It is often the case in dietary assessment that it is not practicable to weigh individual intakes of foods eaten. The aim of the work described was to estimate typical food portion weights for children of different ages. Using the data available from the British National Diet and Nutrition Surveys of children aged 1½–4½ years (1992–1993) and young people aged 4–18 years (1997), descriptive statistics were obtained, and predicted weights were calculated by linear, quadratic and exponential regression for each age group. Following comparison of energy and nutrient intakes calculated from actual (from an earlier weighed intake study) and estimated portion weights, the final list of typical portion sizes was based on median portion weights for the 1–3- and 4–6-year age groups, and age-adjusted means using linear regression for the 7–10-, 11–14- and 15–18-year age groups. The number of foods recorded by fifty or more children was 133 for each of the younger age groups (1–3 and 4–6 years) and seventy-five for each of the older age groups. The food portion weights covered all food groups. All portion sizes increased with age with the exception of milk in tea or coffee. The present study draws on a unique source of weighed data on food portions of a large sample of children that is unlikely to be repeated and therefore provides the best possible estimates of children's food portion sizes in the UK.

Leptin, originally identified as an anti-obesity hormone, also has an important role in the regulation of mood and emotion. The present study was designed to monitor effects of injected leptin on immobilization stress-induced anorexia, behavioral deficits, and plasma corticosterone secretion in rats. Exposure to 2 h immobilization stress decreased food intake and body weight in saline-injected animals. Animals exposed to open field, elevated plus maze, and light-dark transition tests the day following immobilization exhibited anxiety-like behavior. Leptin injected at doses of 0.1 and 0.5 mg/kg also decreased food intake and body weight in unstressed animals and elicited anxiolytic effects at dose of 0.5 mg/kg, monitored on the following day. Immobilization-induced decreases in food intake, body weight, as well as stress-induced behavioral deficits in the open field, elevated plus maze, and light-dark transition test were reversed by exogenous leptin in a dose-dependent (0.1-0.5 mg/kg) manner. Acute exposure to 2 h immobilization produced a fourfold rise in plasma levels of corticosterone. Animals injected with leptin at a dose of 0.1 mg/kg, but not at dose of 0.5 mg/kg, exhibited a marginal increase in plasma corticosterone. Immobilization-induced increases of plasma corticosterone were reversed by leptin injected at doses of 0.1 or 0.5 mg/kg. The data suggest that exogenous leptin can reduce stress perception, resulting in an inhibition of stress effects on the activity of hypothalamic-pituitary-adrenal axis and behavior. The reported pharmacological effects of leptin represent an innovative approach for the treatment of stress-related disorders.

No abstract

No abstract