Spread it on thick? Relative effects of condiment addition and slice thickness on eating rate of bread.

Manipulating eating rate (ER) by food properties may enhance or reduce food intake. Within composite foods, such as bread with condiments, the shape of carrier food and the use of condiments are known to influence ER. However, not much is known about their quantitative impacts and interactions. This study investigates the effect of bread slice thickness and addition of condiment on oral processing (ER, chews per g, bite size). In a full factorial design, 30 participants (BMI 21.6 ± 2.0 kg m-2, 23.3 ± 2.1 year) consumed two types of bread (wholewheat (WB); and sourdough (SB)), in three different slice thicknesses (1, 2, 4 cm), with three conditions of margarine addition (0, 2, 4 g per slice of 28 cm2). The results showed that addition of margarine in both breads led to ∼50% higher ER in a non-linear fashion mainly via less chews per g (all P < 0.001). Increasing bread slice thickness in both breads, resulted in ∼15% higher ER, mainly via larger bite sizes (all P < 0.001). The addition of margarine reduced or overruled the effect of slice thickness on all oral processing characteristics (interaction margarine × slice thickness, all P < 0.01). Perceived sensory dryness showed a strong negative correlation with ER. In conclusion, this study highlighted the importance of bread slice thickness, amount of a condiment, and their interactions in controlling ER. Lubrication of the dry crumbs was a main mechanism in controlling ER in this study. These insights can help the design of products with lower ER.

Contributions of viscosity and friction properties to oral and haptic texture perception of iced coffees.

Creaminess is affected by bulk properties (i.e. viscosity) and surfaces properties (i.e. friction). This study aimed (i) to assess contributions of viscosity and friction properties to creaminess, thickness and slipperiness perception; and (ii) to compare oral and haptic thickness and slipperiness perception of iced coffees. Three iced coffees differing in viscosity and friction properties were prepared: low viscosity - high friction (LV-HF); low viscosity - low friction (LV-LF) and high viscosity - low friction (HV-LF) iced coffee. Viscosity of iced coffees was adjusted by addition of maltodextrin, and viscosity of HV-LF was 2.5 times higher than that of LV-HF and LV-LF (10 vs. 4 mPa s at 100 s-1). Friction coefficients of LV-LF were reduced by addition of polyethylene glycol (PEG, Mw 6000), and were up to 25% lower than those of LV-HF. Forty-seven untrained panellists (18-27 years) performed two-alternative forced choice (2-AFC) and rank-rating tests to compare creaminess by oral assessment, and thickness and slipperiness by oral and haptic assessment. Results from 2-AFC and rank-rating congruently showed that HV-LF was creamier, thicker and more slippery than LV-HF and LV-LF, both orally and haptically. LV-LF was orally perceived as less creamy and less thick, but haptically as more slippery than LV-HF. Creaminess was more strongly correlated to thickness than to slipperiness. Oral and haptic evaluation of thickness was congruent, whereas differences between oral and haptic slipperiness evaluation were product-dependent. We conclude that increasing viscosity enhances creaminess, whereas increasing lubrication is not necessarily sufficient to increase creaminess in iced coffees.

Salt Promotes Passive Overconsumption of Dietary Fat in Humans.

