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R J Stubbs

Publications and source records attributed to R J Stubbs.

At least 19 recordsLinked to original sources
PubMed2006

Energy density and weight of food effect short-term caloric compensation in men.

OBJECTIVE: The purpose of the study was to examine the effect of energy density and food weight (volume) on subsequent intake. DESIGN: Sixteen lean men were each studied four times during a 2-d protocol at the Rowett's Human Nutrition Unit. On day 1, subjects were fed a mandatory diet at 1.6 x resting metabolic rate (RMR). On day 2, during the mandatory morning period (08.30-12.30) subjects consumed a fixed breakfast (08.30) plus a snack (10.30) in one of four treatments [with values in weight (kg), ED (kJ/100g), Energy (MJ)]: (i) zero intake, 0:0:0 (ii) low energy density (LED), 0.615: 400: 2.46; (iii) high energy density (HED), 0.615: 800: 4.92; (iv) 2 x LED, 1.225: 400: 4.91. From 12.30, throughout the remainder of the day, subjects had ad libitum access to 15 high-protein, 15 high-fat and 15 high-carbohydrate foods. Motivation to eat was tracked hourly using 100 mm line scales. RESULTS: ANOVA showed subjects were hungrier after the zero and LED treatments in the mandatory period (p<0.001). Lunch time EI was 5.0, 3.1, 4.2 and 3.2 MJ on the zero, HED, LED and 2 x LED treatments, respectively (p<0.001). Total ad libitum EI was 11.7, 9.6, 10.3 and 9.5 MJ/d, respectively (p=0.033). Total ad libitum plus mandatory intakes amounted to 11.7, 14.5, 12.6 and 14.4 MJ/d, respectively (p=0.001). Corresponding food intakes were 2.18, 2.39, 2.51 and 3.06 kg/d, respectively (p<0.001). CONCLUSIONS: The present study showed that subjects respond to both the amount of food eaten in the morning and to the energy density of those foods. However, compensation was only partial and short-term. Subjects only compensated EI by approximately 40% and that compensation only occurred at the next meal.

Adult↗
PubMed2006

The evaluation of an electronic visual analogue scale system for appetite and mood.

Our objective was to evaluate a new electronic visual analogue scale (VAS) system for logging subjective motivation to eat ratings. In total, 10 men and 10 women completed both electronic and traditional pen and paper versions of the questionnaire every hour of the waking day. Subjects consumed a standard medium-fat diet, which was fixed at 1.6.BMR. Correlation coefficients for scores obtained by both methods were significant for all questions, with R(2) values ranging from 67 to 87%. However, Bland and Altman plots and paired t-tests identified significant bias between the two methods for five of the nine individual questions. These were questions that tended to be scored more towards the ends of the VAS. The new electronic VAS produces comparable, but not interchangeable, results to the traditional pen and paper method in the study of appetite and mood, while offering advantages of improved reliability in data collection.

Adult↗
PubMed2006

Control of energy balance in relation to energy intake and energy expenditure in animals and man: an ecological perspective.

In this paper, we consider the control of energy balance in animals and man. We argue that patterns of mammalian feeding have evolved to control energy balance in uncertain environments. It is, therefore, expected that, under sedentary conditions in which the diet is rich in nutrients and abundantly available, animals and man will overeat. This suggests that no physiological defects are needed to induce overweight and ultimately obesity in man. Several considerations arise from these observations. The time period over which energy balance is controlled is far longer than allowed by most experiments. Physiological models of energy balance control often treat excess energy intake as a defect of regulation; ecological models view the same behaviour as part of normal energy balance control in environments where resources are uncertain. We apply these considerations to common patterns of human and animal feeding. We believe that the ecological perspective gives a more accurate explanation for the functionality of excess fat and the need to defend nutrient balance and avoid gross imbalances, as well as explaining hyperphagia in the face of plenty. By emphasising the common features of energy balance control in different mammalian species, the importance of changes in behaviour to accommodate changes in the environment becomes apparent. This also opens up possibilities for the control of body weight and the treatment of obesity in man.

Animals↗
PubMed2005

Resistance and susceptibility to weight gain: individual variability in response to a high-fat diet.

