Association between consumption of black tea and iron status in adult Africans in the North West Province: The THUSA study

The association between black tea consumption and iron status was investigated in a sample of African adults participating in the cross-sectional THUSA (Transition and Health during Urbanization of South Africans) study in the North West Province, South Africa. Data were analysed from 1605 apparently healthy adults aged 15-65 years by demographic and FFQ, anthropometric measurements and biochemical analyses. The main outcome measures were Hb and serum ferritin concentrations. No associations were seen between black tea consumption and concentrations of serum ferritin (men P=0.059; women P=0.49) or Hb (men P=0.33; women P=0.49). Logistic regression showed that tea consumption did not significantly increase risk for iron deficiency (men: OR 1.36; 95 % CI 0.99, 1.87; women: OR 0.98; 95 % CI 0.84, 1.13) nor for iron deficiency anaemia (men: OR 1.28: 95 % Cl 0.84, 1.96; women: OR 0.93; 95 % Cl 0.78, 1.11). Prevalence of iron deficiency and iron deficiency anaemia was especially high in women: 21.6 and 14.6 %, respectively. However, the likelihood of iron deficiency and iron deficiency anaemia was not significantly explained by tea consumption in sub-populations which were assumed to be at risk for iron deficiency. Regression of serum ferritin levels on tea consumption in women : 40 years, adults with a daily iron intak

Expected satiation after repeated consumption of low- or high-energy-dense soup

We investigated whether repeated consumption of a low-energy-dense (LED; 208 kJ/100 g) or high-energy-dense (HED; 645 kJ/100 g) soup modifies expectations relating to the satiating capacity of the food, and its subsequent intake. In study 1, participants consumed either a novel-flavoured LED (n 32; 21 (SD 1.6) years, BMI 21-4 (SD 1.6) kg/m(2)) or HED soup (n 32; 21 (SD 1-6) years, BMI 21.3 (SD 1.7) kg/m(2)). Soup was served in a fixed amount on days 1-4 and ad libitum on day 5. 'Expected satiation' was measured on days 1, 2 and 5. Expected satiation did not change after repeated consumption of the LED or HED soup. Ad libitum intake did not differ between the LED (461 (SD 213) g) and HED soup (391 (SD 164) g). Only on day 1, expected satiation was higher for the HED soup than for the LED soup (P=0.03), suggesting a role for sensory attributes in expected satiation. In study 2, thirty participants (21 (SD 1-6) years, BMI 21-3 (SD 1.7) kg/m2) performed a single measurement of expected satiation of the LED and HED soup, and four commercially available types of soup. Ratings on sensory attributes were associated with expected satiation. Results on expected satiation coincided with those of study 1. Thickness and intensity of taste were independently associated with expected satiation. Expectations may initially rely on sensory attributes and previous experiences, and are not easily changed

Texture, energy density & learning : implications for food intake

Introduction Food texture has been shown to be an important factor in the regulation of food (energy) intake. Liquid foods e.g. elicit weaker satiety responses than solid foods with a similar energy content, and texture affects satiation, i.e. ad libitum food intake. Whether theeffect of food texture on food intake stays the same over repeated exposure requires further investigation. Aim The aim of this thesis is to investigate the role of food texture in learned satiation. We assessed the effect of texture on changes in ad libitum intake and expected satiation after repeated consumption of foods with different energy density. Methods We conducted a series of learning experiments with healthy young adults. Participants repeatedly consumed a low-energy-dense (LED) and a high-energy-dense (HED) yogurt, which were either low (n=24) or high (n=22) in viscosity in one study; and consumed with a straw (liquid yogurt, n=34) or with a spoon (liquid yogurt, n=36; semi-solid yogurt, n=35) in a second study. Next, we investigated changes in expected satiation and intake after repeated consumption of a LED soup (n=32) or a HED soup (n=32) with similar appearance; and of a liquid and a semi-solid custard with a similar energy density (n=53). Additionally, we assessed the effect of texture, flavour and means of consumption on expected satiation of iso-caloric dairy products in 3 single-meal experiments. Finally, we served a fixed amount of a LED or HED food - either liquid or semi-solid - at each meal on 3 consecutive days, and measured ad libitum buffet intake directly after consumption of these foods (n=27). Results Texture clearly affected satiation:ad libitum intake was up to 30% higher of liquid foods when compared with semi-solids foods in all experiments (p Participants were able to learn about the foods’ satiating capacity after repeated consumption. Ad libitum intake of a HED high-viscous yogurt decreased and was 10% lower compared with a LED high-viscous yogurt after repeated consumption, while intake of a LED and HED low-viscous yogurt did not differ (interaction effect: p=0.04). We also observed thatappetite sensations changed when participants repeatedly consumed a liquid and semi-solid custard with a similar energy density (pad libitum buffet after repeated consumption of a LED food (from 1745 ± 577 to 1979 ± 567 kcal), while their intake did not change after a HED food (interaction effect: p=0.02). This increase was observed irrespective of the texture of the test foods. Ad libitum intake was higher of liquid foods when compared with semi-solid foods, also after learning about the energy content of a food over repeated exposure. Participants did not adjust their intake and expected satiation consistently. Intake did not change when participants consumed a LED and a HED yogurt with a straw or with a spoon. We also did not observe profound changes in the expected satiation of a LED and HED soup or a liquid and semi-solid custard. Conclusions Healthy young adults learned about the foods’ satiating capacity after repeated consumption. Changes in intake and expectations in response to learning did not depend on food texture. Food intake and expected satiation were not easily changed. The effect of food texture on satiation is important in the regulation of food intake, also after repeated exposure.</p