BACKGROUND: Excess fat consumption has been linked to the development of obesity. Fat and salt are a common and appetitive combination in food; however, the effect of either on food intake is unclear. Fat taste sensitivity has been negatively associated with dietary fat intake, but how fat taste sensitivity influences the intake of fat within a meal has, to our knowledge, not yet been investigated. OBJECTIVES: Our objectives were, first, to investigate the effects of both fat and salt on ad libitum food intake and, second, to investigate the effects of fat taste sensitivity on satiation responses to fat and whether this was affected by salt. METHODS: Forty-eight healthy adults [16 men and 32 women, aged 18-54 y, body mass index (kg/m(2)): 17.8-34.4] were recruited and their fat taste sensitivity was measured by determination of the detection threshold of oleic acid (18:1n-6). In a randomized 2 × 2 crossover design, participants attended 4 lunchtime sessions after a standardized breakfast. Meals consisted of elbow macaroni (56%) with sauce (44%); sauces were manipulated to be1) low-fat (0.02% fat, wt:wt)/low-salt (0.06% NaCl, wt:wt),2) low-fat/high-salt (0.5% NaCl, wt:wt),3) high-fat (34% fat, wt:/wt)/low-salt, or4) high-fat/high-salt. Ad libitum intake (primary outcome) and eating rate, pleasantness, and subjective ratings of hunger and fullness (secondary outcomes) were measured. RESULTS: Salt increased food and energy intakes by 11%, independent of fat concentration (P= 0.022). There was no effect of fat on food intake (P= 0.6), but high-fat meals increased energy intake by 60% (P< 0.001). A sex × fat interaction was found (P= 0.006), with women consuming 15% less by weight of the high-fat meals than the low-fat meals. Fat taste sensitivity was negatively associated with the intake of high-fat meals but only in the presence of low salt (fat taste × salt interaction on delta intake of high-fat - low-fat meals;P= 0.012). CONCLUSIONS: The results suggest that salt promotes passive overconsumption of energy in adults and that salt may override fat-mediated satiation in individuals who are sensitive to the taste of fat. This trial was registered at the Australian New Zealand Clinical Trials Registry (www.anzctr.org.au) as ACTRN12615000048583.

The influence of a high-fat meal on fat taste thresholds.

A high-fat diet for four weeks has been shown to attenuate fat taste sensitivity in healthy weight individuals. However, there is minimal evidence as to whether a single high-fat meal immediately prior to fat taste threshold testing has an effect on thresholds. Therefore, the aim of the study was to determine the effect of a high-fat meal immediately prior to detection threshold testing for oleic acid (C18:1). Thirty-two participants (15 males, 17 females, aged 39.1 ± 3.1 years, Body Mass Index 23.1 ± 0.7 kg/m(2)) attended three laboratory sessions. In each session, participants were randomly assigned to one of three different types of breakfast: a high-fat (60% energy from fat), or low-fat (20% energy from fat) or macronutrient balanced (33% energy from fat) frittata. Fat taste thresholds were evaluated using ascending forced choice triangle tests on two occasions each day; once one-hour post breakfast and then one-hour post the completion of the first threshold test. There was no effect of breakfast type on fat taste detection thresholds for the first testing session of each day (P = 0.288), or the second testing session of each day (P = 0.754). There was also no effect of breakfast within each day (day 1: P = 0.198, day 2: P = 0.199, day 3: P = 0.125). There was no effect of macronutrient composition on the ability of participants to rank the level of fat in food (P = 0.345), or preference for the level of fat in food (P = 0.187-0.868). This study provides preliminary evidence that the composition of the meal consumed by a participant immediately prior to testing does not affect fat taste thresholds.

Dietary sodium intake and overweight and obesity in children and adults: a protocol for a systematic review and meta-analysis.

BACKGROUND: Overweight and obesity in children and adults is a major public health concern. Emerging evidence suggests dietary sodium intake may be associated with obesity. This systematic review and meta-analysis will aim to (i) assess the relation between dietary sodium intake and measures of adiposity in children and adults and (ii) examine the relation between sodium intake and sugar-sweetened beverage (SSB) consumption, which is a known risk factor for obesity. METHODS/DESIGN: An electronic search will be conducted using Medline Complete, CINAHL, Scopus, Embase and Cochrane central register of controlled trials (CENTRAL). The search strategy will identify published peer-reviewed articles that report on dietary sodium and either a marker of adiposity or SSB consumption. Only human studies (ages >1 year) in English will be included, and no limits will be placed on publication date. No restrictions will be placed on the method of sodium intake assessment. Cross-sectional, prospective studies, and randomised controlled trials with a duration of ≥ 3 months will be included. Studies with participants with renal disease, cancer, type 1 diabetes or heart failure or who are pregnant will be excluded. To assess the quality of studies, the Cochrane's Collaboration tool for assessing risk of bias in randomised trials will be used for randomised controlled trials (RCTs), and the modified Newcastle-Ottawa Scale will be used for cross-sectional and prospective studies. Meta-analysis will be used to assess the relation of sodium intake with two primary outcomes: (i) BMI and body weight in adults and BMI z-score in children and (ii) weight category (i.e. healthy weight vs. overweight/obese). For any outcomes in which meta-analysis is not possible, we will present data as a systematic review. Findings will be grouped and reported separately for children and adolescents (ages 1-17 years) and adults (ages >18 years). DISCUSSION: This review and meta-analysis will provide insight into the relation between dietary sodium intake and overweight and obesity. This information can be used to inform public health policies which target population sodium consumption. SYSTEMATIC REVIEW REGISTRATION: Prospero CRD42015016440.