An obesigenic environment is a potent force for promoting weight gain. However, not all people exposed to such an environment become obese; some remain lean. This means that some people are susceptible to weight gain (in a weight-promoting environment) and others are resistant. Identifying the characteristics of appetite control and food motivation in these two groups could throw light on the causes of weight gain and how this can be either treated or prevented. We have investigated the issue experimentally by identifying people who habitually consume a high-fat diet (greater than 43% fat energy). These individuals have been termed high-fat phenotypes. We have compared individuals, of the same age (mean=37 years old) and gender (male), who have gained weight (BMI=34) or who have remained lean (BMI=22). The susceptible individuals are characterised by a cluster of characteristics including a weak satiety response to fatty meals, a maintained preference for high-fat over low-energy foods in the post-ingestive satiety period, a strong hedonic attraction to palatable foods and to eating, and high scores on the TFEQ factors of Disinhibition and Hunger. The analysis of large databases suggests that this profile of factors contributes to an average daily positive energy balance from food of approximately 0.5 MJ. This profile of characteristics helps to define the symptomatology of a thrifty phenotype.

Appetite↗
PubMed2004

Energy density, diet composition and palatability: influences on overall food energy intake in humans.

This paper considers the role of energy density (ED), diet composition and palatability in the control of energy intake (EI) in humans through several related considerations: (i) the relationship between ED and diet composition, (ii) the relationship between ED, diet composition and EI, (iii) the relationship between palatability and EI, (iv) the relationship between ED, palatability and EI, (v) the importance of postingestive factors in influencing palatability in the longer term, (vi) the contribution of sensory and nutritional factors to dietary hyperphagia and (vii) the implications these considerations have for people living their normal lives in their natural environment. The main factors influencing ED are the fat and water content of foods. Energy density does elevate EI, especially in short-term studies where it can account for >40% of the variance in EI. In real life, ED accounts for only approximately 7% of the variance in EI. This is because the determinants of EI are multifactorial and also because the short-term effects of ED on EI do not translate into the longer term. We argue that part of the longer term amelioration of short-term effects of ED on EI is due to learned compensation, based on the postingestive consequences of consuming familiar food that differ in ED. More energy-dense foods tend to be more palatable but we learn to consume them in smaller portion sizes. In the longer term, the perceived palatability of a food is strongly influenced by the postingestive consequences of eating it. This effect can override sensory factors alone. This implies that nutrient mimetics, if used continuously, would not be as efficacious as initially supposed and that their ad hoc use may undermine the stability of learned appetites and satieties for foods with different EDs and contribute to the poor weight control capability exhibited by consumers at large.

Diet↗
PubMed2004

Rate and extent of compensatory changes in energy intake and expenditure in response to altered exercise and diet composition in humans.

We assessed the effect of no exercise (Nex; control) and high exercise level (Hex; approximately 4 MJ/day) and two dietary manipulations [a high-fat diet (HF; 50% of energy, 700 kJ/100 g) and low-fat diet (LF; 20% of energy, 300 kJ/100 g)] on compensatory changes in energy intake (EI) and energy expenditure (EE) over 7-day periods. Eight lean men were each studied four times in a 2 x 2 randomized design. EI was directly quantified by weight of food consumed. EE was assessed by heart rate (HR) monitoring. Body weight was measured daily. Mean daily EE was 17.6 and 11.5 MJ/day (P < 0.001) on the pooled Hex and Nex treatments, respectively. EI was higher on HF diets (13.4 MJ/day pooled) compared with the LF diets (9.0 MJ/day). Regression analysis showed that these energy imbalances induced significant compensatory changes in EB over time of approximately 0.3-0.4 MJ/day (P < 0.05). These were due to changes in both EI and EE in the opposite direction to the perturbation in energy balance. These changes were significant, small but persistent, amounting to approximately 0.2 and approximately 0.35 MJ/day for EI and EE, respectively.

Adaptation, Physiological↗
PubMed2003

Cross talk between physical activity and appetite control: does physical activity stimulate appetite?

Physical activity has the potential to modulate appetite control by improving the sensitivity of the physiological satiety signalling system, by adjusting macronutrient preferences or food choices and by altering the hedonic response to food. There is evidence for all these actions. Concerning the impact of physical activity on energy balance, there exists a belief that physical activity drives up hunger and increases food intake, thereby rendering it futile as a method of weight control. There is, however, no evidence for such an immediate or automatic effect. Short (1-2 d)-term and medium (7-16 d)-term studies demonstrate that men and women can tolerate substantial negative energy balances of < or = 4 MJ energy cost/d when performing physical activity programmes. Consequently, the immediate effect of taking up exercise is weight loss (although this outcome is sometimes difficult to assess due to changes in body composition or fluid compartmentalization). However, subsequently food intake begins to increase in order to provide compensation for about 30% of the energy expended in activity. This compensation (up to 16 d) is partial and incomplete. Moreover, subjects separate into compensators and non-compensators. The exact nature of these differences in compensation and whether it is actually reflective of non-compliance with protocols is yet to be determined. Some subjects (men and women) performing activity with a cost of < or = 4 MJ/d for 14 d, show no change in daily energy intake. Conversely, it can be demonstrated that when active individuals are forced into a sedentary routine food intake does not decrease to a lower level to match the reduced energy expenditure. Consequently, this situation creates a substantial positive energy balance accompanied by weight gain. The next stage is to further characterize the compensators and non-compensators, and to identify the mechanisms (physiological or behavioural) that are responsible for the rate of compensation and its limits.

