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Background: e-epidemiology, a convenient and low-cost research method, is becoming increasingly popular. This study seeks to validate on-line self-reported heights and weights against objectively measured data in young adults. Methods: Young adults self-reported heights and weights in an on-line lifestyle survey. These were validated using two methods: (i) measurements by staff at the primary-care clinic and (ii) measurements by a researcher within two weeks of distribution of the survey. Analyses were conducted to determine differences between the self-reported and measured heights and weights and to identify characteristics associated with under- or over-reporting of these. Results: From a total of 23 010 young adults invited to the survey, 24% provided on-line data, mean age = 19.2 (SD 3.2) years, 43% male, 91% EU citizens. Both self-reported and measured data were available for 1446 individuals (547 men, 896 women and mean age 19.2 (SD2.6) years); 1278 validated using medical records, 168 by researcher measurements. Intra-class correlations between self-reported and measured parameters were weight (r = 0.99), height (r = 0.98), with acceptable levels of agreement between measured and self-reported weight, height and BMI using Bland & Altman analyses. Self-reported weight was underestimated uniformly across BMI categories, gender and ethnicity, by a mean -0.4 (SD 0.4) kg (P < 0.001). Height was accurately reported overall across BMI and gender: both self-reported and measured heights =1.72 (SD 0.01) m, P = 0.783. Discrepancies between methods caused misclassification of BMI category for 17 (1.8%) of participants. Conclusions: Engagement of young adults with on-line research is encouraging. On-line self-reporting provides acceptably reliable anthropometric data for young adults, with under-reporting of weight by just 0.4 kg.

This thesis describes the results of dietetic led weight management for weight loss in three different groups of subjects: overweight; overweight with angina; and those whose body weight was close to the healthy upper BMI of 25 kg/m2. It forms part of a growing literature examining moderate weight loss as a success outcome in weight management. The work in this thesis addresses an important general research question; whether the effect of modest weight loss per se on established risk factors for IHD was similar across a number of subject groups. The specific aims were to examine the effect of moderate weight loss on the established IHD risk factors, fibrinogen, factor VII activity, plasma and whole blood viscosity, PAI activity and t-PA antigen. The role of modest weight loss on the adrenal hormone DHEAS was also studied. The conclusion of this thesis is that modest weight loss, (around 4%) which can be achieved through well planned dietetic management, does produce important reductions in IHD risk. The weight loss achieved was similar in groups with BMI > 28 kg/m2, with or without IHD, but less in absolute terms in individuals with baseline weights near the top of the healthy (acceptable range). Reductions in factor VII activity and RCA were related to the amount of weight loss, but the reductions were not greater in those with higher baseline values and existing IHD. The falls in factor VII activity and RCA were accompanied by falls in other established IHD risk factors, plasma lipid concentrations and blood pressure.

This thesis describes the results of dietetic led weight management for weight loss in three different groups of subjects: overweight; overweight with angina; and those whose body weight was close to the healthy upper BMI of 25 kg/m2. It forms part of a growing literature examining moderate weight loss as a success outcome in weight management. The work in this thesis addresses an important general research question; whether the effect of modest weight loss per se on established risk factors for IHD was similar across a number of subject groups. The specific aims were to examine the effect of moderate weight loss on the established IHD risk factors, fibrinogen, factor VII activity, plasma and whole blood viscosity, PAI activity and t-PA antigen. The role of modest weight loss on the adrenal hormone DHEAS was also studied. The conclusion of this thesis is that modest weight loss, (around 4%) which can be achieved through well planned dietetic management, does produce important reductions in IHD risk. The weight loss achieved was similar in groups with BMI > 28 kg/m2, with or without IHD, but less in absolute terms in individuals with baseline weights near the top of the healthy (acceptable range). Reductions in factor VII activity and RCA were related to the amount of weight loss, but the reductions were not greater in those with higher baseline values and existing IHD. The falls in factor VII activity and RCA were accompanied by falls in other established IHD risk factors, plasma lipid concentrations and blood pressure.

This thesis describes the results of dietetic led weight management for weight loss in three different groups of subjects: overweight; overweight with angina; and those whose body weight was close to the healthy upper BMI of 25 kg/m2. It forms part of a growing literature examining moderate weight loss as a success outcome in weight management. The work in this thesis addresses an important general research question; whether the effect of modest weight loss per se on established risk factors for IHD was similar across a number of subject groups. The specific aims were to examine the effect of moderate weight loss on the established IHD risk factors, fibrinogen, factor VII activity, plasma and whole blood viscosity, PAI activity and t-PA antigen. The role of modest weight loss on the adrenal hormone DHEAS was also studied. The conclusion of this thesis is that modest weight loss, (around 4%) which can be achieved through well planned dietetic management, does produce important reductions in IHD risk. The weight loss achieved was similar in groups with BMI > 28 kg/m2, with or without IHD, but less in absolute terms in individuals with baseline weights near the top of the healthy (acceptable range). Reductions in factor VII activity and RCA were related to the amount of weight loss, but the reductions were not greater in those with higher baseline values and existing IHD. The falls in factor VII activity and RCA were accompanied by falls in other established IHD risk factors, plasma lipid concentrations and blood pressure.