Dietary fat restriction increases fat taste sensitivity in people with obesity.

OBJECTIVE: Individuals with obesity may be less sensitive to the taste of fat, and it is hypothesized that this is due to excess dietary fat intake. This study assessed the effect of a 6-week low-fat (LF) or portion control (PC) diet matched for weight loss on fat taste thresholds, fat perception, and preference in people with overweight/obesity. METHODS: Participants (n = 53) completed a randomized dietary intervention and consumed either a LF diet (25% fat) or PC diet (33% fat) for 6 weeks. Fat taste thresholds (lowest detectable fat concentration), fat perception (discrimination ability), preference, and anthropometry were assessed at baseline and week 6. RESULTS: Consumption of a LF diet (n = 26) and PC diet (n = 27) reduced participants' weight (P < 0.001), with no significant differences between groups (LF, -2.9%, PC, -2.7%). Both diets resulted in a decrease in fat taste thresholds (P = 0.014), and the effect tended to be stronger in the LF diet vs. the PC diet (P = 0.060). The ability to perceive different fat concentrations in foods was increased after the LF diet only (P = 0.017); however, food preference did not change on either diet. CONCLUSIONS: A PC and LF diet both increase fat taste sensitivity in people with overweight/obesity, with the strongest effect after the LF diet.

Effects of Salt and Fat Combinations on Taste Preference and Perception.

Fat and salt are a common and attractive combination in food and overconsumption of either is associated with negative health outcomes. The major aim was to investigate contributions and interactions of salt and fat on taste pleasantness and perception. The minor aim was to investigate individual fat taste sensitivity (detection threshold of oleic acid [C18:1]) on pleasantness for fat. In a complete factorial design, 49 participants (18-54 years, 12 males) tasted tomato soups with 4 different fat concentrations (0-20%) and 5 different salt concentrations (0.04-2.0%). The preferred concentration and the discrimination ability for both fat and salt were determined by ranking tests. Results show that salt and fat affected pleasantness separately (P < 0.01), with salt having the strongest effect. Fat concentrations 0%, 5%, and 10% did not differ in pleasantness, whereas 20% was less pleasant (P < 0.05). There were no interactions for fat and salt on pleasantness or saltiness and fattiness intensity. Fat taste sensitive participants preferred lower fat concentrations than less sensitive participants (P = 0.008). In conclusion, the strong effect of salt on pleasantness in this study suggests that salt, rather than fat, play a major role in the attraction to savory fatty foods.

The Relationships Between Common Measurements of Taste Function.

BACKGROUND: There are five common, independent measures used to characterize taste function in humans: detection and recognition thresholds (DT and RT), suprathreshold intensity ratings of prototypical tastants, propylthiouracil (PROP) bitterness intensity, and fungiform papillae (FP) number. METHODS: We employed all five methods to assess taste function of 65 women (21.5 ± 4 years, BMI 22.3 ± 2.8 kg/m2). Pearson correlation coefficients were calculated between the different measures. RESULTS: The DT and RT were positively correlated for sweet, bitter, sour, and umami (p < 0.05), but not for salt. The DT or RT did not correlate with suprathreshold intensity ratings, except for umami (suprathreshold intensity and RT: r = -0.32, p = 0.009). FP number did not correlate with any measurement of taste function. PROP bitterness intensity ratings did not correlate with any measurement of taste function, except for suprathreshold ratings for saltiness (r = 0.26, p = 0.033). CONCLUSION: As most of the individual measures of taste function did not correlate with each other, with exception of the two threshold measures, we conclude that there are multiple perceptual phases of taste, with no single measure able to represent the sense of taste globally.

