We studied four different techniques of preoxygenation in 20 healthy volunteers, by continuous analysis of respired gases. Three minutes of tidal breathing from a Magill breathing system or four vital capacity breaths from a non-rebreathing system were found to be equally effective, whereas four vital capacity breaths from a Magill breathing system were less effective. Maximal expiration before...

Two routes to overeating are discussed; they are both premised on people's strong motivation to avoid eating excessively and thereby avoid negative ascriptions associated with the overeatingloverweight stereotype. The first route to overeating involves infractions of restrictive intake norms: people who attempt to restrict their intake by implementing dietary rules often run afoul of disinhibit...

The portion-size effect (PSE) refers to the fact that people eat more when served larger portions. This effect is neither obvious nor artifactual. We examine the prevailing explanations (or underlying mechanisms) that have been offered for the PSE. The dominant candidate mechanism is "appropriateness"; that is, people accept the portion that they are served as being of an appropriate size and e...

The prevalence of overweight and obesity has increased. A strong environmental factor contributing to the obesity epidemic is food portion size. This review of studies into the effects of portion size on energy intake shows that increased food portion sizes lead to increased energy intake levels. Important mechanisms explaining why larger portions are attractive and lead to higher intake levels...

Portion size has increased considerably over the past few decades and one influencing factor is dishware size. Using mathematical models we investigated how dish size affects the potential energy available in a meal. Two types of plate filling - flat and conical - were modelled for a range of plate sizes and energy densities, then compared to recommended daily energy requirements from Australia...

People consistently over-eat when served a large compared with a small (appropriate) portion of food. However, the mechanism underlying this so-called portion size effect is not well understood. We argue that the process of anchoring and adjustment naturally describes this effect, such that the size of a presented portion works as an anchor that strongly influences consumption. The classical an...