Anorexia↗
PubMed2002

The effect of graded levels of exercise on energy intake and balance in free-living men, consuming their normal diet.

OBJECTIVE: To assess the effect of graded increases in exercised-induced energy expenditure (EE) on appetite, energy intake (EI), total daily EE and body weight in men living in their normal environment and consuming their usual diets. DESIGN: Within-subject, repeated measures design. Six men (mean (s.d.) age 31.0 (5.0) y; weight 75.1 (15.96) kg; height 1.79 (0.10) m; body mass index (BMI) 23.3(2.4) kg/m(2)), were each studied three times during a 9 day protocol, corresponding to prescriptions of no exercise, (control) (Nex; 0 MJ/day), medium exercise level (Mex; approximately 1.6 MJ/day) and high exercise level (Hex; approximately 3.2 MJ/day). On days 1-2 subjects were given a medium fat (MF) maintenance diet (1.6 x resting metabolic rate (RMR)). MEASUREMENTS: On days 3-9 subjects self-recorded dietary intake using a food diary and self-weighed intake. EE was assessed by continual heart rate monitoring, using the modified FLEX method. Subjects' HR (heart rate) was individually calibrated against submaximal VO(2) during incremental exercise tests at the beginning and end of each 9 day study period. Respiratory exchange was measured by indirect calorimetry. Subjects completed hourly hunger ratings during waking hours to record subjective sensations of hunger and appetite. Body weight was measured daily. RESULTS: EE amounted to 11.7, 12.9 and 16.8 MJ/day (F(2,10)=48.26; P<0.001 (s.e.d=0.55)) on the Nex, Mex and Hex treatments, respectively. The corresponding values for EI were 11.6, 11.8 and 11.8 MJ/day (F(2,10)=0.10; P=0.910 (s.e.d.=0.10)), respectively. There were no treatment effects on hunger, appetite or body weight, but there was evidence of weight loss on the Hex treatment. CONCLUSION: Increasing EE did not lead to compensation of EI over 7 days. However, total daily EE tended to decrease over time on the two exercise treatments. Lean men appear able to tolerate a considerable negative energy balance, induced by exercise, over 7 days without invoking compensatory increases in EI.

Adult↗
PubMed2002

The effect of graded levels of exercise on energy intake and balance in free-living women.

AIM: We assessed the effect of graded increases in exercised-induced energy expenditure (EE) on appetite, daily energy intake (EI), total daily EE and body weight in six lean women using a within-subject, repeated measures design. METHOD: Subjects were each studied three times during 7 day treatments, corresponding to no-exercise (control; Nex; 0 MJ/day), medium exercise level (Mex; approximately 1.9 MJ/day) and high exercise level (Hex; approximately 3.4 MJ/day), with 2 day maintenance beforehand. Subjects self-weighed ad libitum food intake. EE was assessed by continual heart rate monitoring. During waking hours subjects recorded hourly sensations of hunger and appetite. RESULTS: EE amounted to 9.2, 11.0 and 12.1 MJ/day (F (2, 10)=5.67; P=0.023 (s.e.d.=0.87)) on the Nex, Mex and Hex treatments, respectively. The corresponding values for EI were 8.9, 9.2 and 10.0 MJ/day (F (2, 10)=4.80; P=0.035 (s.e.d.=0.36)). There were very weak treatment effects on hunger. Weight loss was significantly different from zero on the Mex and Hex treatments. CONCLUSION: Markedly increasing EE through exercise produced significant but partial compensations in EI ( approximately 33% of EE due to exercise). Accurate adjustments of El to acute increases in EE are likely to take weeks rather than days.

Adult↗
PubMed2002

Effect of an acute fast on energy compensation and feeding behaviour in lean men and women.