Slow food: sustained impact of harder foods on the reduction in energy intake over the course of the day.

BACKGROUND: Previous research has shown that oral processing characteristics like bite size and oral residence duration are related to the satiating efficiency of foods. Oral processing characteristics are influenced by food texture. Very little research has been done on the effect of food texture within solid foods on energy intake. OBJECTIVES: The first objective was to investigate the effect of hardness of food on energy intake at lunch, and to link this effect to differences in food oral processing characteristics. The second objective was to investigate whether the reduction in energy intake at lunch will be compensated for in the subsequent dinner. DESIGN: Fifty subjects (11 male, BMI: 21±2 kg/m2, age: 24±2 y) participated in a cross-over study in which they consumed ad libitum from a lunch with soft foods or hard foods on two separate days. Oral processing characteristics at lunch were assessed by coding video records. Later on the same days, subjects consumed dinner ad libitum. RESULTS: Hard foods led to a ∼13% lower energy intake at lunch compared to soft foods (P<0.001). Hard foods were consumed with smaller bites, longer oral duration per gram food, and more chewing per gram food compared to the soft foods (P<0.05). Energy intake at dinner did not differ after both lunches (P = 0.16). CONCLUSIONS: Hard foods led to reduced energy intake compared to soft foods, and this reduction in energy intake was sustained over the next meal. We argue that the differences in oral processing characteristics produced by the hardness of the foods explain the effect on intake. The sustained reduction in energy intake suggests that changes in food texture can be a helpful tool in reducing the overall daily energy intake.

Consumption with large sip sizes increases food intake and leads to underestimation of the amount consumed.

BACKGROUND: A number of studies have shown that bite and sip sizes influence the amount of food intake. Consuming with small sips instead of large sips means relatively more sips for the same amount of food to be consumed; people may believe that intake is higher which leads to faster satiation. This effect may be disturbed when people are distracted. OBJECTIVE: The objective of the study is to assess the effects of sip size in a focused state and a distracted state on ad libitum intake and on the estimated amount consumed. DESIGN: In this 3×2 cross-over design, 53 healthy subjects consumed ad libitum soup with small sips (5 g, 60 g/min), large sips (15 g, 60 g/min), and free sips (where sip size was determined by subjects themselves), in both a distracted and focused state. Sips were administered via a pump. There were no visual cues toward consumption. Subjects then estimated how much they had consumed by filling soup in soup bowls. RESULTS: Intake in the small-sip condition was ∼30% lower than in both the large-sip and free-sip conditions (P<0.001). In addition, subjects underestimated how much they had consumed in the large-sip and free-sip conditions (P<0.03). Distraction led to a general increase in food intake (P = 0.003), independent of sip size. Distraction did not influence sip size or estimations. CONCLUSIONS: Consumption with large sips led to higher food intake, as expected. Large sips, that were either fixed or chosen by subjects themselves led to underestimations of the amount consumed. This may be a risk factor for over-consumption. Reducing sip or bite sizes may successfully lower food intake, even in a distracted state.

Effect of salt intensity in soup on ad libitum intake and on subsequent food choice.

The effect of salt intensity on ad libitum intake of tomato soup was investigated when soup was served as a first course and as a second course. Also the effect of salt intensity in soup on subsequent sweet vs. savory choice of sandwich fillings was investigated. Forty-three healthy subjects consumed ad libitum a low-salt (LS), ideal-salt (IS) and high-salt (HS) tomato soup in both meal settings. The salt concentrations were selected on an individual basis, in a way that IS was most pleasant and LS and HS were similar in pleasantness. The ad libitum intake of IS soup was higher than that of LS and HS soup, and the ad libitum intake of LS soup was higher than that of HS soup. The meal setting, soup as a first or as a second course, did not affect ad libitum intake. Salt intensity in soup did not predict sweet vs. savory choice of fillings in grams or energy, although most sodium from fillings was consumed after intake of HS soup. In conclusion, a higher salt intensity lead to lower ad libitum intake of soup similar in palatability (LS vs. HS). In addition, salt intensity in soup does not predict sweet vs. savory food choice.