Texture and Diet Related Behavior: A Focus on Satiation and Satiety

In view of the increasing numbers in overweight and obesity, insight in food intake regulation is necessary. Food intake is regulated by sensory, cognitive, post-ingestive, and post-absorptive processes. Food properties, such as energy density, macronutrient composition, volume, and form, influence the satiating capacity of a food. This chapter focuses on the role of food texture in food intake regulation. Texture is an essential part of the whole spectrum of sensory properties of a food. Several studies showed that liquid foods elicit weaker suppressive appetite responses and a weaker compensatory response in energy intake than solid or semisolid foods. The mechanisms underlying the effect of texture on satiety are not well understood. Beverages might engage thirst mechanisms and not hunger mechanisms. Food properties such as viscosity and texture could affect chewing, oro-gastric handling of foods, and absorption. Other factors that play a role are beliefs about the satiating capacity of a food, sensory specific satiety, eating rate, gastric emptying, and learned associations between texture and metabolic consequences. One of the mechanisms involved could be the oral sensory exposure time. A longer oral exposure time gives the sensory receptors in the oral cavity more time to respond to the food. Liquid calories facilitate energy intake. This knowledge can be useful in both the overweight and underweight situation

Learning about the energy density of liquid and semi-solid foods

BACKGROUND: People learn about a food's satiating capacity by exposure and consequently adjust their energy intake. OBJECTIVE: To investigate the effect of energy density and texture on subsequent energy intake adjustments during repeated consumption. DESIGN: In a randomized crossover design, participants (n = 27, age: 21 +/- 2.4 years, body mass index: 22.2 +/- 1.6 kg m(-2)) repeatedly consumed highly novel foods that were either low-energy-dense (LE: 30 kcal per 100 g) or high-energy-dense (HE: 130 kcal per 100 g), and either liquid or semi-solid, resulting in four product conditions. In each condition, a fixed portion of test food was consumed nine times as an obligatory part of breakfast, lunch and dinner on 3 consecutive days. All meals continued with an ad libitum buffet; food items for evening consumption were provided and the intake (kcal per day) was measured. RESULTS: Buffet intake depended on energy density and day of consumption of the test foods (day*energy interaction: P = 0.02); daily buffet intake increased from day 1 (1745 +/- 577 kcal) to day 3 (1979 +/- 567 kcal) in the LE conditions; intake did not change in the HE conditions (day 1: 1523 +/- 429 kcal, day 3: 1589 +/- 424 kcal). Food texture did not affect the intake (P = 0.56). CONCLUSIONS: Intake did depend on energy density of the test foods; participants increased their buffet intake over days in response to learning about the satiating capacity of the LE foods, but did not change buffet intake over days when repeatedly consuming a HE food as part of their meal. The adjustments in intake were made irrespective of the food texture

Repeated consumption of a large volume of liquid and semi-solid foods increases ad libitum intake, but does not change expected satiety

Food intake and a food’s expected satiating effect initially rely on sensory attributes. People will learn about the food’s satiating capacity by exposure. We investigated whether repeated consumption changed the expected satiety effects and intake of iso-energetic liquid and semi-solid foods. In a randomised cross-over study, participants (n = 53; age: 21 ± 2.9 y; BMI: 21.8 ± 2.0 kg/m2) consumed one of two iso-energetic dairy foods (liquid or semi-solid) for breakfast in each 5-day test condition. Expectations regarding satiety were measured on days 1, 2, and 5. Foods were offered ad libitum on days 1 and 5 and in a fixed volume on days 2–4. Appetite sensations were rated up to 180 min after the start of the session on fixed time points. Expected satiety effects of the semi-solid food were higher than of the liquid food on all days (p <0.0001). Ad libitum intake of the liquid food was higher than of the semi-solid food on day 1 (liquid: 391 ± 177 g, semi-solid: 277 ± 98 g; p <0.0001) and day 5 (liquid: 477 ± 161 g, semi-solid: 375 ± 148 g; p <0.0001). On day 2, hunger was rated lower and fullness rated higher after the semi-solid compared with the liquid food; on day 4, no differences were observed (significant product* exposure interaction AUC). Changes in hunger and fullness indicated that the fixed volumes of liquid and solid food were perceived to be equally satiating after repeated consumption, but this did not result in the anticipated changes: expected satiety effects remained lower, and ad libitum intake higher for the liquid compared with the semi-solid food. The effect of texture on a food’s expected satiety effects and its ad libitum intake appears to be large, also after repeated consumption. Expectations based on sensory cues are not easily changed

