Meat intake in Britain in relation to other dietary components and to demographic and risk factor variables: analyses based on the National Diet and Nutrition Survey of 2000/2001.

BACKGROUND: Red and processed meat intakes have been positively associated with the risk of several major chronic diseases. Understanding population intakes is important when formulating dietary recommendations. The present study investigated the dispersion of intakes of red and processed meat and associations with dietary, socio-demographic and risk factors. METHODS: The present study comprised a secondary analysis of the British National Diet and Nutrition Survey 2000/1, including 7-day dietary records, from 766 male and 958 female respondents aged 19-64 years. Composite dishes were disaggregated into primary ingredients. Self-reported vegetarians (V) were grouped into one stratum and other respondents were stratified into five groups (F1-F5) according to energy-adjusted red plus processed meat (RPM) intake, to give six strata. 7-day RPM intakes were adjusted to estimate 'usual' habitual intakes, using ratios of between-person to total variance in daily intakes. RESULTS: Mean recorded intakes of red, processed, white and total meat were 48, 41, 40 and 129 g day(-1) , respectively, in males and 30, 22, 30 and 82 g day(-1) in females. Estimated habitual intakes of RPM standardised to sex-specific energy intakes across the six strata were: 12 (V), 56, 76, 90, 105 and 137 g day(-1) in males and 5 (V), 34, 46, 55, 65 and 88 g day(-1) in females. Lower RPM consumers tended to be of higher social class and educational level and to have more favourable levels of some risk factors. CONCLUSIONS: Mean intakes of red, processed and white meat were of similar magnitude. Habitual intakes of RPM showed wide dispersion with one-quarter of males < 55 g day(-1) and one-quarter of females < 27 g day(-1) . Lowering overall RPM consumption could be achieved by seeking greater reductions among current high consumers.

Developing a methodology for assigning glycaemic index values to foods consumed across Europe.

There is growing evidence that the glycaemic index (GI) of the diet is important with respect to body weight and metabolic disease risk. However, research is limited by the paucity of GI values for commonly consumed carbohydrate-rich foods in European countries. A new methodology has been developed for consistent assignment of GI values to foods across five European databases used in the Diogenes intervention study. GI values were assigned according to five decreasing levels of confidence (1) Measured values for specific foods; (2) Published values from published sources; (3) Equivalent values where published values for similar foods existed; (4) Estimated values assigned as one of three values representing low/medium/high GI ranges and (5) Nominal values assigned as 70, where no other value could be assigned with sufficient confidence. GI values were assigned to 5105 foods. In food records collected at baseline, the contribution to carbohydrate intake of foods assigned levels 1-2 ranged from 16% to 43% depending on country, and this increased to 53-81% including level 3 foods. The degree of confidence to assigned GI values differed across Europe. This standardized approach of assigning GI values will be made available to other researchers to facilitate further investigation into the effects of dietary GI on health.

Determination of the glycaemic index of various staple carbohydrate-rich foods in the UK diet.

OBJECTIVE: To determine the glycaemic index (GI) of various staple carbohydrate-rich foods in the UK diet, and to consider the factors influencing the GI of foods. DESIGN: Subjects were served with 25 or 50 g portions of glucose on three occasions, followed by a selection of test foods providing an equal amount of available carbohydrate, in random order. Each test food was consumed by 10 subjects. Capillary blood glucose levels were measured in the fasted state and over the 120 min following commencement of consumption of the foods. SETTING: The study was carried out in a research institute (MRC Human Nutrition Research, Cambridge, UK). SUBJECTS: Forty-two healthy adult volunteers were studied. METHODS: The GI values of 33 foods were measured according to the WHO/FAO recommended methodology. These foods included various breads, breakfast cereals, pasta, rice and potatoes, all of which were commercially available in the UK. CONCLUSIONS: The results illustrate a number of factors which are important in influencing the GI of a food, highlighting the importance of measuring the GI of a food, rather than assuming a previously published value for a similar food. This is useful both to researchers analysing dietary surveys or planning intervention studies, and also to health professionals advising individuals on their diets.

No effect of a diet with a reduced glycaemic index on satiety, energy intake and body weight in overweight and obese women.

OBJECTIVE: To investigate whether a diet with a reduced glycaemic index (GI) has effects on appetite, energy intake, body weight and composition in overweight and obese female subjects. DESIGN: Randomized crossover intervention study including two consecutive 12-week periods. Lower or higher GI versions of key carbohydrate-rich foods (breads, breakfast cereals, rice and pasta/potatoes) were provided to subjects to be incorporated into habitual diets in ad libitum quantities. Foods intended as equivalents to each other were balanced in macronutrient composition, fibre content and energy density. SUBJECTS: Nineteen overweight and obese women, weight-stable, with moderate hyperinsulinaemia (age: 34-65 years, body mass index: 25-47 kg m(-2), fasting insulin: 49-156 pmol l(-1)). MEASUREMENTS: Dietary intake, body weight and composition after each 12-week intervention. Subjectively rated appetite and short-term ad libitum energy intake at a snack and lunch meal following fixed lower and higher GI test breakfasts (GI 52 vs 64) in a laboratory setting. RESULTS: Free-living diets differed in GI by 8.4 units (55.5 vs 63.9), with key foods providing 48% of carbohydrate intake during both periods. There were no differences in energy intake, body weight or body composition between treatments. On laboratory investigation days, there were no differences in subjective ratings of hunger or fullness, or in energy intake at the snack or lunch meal. CONCLUSION: This study provides no evidence to support an effect of a reduced GI diet on satiety, energy intake or body weight in overweight/obese women. Claims that the GI of the diet per se may have specific effects on body weight may therefore be misleading.