacylglycerol content by blocking fatty acid oxidation does not impede insulin sensitivity

A low fat oxidative capacity has been linked to muscle diacylglycerol (DAG) accumulation and insulin resistance. Alternatively, a low fat oxidation rate may stimulate glucose oxidation, thereby enhancing glucose disposal. Here, we investigated whether an ethyl-2-[6-(4-chlorophenoxy)hexyl]-oxirane-2-carboxylate (etomoxir)-induced inhibition of fat oxidation leads to muscle fat storage and insulin resistance. An intervention in healthy male subjects was combined with studies in human primary myotubes. Furthermore, muscle DAG and triacylglycerol (TAG), mitochondrial function, and insulin signaling were examined in etomoxir-treated C57bl6 mice. In humans, etomoxir administration increased glucose oxidation at the expense of fat oxidation. This effect was accompanied by an increased abundance of GLUT4 at the sarcolemma and a lowering of plasma glucose levels, indicative of improved glucose homeostasis. In mice, etomoxir injections resulted in accumulation of muscle TAG and DAG, yet improved insulin-stimulated GLUT4 translocation. Also in human myotubes, insulin signaling was improved by etomoxir, in the presence of increased intramyocellular lipid accumulation. These insulin-sensitizing effects in mice and human myotubes were accompanied by increased phosphorylation of AMP-activated protein kinase (AMPK). Our results show that a reduction in fat oxidation leading to accumulation of muscle DAG does not necessarily lead to insulin resistance, as the reduction in fat oxidation may activate AMPK

The acute effects of a lunch containing capsaicin on energy and substrate utilisation, hormones, and satiety

BACKGROUND: Addition of capsaicin to the diet has been shown to increase satiety and thermogenesis. The effects of capsaicin on ghrelin, peptide YY (PYY) and glucagon-like peptide 1 (GLP-1), in relation to changes in hunger and satiety are unknown. AIM: To test the acute effects of a lunch containing capsaicin on gut derived hormones (GLP-1, ghrelin, and PYY), energy expenditure (EE), substrate oxidation and satiety at lunch in the postprandial state. METHODS: Thirty subjects (age: 31 +/- 14 years, BMI: 23.8 +/- 2.8 kg/m(2)) were studied twice in a crossover design. After 30 min resting on a bed, resting metabolic rate was measured by a ventilated hood system. Subsequently lunch (35% of daily energy intake) was served. The two lunch conditions were: (1) lunch without capsaicin and (2) lunch with capsaicin (CAPS). The macronutrient composition (energy percentage) of the lunches was 60% carbohydrates, 10% protein and 30% fat. During 3 h after the lunch diet-induced thermogenesis was measured. Furthermore, anchored 100 mm visual analogue scales on the appetite profile were collected (t = 0, 30, 60, 120, 150, 180 and 240) and blood samples were taken for analysis of GLP-1, PYY, and ghrelin concentrations (t = 0, 45, 60, 120, and 180). RESULTS: Satiety and EE were not different after CAPS lunch as compared to the control lunch. Fifteen minutes after lunch CAPS lunch increased GLP-1 (p < 0.05) and tended to decrease ghrelin (p = 0.07) as compared to the control lunch. PYY responses were not different between the CAPS lunch and the control lunch. CONCLUSIONS: An acute lunch containing capsaicin had no effect on satiety, EE, and PYY, but increased GLP-1 and tended to decrease ghrelin

The preview study: Metabolic outcomes in overweight, prediabetic individuals after an 8-week low calorie diet

Abstracts / Journal of Nutrition & Intermediary Metabolism 8 (2017)Peer reviewe

Lack of effect of high-protein vs. high-carbohydrate meal intake on stress-related mood and eating behavior