Intake during repeated exposure to low- and high-energy-dense yogurts by different means of consumption

Background: An important question in the regulation of energy intake is whether dietary learning of energy content depends on the food's characteristics, such as texture. Texture might affect the duration of sensory exposure and eating rate. Objective: The objective was to investigate whether a long sensory exposure, due to differences in means of consumption and in viscosity, enhances learned associations between sensory signals and metabolic consequences and hence facilitates energy intake compensation. Design: A total of 105 healthy young adults with a mean (±SD) age of 22 ± 3 y and a body mass index (in kg/m2) of 21.6 ± 1.7 participated in a parallel intervention in 3 groups: liquid yogurt with a straw (liquid/straw; n = 34), liquid yogurt with a spoon (liquid/spoon; n = 36), or semisolid yogurt with a spoon (semisolid/spoon; n = 35). Novel flavored yogurts were offered ad libitum for breakfast in 2 energy densities: low (215 kJ/100 g) and high (600 kJ/100 g). Subjects were repeatedly exposed to the yogurt products (10 times), and yogurt intake was measured. Results: Intakes (P = 0.01) and eating rates (P = 0.01) were highest in the liquid/straw group. Average intakes over 10 exposures were 575 ± 260 g for liquid/straw, 475 ± 192 g for liquid/spoon, and 470 ± 223 g for semisolid/spoon; average eating rates were 132 ± 83 g/min for liquid/straw, 106 ± 53 g/min for liquid/spoon, and 105 ± 88 g/min for semisolid/spoon. No significant interaction for intake between intervention group, energy density, and repeated exposure was observed, and intakes of the low- and high-energy-dense yogurts did not change over time in any of the intervention groups. Conclusions: We observed no energy intake compensation after repeated exposure to yogurt products. Differences in ad libitum yogurt intake could be explained by eating rate, which was affected by the different means of consumption. This trial was registered with the Dutch trial registration at http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=1853 as NTR1853

Effect of viscosity on learned satiation

A higher viscosity of a food leads to a longer orosensory stimulation. This may facilitate the learned association between sensory signals and metabolic consequences. In the current study we investigated the effect of viscosity on learned satiation. In two intervention groups a low viscosity (LV) yogurt (n=24) and a high viscosity (HV) yogurt (n=22) was offered ad libitum for breakfast. In a learning period of 4 weeks, subjects consumed ad libitum a novel flavoured high energy density (HED) yogurt (150 kcal/100 g) or low energy density (LED) yogurt (50 kcal/100 g), with 10 exposures to each yogurt on alternate days. Over the repeated exposures, an interaction effect of exposure timeenergyviscosity on intake was seen (F(1,771)=4.12; p=0.04). In the HV intervention group a borderline significant interaction between exposure and energy density was observed (F(1,369)=3.61; p=0.06); after 10 exposures, the LED yogurt resulted in a 46+/-16 g higher intake compared with the HED yogurt. In the LV group, no significant interaction between exposure and energy density was seen (F(1,401)=1.04; p=0.31); after 10 exposures intake difference between the LED and HED yogurts was only 1.5+/-15 g. These results suggest that a higher viscosity facilitates learned satiatio

Taste of a 24-h diet and its effect on subsequent food preferences and satiety

The objective of this study was to investigate the effect of taste of a 24-h diet on subsequent food preferences (food choice and intake of specific food categories) and satiety. We used a crossover design, consisting of a 24-h fully controlled dietary intervention, during which 39 healthy subjects consumed diets that were predominantly sweet tasting, savory tasting, or a mixture. The diets were similar in energy content, macronutrient composition, and number of different products used. Following the intervention an ad libitum lunch buffet was offered the next day, consisting of food items differing in taste (sweet/savory) and protein content (low/high) and intake was measured. The results showed that the taste of the diet significantly altered preference for food according to their taste properties (p <0.0001); after the savory diet, intake of sweet foods was higher than of savory foods. After the sweet diet, savory foods tended to be preferred (p = 0.07). No interaction was seen between the taste of the diet and food preference according to their protein content (p = 0.67). No differences in total energy intake (kJ) at the ad libitum lunch buffet were observed (p = 0.58). It appears that in healthy subjects, taste of a 24-h diet largely affects subsequent food preferences in terms of sensory appetite, whereby savory taste exerts the strongest modulating effect. Taste of a 24-h diet has no effect on macronutrient appetite