AIM: Humans appear to defend against energy deficit to a greater extent than energy surplus. Severe dietary energy restriction resulting in 5-30% weight loss often leads to hyperphagia and weight regain in lean subjects. However, the period of time over which fasting is often endured in Western society are far shorter, approximately 1-2 days. This study examined how a 36 h fast effected the subsequent day's energy and nutrient intake in a group of 24 healthy, lean men and women. METHOD: Subjects underwent two 2 day treatments, termed 'fast' and 'maintenance'. During the 'fast' treatment, subjects were fed a maintenance diet on the day prior to the fast (day -1) to prevent overeating. They then consumed non-energy drinks only, from 20:00 h on day -1 to 08:00 h on day 2 (ad libitum feeding day), thus fasting for 36 h. On the 'maintenance' protocol, subjects received a maintenance diet throughout day 1. Throughout day 2 they had ad libitum access to a range of familiar foods, which were the same for both treatments. Body weight, blood glucose and respiratory quotient were used as compliance checks. Hunger was monitored on day's -1, 1 and 2 for the fast treatment only. RESULTS: On day 2, average energy intake was 10.2 vs 12.2 MJ/day (s.e.d. 1.0) on the post-maintenance and post-fast periods, respectively (P=0.049). Subjects altered feeding behaviour, in response to the fast, only at breakfast time, selecting a higher-fat meal (P<0.005). Compared to day -1, motivation to eat was elevated during the fast (P<0.05). This continued until breakfast was consumed during the re-feeding period (day 2), when values then returned to baseline. CONCLUSION: These data suggest that a 36 h fast, which generated a negative energy balance of approximately 12 MJ, did not induce a powerful, unconditioned stimulus to compensate on the subsequent day.

Adult↗
PubMed2001

The use of selective adsorbents in capillary electrophoresis-mass spectrometry for analyte preconcentration and microreactions: a powerful three-dimensional tool for multiple chemical and biological applications.

Much attention has recently been directed to the development and application of online sample preconcentration and microreactions in capillary electrophoresis using selective adsorbents based on chemical or biological specificity. The basic principle involves two interacting chemical or biological systems with high selectivity and affinity for each other. These molecular interactions in nature usually involve noncovalent and reversible chemical processes. Properly bound to a solid support, an "affinity ligand" can selectively adsorb a "target analyte" found in a simple or complex mixture at a wide range of concentrations. As a result, the isolated analyte is enriched and highly purified. When this affinity technique, allowing noncovalent chemical interactions and biochemical reactions to occur, is coupled on-line to high-resolution capillary electrophoresis and mass spectrometry, a powerful tool of chemical and biological information is created. This paper describes the concept of biological recognition and affinity interaction on-line with high-resolution separation, the fabrication of an "analyte concentrator-microreactor", optimization conditions of adsorption and desorption, the coupling to mass spectrometry, and various applications of clinical and pharmaceutical interest.

Absorption↗
PubMed2001

Description and evaluation of a Newton-based electronic appetite rating system for temporal tracking of appetite in human subjects.

This study assessed the reliability and validity of a palm-top-based electronic appetite rating system (EARS) in relation to the traditional paper and pen method. Twenty healthy subjects [10 male (M) and 10 female (F)] - mean age M=31 years (S.D.=8), F=27 years (S.D.=5); mean BMI M=24 (S.D.=2), F=21 (S.D.=5) - participated in a 4-day protocol. Measurements were made on days 1 and 4. Subjects were given paper and an EARS to log hourly subjective motivation to eat during waking hours. Food intake and meal times were fixed. Subjects were given a maintenance diet (comprising 40% fat, 47% carbohydrate and 13% protein by energy) calculated at 1.6xResting Metabolic Rate (RMR), as three isoenergetic meals. Bland and Altman's test for bias between two measurement techniques found significant differences between EARS and paper and pen for two of eight responses (hunger and fullness). Regression analysis confirmed that there were no day, sex or order effects between ratings obtained using either technique. For 15 subjects, there was no significant difference between results, with a linear relationship between the two methods that explained most of the variance (r(2) ranged from 62.6 to 98.6). The slope for all subjects was less than 1, which was partly explained by a tendency for bias at the extreme end of results on the EARS technique. These data suggest that the EARS is a useful and reliable technique for real-time data collection in appetite research but that it should not be used interchangeably with paper and pen techniques.

Adult↗
PubMed2001

Effect of altering the variety of sensorially distinct foods, of the same macronutrient content, on food intake and body weight in men.