<p>Abstract</p> <p>Background</p> <p>Consumption of meals with different macronutrients, especially high in carbohydrates, may influence stress-related eating behavior. We aimed to investigate whether consumption of high-protein vs. high-carbohydrate meals influences stress-related mood, food reward, i.e. 'liking' and 'wanting', and post-meal energy intake.</p> <p>Methods</p> <p>Participants (n = 38, 19m/19f, age = 25 ± 9 y, BMI = 25.0 ± 3.3 kg/m²) came to the university four times, fasted, once for a stress session receiving a high-protein meal, once for a rest session receiving a high-protein meal, once for a stress session receiving a high-carbohydrate meal and once for a rest session receiving a high-carbohydrate meal (randomized cross-over design). The high-protein and high-carbohydrate test meals (energy percentage protein/carbohydrate/fat 65/5/30 vs. 6/64/30) matched for energy density (4 kJ/g) and daily energy requirements (30%). Stress was induced using an ego-threatening test. Pre- and post-meal 'liking' and 'wanting' (for bread, filling, drinks, dessert, snacks, stationery (non-food alternative as control)) was measured by means of a computer test. Following the post-meal 'wanting' measurement, participants received and consumed their wanted food items (post-meal energy intake). Appetite profile (visual analogue scales), mood state (Profile Of Mood State and State Trait Anxiety Inventory questionnaires), and post-meal energy intake were measured.</p> <p>Results</p> <p>Participants showed increased feelings of depression and anxiety during stress (P < 0.01). Consumption of the test meal decreased hunger, increased satiety, decreased 'liking' of bread and filling, and increased 'liking' of placebo and drinks (P < 0.0001). Food 'wanting' decreased pre- to post-meal (P < 0.0001). The high-protein vs. high-carbohydrate test meal induced lower subsequent 'wanting' and energy intake (1.7 ± 0.3 MJ vs. 2.5 ± 0.4 MJ) only in individuals characterized by disinhibited eating behavior (factor 2 Three Factor Eating Questionnaire, n = 16), during rest (P ≤ 0.01). This reduction in 'wanting' and energy intake following the high-protein meal disappeared during stress.</p> <p>Conclusions</p> <p>Consumption of a high-protein vs. high-carbohydrate meal appears to have limited impact on stress-related eating behavior. Only participants with high disinhibition showed decreased subsequent 'wanting' and energy intake during rest; this effect disappeared under stress. Acute stress overruled effects of consumption of high-protein foods.</p> <p>Trial registration</p> <p>The study was registered in the Dutch Trial Register (<a href="http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2040">NTR1904</a>). The protocol described here in this study deviates from the trial protocol approved by the Medical Ethical Committee of the Maastricht University as it comprises only a part of the approved trial protocol.</p

Metabolic responses to the acute ingestion of two commercially available carbonated beverages: A pilot study

<p>Abstract</p> <p>Background</p> <p>The purpose of this placebo-controlled, double-blind cross-over study was to compare the effects of two commercially available soft drinks on metabolic rate.</p> <p>Methods</p> <p>After giving informed consent, twenty healthy men and women were randomly assigned to ingest 12 ounces of Celsius™ and, on a separate day, 12 ounces of Diet Coke®. All subjects completed both trials using a randomized, counterbalanced design. Metabolic rate (via indirect calorimetry) and substrate oxidation (via respiratory exchange ratio) were measured at baseline (pre-ingestion) and at the end of each hour for 3 hours post-ingestion.</p> <p>Results</p> <p>Two-way ANOVA revealed a significant interaction (p < 0.001) between trials in metabolic rate. Scheffe post-hoc testing indicated that metabolic rate increased by 13.8% (+ 0.6 L/min, p < 0.001) 1 hr post, 14.4% (+0.63 L/min, p < 0.001) 2 hr post, and 8.5% (+0.37 L/min, p < 0.004) 3 hr post Celsius™ ingestion. In contrast, small (~4–6%) but statistically insignificant increases in metabolic rate were noted following Diet Coke^®ingestion. No differences in respiratory exchange ratio were noted between trials.</p> <p>Conclusion</p> <p>These preliminary findings indicate Celsius™ has thermogenic properties when ingested acutely. The effects of repeated, chronic ingestion of Celsius™ on body composition are unknown at this time.</p

Dose-Dependent Associations of Dietary Glycemic Index, Glycemic Load, and Fiber With 3-Year Weight Loss Maintenance and Glycemic Status in a High-Risk Population : A Secondary Analysis of the Diabetes Prevention Study PREVIEW

OBJECTIVE To examine longitudinal and dose-dependent associations of dietary glycemic index (GI), glycemic load (GL), and fiber with body weight and glycemic status during 3-year weight loss maintenance (WLM) in adults at high risk of type 2 diabetes. RESEARCH DESIGN AND METHODS In this secondary analysis we used pooled data from the PREVention of diabetes through lifestyle Intervention and population studies in Europe and around the World (PREVIEW) randomized controlled trial, which was designed to test the effects of four diet and physical activity interventions. A total of 1,279 participants with overweight or obesity (age 25-70 years and BMI >= 25 kg . m(-2)) and prediabetes at baseline were included. We used multiadjusted linear mixed models with repeated measurements to assess longitudinal and dose-dependent associations by merging the participants into one group and dividing them into GI, GL, and fiber tertiles, respectively. RESULTS In the available-case analysis, each 10-unit increment in GI was associated with a greater regain of weight (0.46 kg . year(-1); 95% CI 0.23, 0.68; P < 0.001) and increase in HbA(1c). Each 20-unit increment in GL was associated with a greater regain of weight (0.49 kg . year(-1); 0.24, 0.75; P < 0.001) and increase in HbA(1c). The associations of GI and GL with HbA(1c) were independent of weight change. Compared with those in the lowest tertiles, participants in the highest GI and GL tertiles had significantly greater weight regain and increases in HbA(1c). Fiber was inversely associated with increases in waist circumference, but the associations with weight regain and glycemic status did not remain robust in different analyses. CONCLUSIONS Dietary GI and GL were positively associated with weight regain and deteriorating glycemic status. Stronger evidence on the role of fiber is needed.Peer reviewe