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 arti®cial) 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 signi®cantly 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.Visual analogue scales: Electronic appetite rating systems: Appetite: Hunger A speci®c advantage of studying the behaviour of human subjects (relative to animals) is that human subjects can be asked a number of questions relating to their motivation, sensations and attitudes. Psychologists and clinicians have long used subjective feelings of bodily sensations or functions to help in research investigations and patient management. Such assessments have been carried out in diverse conditions to examine a variety of`functions': quality of life (Hunt et al. 1981), pain (Ohnhaus & Alder, 1975;Downie et al. 1978), sex, libido, depression, anxiety (Keys et al. 1950, nausea and appetite (Hill & Blundell, 1982). Freyd (1923) has pointed out that such ratings are the only practical equivalents of objective measurements for many types of psychological phenomena, especially introspective or verbally reported data.Attempting to understand the role of food and ...

Objective: To identify and characterize the individual variability in compensation for exercise-induced changes in energy expenditure (EE). Design: Twelve-week exercise intervention. Subjects: Thirty-five overweight and obese sedentary men and women (body mass index, 31.874.1 kg m À2 ; age, 39.6711.0 years) were prescribed exercise five times per week for 12 weeks under supervised conditions. Measurements: Body weight, body composition, resting metabolic rate (RMR), total daily energy intake (EI) and subjective appetite sensations were measured at weeks 0 and 12. Results: When all subjects' data were pooled, the mean reduction in body weight (3.773.6 kg) was significant (Po0.0001) and as predicted, which suggested no compensation for the increase in EE. However, further examination revealed a large individual variability in weight change (À14.7 to þ 1.7 kg). Subjects were identified as compensators (C) or noncompensators (NC) based on their actual weight loss (mean NC ¼ 6.373.2 kg and C ¼ 1.57 2.5 kg) relative to their predicted weight loss. C and NC were characterized by their different metabolic and behavioural compensatory responses. Moderate changes in RMR occurred in C (À69.27268.7 kcal day À1 ) and NC (14.27242.7 kcal day À1 ). EI and average daily subjective hunger increased by 268.27455.4 kcal day À1 and 6.9711.4 mm day À1 in C, whereas EI decreased by 1307485 kcal day À1 and there was no change in subjective appetite (0.479.6 mm day À1 ) in NC. Conclusion: These results demonstrate that expressing the exercise-induced change in body weight as a group mean conceals the large inter-individual variability in body weight and compensatory responses. Individuals who experience a lower than predicted weight loss are compensating for the increase in EE.

The obesity epidemic is a global trend and is of particular concern in children. Recent reports have highlighted the severity of obesity in children by suggesting: "today's generation of children will be the first for over a century for whom life expectancy falls." This review assesses the evidence that identifies the important role of physical activity in the growth, development and physical health of young people, owing to its numerous physical and psychological health benefits. Key issues, such as "does a sedentary lifestyle automatically lead to obesity" and "are levels of physical activity in today's children less than physical activity levels in children from previous generations?", are also discussed.Today's environment enforces an inactive lifestyle that is likely to contribute to a positive energy balance and childhood obesity. Whether a child or adolescent, the evidence is conclusive that physical activity is conducive to a healthy lifestyle and prevention of disease. Habitual physical activity established during the early years may provide the greatest likelihood of impact on mortality and longevity. It is evident that environmental factors need to change if physical activity strategies are to have a significant impact on increasing habitual physical activity levels in children and adolescents. There is also a need for more evidence-based physical activity guidelines for children of all ages. Efforts should be concentrated on facilitating an active lifestyle for children in an attempt to put a stop to the increasing prevalence of obese children.

Over the past 30 years, the understanding of eating behaviour has been dominated by the concept of dietary restraint. However, the development of the Three Factor Eating Questionnaire (TFEQ), introduced two other factors; Disinhibition and Hunger, which have not received as much recognition in the literature. The objective of this review is to explore the relationship of the Disinhibition factor to weight regulation, food choice and eating disorders, and to consider its etiology. The review indicates that Disinhibition is an important eating behaviour trait. It is not only associated with a higher BMI and obesity, but also with mediating variables, such as less healthful food choices, which contribute to overweight/obesity and poorer health. Disinhibition is also implicated in eating disorders and contributes to eating disorder severity. It has been demonstrated that Disinhibition is predictive of poorer success at weight loss, and of weight regain during weight loss regimes and is associated with lower self-esteem, low physical activity and poor psychological health. Disinhibition therefore, emerges as an important and dynamic trait, with influences that go beyond eating behaviour and incorporate other behaviours which contribute to weight regulation and obesity. The characteristics of Disinhibition itself therefore reflect many components representative of a thrifty type of physiology. We propose that the trait of Disinhibition could be more appropriately renamed as 'Opportunistic Eating' or 'Thrifty Behaviour'.