OBJECTIVE: To examine the effect of increasing the variety of sensorially distinct but nutritionally identical foods on appetite, food intake and body weight, over 7 days, in men. DESIGN: Six younger, lean men (mean (s.d.) age 27.0 (2.9) y; weight 74.7 (3.9) kg; height 1.78 (0.03) m; body mass index (BMI) 23.6 (1.1) kg/m2) and six older, overweight men (mean (s.d.) age 39.7 (2.9) y; weight 89.2 (4.4) kg; height 1.78 (0.04) m; BMI 28.1 (0.5) kg/m2) were each studied three times during a 9 day protocol, whilst resident in the Human Nutrition Unit. On days 1-2, subjects consumed a medium fat (MF) maintenance diet (40% fat, 13% protein and 47% carbohydrate by energy) calculated at 1.6 x resting metabolic rate (RMR). On days 3-9 subjects had ad libitum access to MF foods (550 kJ/100 g) with every item the same macronutrient composition and energy density. Subjects had continuous ad libitum access to 5, 10 or 15 food items per day on the low-variety (LV), medium-variety (MV) and high-variety (HV) treatments, respectively. The order of treatments was randomized across subjects. Subjective hunger was tracked hourly during waking hours using visual analogue scales (VAS). Body weight (as a proxy of changes in energy balance) was measured before eating and after voiding, each morning. RESULTS: Food and energy intake of the 12 men increased as the variety of foods increased, giving mean energy intakes of 10.13, 11.00 and 11.89 MJ/day on the LV, MV and HV treatments, respectively (F(2,20) = 10.32; P < 0.001). This effect was ascribable almost entirely to the lean men. Energy intake amounted to 1.57, 1.76 and 1.97 x RMR in the lean men and 1.33, 1.40 and 1.45 x RMR, for the overweight men on the LV, MV and HV diets, respectively. Weight changes amounted to -0.16, -0.28 and + 0.43 kg (lean) -1.03 and -1.52 kg and -0.66 kg (overweight), on the LV, MV and HV diets, respectively. The overweight men may have constrained their energy intake relative to expected requirements. This may have been due to a congnitive effect or an age effect. There was no significant group or diet effect on subjectively rated hunger. CONCLUSIONS: These data suggest that increasing the variety of sensorially distinct foods that are virtually identical in composition can increase food and energy intake and in the short to medium term can alter energy balance.

Adult↗
PubMed2001

How covert are covertly manipulated diets?

OBJECTIVE: To quantitatively assess subjects' ability to detect hedonic (palatability), sensory and nutritional differences between covertly manipulated high-fat (HF) and low-fat (LF) diets. SUBJECTS AND DIETS: This study examined the response of 16 subjects (eight men, eight women) to 20 LF and 20 HF versions of manipulated foods. Average percentage protein:fat:carbohydrate (by energy) and energy density (ED) of the two diets were 13:25:62, 371 kJ/100 g and 13:50:37, 672 kJ/100 g, respectively. PROTOCOL: Subjects were asked to simultaneously assess the HF and LF versions of each food in terms of (i) subjective pleasantness of each food, (ii) perceived differences in appearance, smell, taste and texture of the foods, and (iii) for each sample to assess whether it was high or low in energy, protein, carbohydrate, fat, fibre, sugar and salt. ANALYSIS: Perceived pleasantness of HF and LF versions of the foods was compared by analysis of variance. Comparisons used chi-squared tests of independence to assess departure from the null hypothesis of no perceived difference in remaining parameters (ii-iii). RESULTS: On average, subjects exhibited no significant preference for LF or HF versions of the foods (no difference 15 foods, three HF foods more pleasant, two LF foods more pleasant (P<0.03)). On average there were no general differences in comparison of sensory attributes that were consistently ascribable to the LF or HF foods, although there were numerous significant differences for individual foods. Subjects appeared unable to distinguish the HF foods as being HF (66% of estimates) and guessed correctly 33% of the time. They were better able to categorize the LF foods correctly (53% correct). On aggregate 43% of HF and LF foods were correctly identified. Subjects appeared able to detect sensory differences between foods but not to relate them to energy or nutrient content of these foods. CONCLUSIONS: These data suggest that subjects are on average not able to perceive large differences in the fat content of diets manipulated in this manner. In general the assumption that the manipulation of such foods is covert appears to hold, but subjects were far better at correctly identifying certain food types (dairy-based) over others.