Both longer oral sensory exposure to and higher intensity of saltiness decrease ad libitum food intake in healthy normal-weight men.

Orosensory exposure to sweetness has been shown to be important in satiation, whereas the effect of exposure to a salty taste on satiation is not known. The primary objective was to investigate the effect of orosensory exposure time to and intensity of saltiness in soup on ad libitum intake. The secondary objective was to investigate the effect of intensity on bite size. Fifty-five healthy men consumed ad libitum from both a low-salt (LS) and a high-salt (HS) creamy tomato soup in 2 exposure time conditions ("long" and "short") and a free condition ("free"). Bites were administered and controlled via a pump. In the long condition, bites of 5 g were administered in 2 s at intervals of 5 s (exposure time: 24 s/min). In the short condition, bites of 15 g were administered in 3 s at intervals of 15 s (exposure time: 12 s/min). The eating rate was equal in the long and short conditions (60 g/min). In the free condition, participants adjusted their bite sizes at intervals of 15 s. The short condition resulted in ~34% higher ad libitum intake compared to the long condition (P < 0.001); there was no interaction with intensity. Ad libitum intake of HS soup was ~9% lower than LS soup (P < 0.001). The free condition showed that HS soup was consumed with smaller bite sizes during the first half of the intake period (P < 0.05). Longer orosensory exposure and higher saltiness intensity both decreased food intake, although orosensory exposure had more impact than intensity. Prolonging the orosensory exposure per food unit may be helpful to reduce food intake.

A salt reduction of 50% in bread does not decrease bread consumption or increase sodium intake by the choice of sandwich fillings.

Bread is a major contributor to sodium intake in many countries. Reducing the salt (NaCl) content in bread might be an effective way to reduce overall sodium intake. The objectives of this study were to examine the effects of gradually lowering the salt content in brown bread, with and without flavor compensation (KCl and yeast extract), on bread consumption and sodium intake compensation by choice of sandwich fillings. A total of 116 participants (age: 21 ± 3 y; BMI: 22 ± 2 kg/m²) consumed a buffet-style breakfast on weekdays for 4 wk. Participants received either regular bread (control group: n = 39), bread whose salt content was gradually lowered each week by 0, 31, 52, and 67% (reduced group: n = 38), or bread whose salt content was also gradually lowered each week but which was also flavor compensated (compensated group: n = 39). A reduction of up to 52% of salt in bread did not lead to lower consumption of bread compared to the control (P = 0.57), whereas less bread was consumed when salt was reduced by 67% (P = 0.006). When bread was flavor compensated, however, a reduction of 67% did not lead to lower consumption (P = 0.69). Salt reduction in bread (with and without flavor compensation) did not induce sodium intake compensation (P = 0.31). In conclusion, a salt reduction of up to 52% in bread or even up to 67% in flavor-compensated bread neither affected bread consumption nor choice of sandwich fillings.

Effect of salt intensity on ad libitum intake of tomato soup similar in palatability and on salt preference after consumption.

Sensory properties of food play an important role in satiation. Studies on the effect of taste intensity on satiation show conflicting results. This may be due to the notion that in these studies taste intensity and palatability were confounded. The objective of this study was to investigate the effect of salt intensity of tomato soup on ad libitum intake (satiation), while controlling for palatability on an individual basis. Forty-eight subjects consumed both a low-salt (LS) and high-salt (HS) soup ad libitum from a self-refilling bowl. The results showed no difference between LS and HS soup in ad libitum intake, eating rate, changes in appetite ratings, and changes in hedonic ratings after intake. After intake of HS soup, LS soup was perceived as more bland than before intake of HS soup. After intake of LS soup, HS soup was perceived as more salt intense than before intake of LS soup. In conclusion, this study found no effect of salt intensity on satiation of tomato soups that were similar in palatability. During consumption, subjects adapted quickly to the exposed salt intensity as contrasting salt intensities were rated further from the ideal salt intensity and therefore perceived as less pleasant after consumption.