Adult↗
PubMed2001

The effect of ingesting olestra-based foods on feeding behavior and energy balance in humans.

This article reviews currently published works on the effects of olestra on appetite and energy intake (EI) in humans. To date 24 studies have examined the impact of olestra-containing foods on aspects of feeding behavior, which are published in 20 reports. The general response of human subjects to olestra-based decreases in dietary energy density (ED) is either poor caloric compensation or partial (nonmacronutrient specific) increases in EI. Averaging the degree of energy compensation across 22 studies gives a value of 27% (nonweighted mean). In studies where compensation occurred, fat intake but not EI was reduced. These effects appear to occur in both lean and obese, men and women and under a variety of conditions ranging from the laboratory to real life. However, all but two of these studies were short term. One study suggests that in subjects to whom weight loss is desirable these deficits can persist for up to 3 months. Subjects with no wish to lose weight may compensate better over longer periods. In another 3-month study, ingestion of olestra-based foods did not induce energy deficits but limited the significant weight gain seen on a full-fat control. The longer term effects of olestra on body weight requires further investigation. There is evidence that restrained eaters tend to eat slightly more of olestra-based foods if they know that they are reduced in fat and energy. This is probably a general response to low-fat foods rather than to olestra per se. The fact that olestra-based foods have the potential to provide the sensory qualities of real fat suggests that these foods may be particularly effective in habitual high-fat consumers with a sensory preference for dietary fat.

Adult↗
PubMed2001

Carbohydrates, appetite and feeding behavior in humans.

The view of carbohydrates in relation to obesity has changed over the past few decades from being conducive to overconsumption and weight gain to being protective. This article reviews the mechanisms by which carbohydrate is purported to protect against weight gain. Although carbohydrate is metabolized and stored in the body less efficiently than fat, when de novo lipogenesis is invoked on very high carbohydrate diets, the beneficial effect on energy balance is likely to be minimal when typical high fat Western diets are consumed. However, it has been suggested that high carbohydrate foods may influence energy balance by reducing food intake through greater satiety effects, reducing energy density and displacing fat from the diet-the fat-sugar seesaw effect. To date, there seem to be few differences between sugars and starches on satiety and energy intake, but few studies have examined this. Some reduced-fat, and, therefore, higher carbohydrate, foods are highly energy dense. High carbohydrate foods do not necessarily have a low energy density. Evidence from recent studies suggests that adding carbohydrate, and especially sugar, to the diet neither displaces fat from the diet nor protects against elevated energy intake. Although it is easier to overeat on high fat than low fat foods, simply replacing fat with carbohydrate in the diet may not be as protective against overconsumption as the energy density or fat-sugar seesaw arguments suggest.

Appetite↗
PubMed2000

The use of visual analogue scales to assess motivation to eat in human subjects: a review of their reliability and validity with an evaluation of new hand-held computerized systems for temporal tracking of appetite ratings.

This present paper reviews the reliability and validity of visual analogue scales (VAS) in terms of (1) their ability to predict feeding behaviour, (2) their sensitivity to experimental manipulations, and (3) their reproducibility. VAS correlate with, but do not reliably predict, energy intake to the extent that they could be used as a proxy of energy intake. They do predict meal initiation in subjects eating their normal diets in their normal environment. Under laboratory conditions, subjectively rated motivation to eat using VAS is sensitive to experimental manipulations and has been found to be reproducible in relation to those experimental regimens. Other work has found them not to be reproducible in relation to repeated protocols. On balance, it would appear, in as much as it is possible to quantify, that VAS exhibit a good degree of within-subject reliability and validity in that they predict with reasonable certainty, meal initiation and amount eaten, and are sensitive to experimental manipulations. This reliability and validity appears more pronounced under the controlled (but more artificial) conditions of the laboratory where the signal:noise ratio in experiments appears to be elevated relative to real life. It appears that VAS are best used in within-subject, repeated-measures designs where the effect of different treatments can be compared under similar circumstances. They are best used in conjunction with other measures (e.g. feeding behaviour, changes in plasma metabolites) rather than as proxies for these variables. New hand-held electronic appetite rating systems (EARS) have been developed to increase reliability of data capture and decrease investigator workload. Recent studies have compared these with traditional pen and paper (P&P) VAS. The EARS have been found to be sensitive to experimental manipulations and reproducible relative to P&P. However, subjects appear to exhibit a significantly more constrained use of the scale when using the EARS relative to the P&P. For this reason it is recommended that the two techniques are not used interchangeably.

Appetite↗