Acne is prevalent amongst youth in Hong Kong and has considerable psychological effects. The application of a TCM approach led to the detection of significant associations between diet and the occurence of acne. TCM-syndrome-tailored dietary manipulation was effective in reducing the clinical severity of acne for patients with imbalance of chong-ren subtype. (Abstract shortened by UMI.) / In (1), 1068 Chinese subjects were sampled from the general health evaluation and eight governmental secondary schools in Hong Kong were assessed for their clinical severity of acne. Over 93% of the subjects had a certain degree of acne and the prevalence of clinical acne was of 40.4% and coexisted with a high frequency of acne disability. Assessment of the clinical severity of acne did not correlate strongly with the effect on QOL (gammas= 0.445, P < 0.001). Multivariate logistic regression showed that female gender (P = 0.002), higher GAGS score (P < 0.001), higher perceived stress (P = 0.01) and willingness to pay Hong Kong $15,000 for a hypothetical permanent cure (P = 0.03) were positive predictors for acne disability. / In (2), 322 university entrants completed a dietary questionnaire capturing 11 categories of food intake and were examined for body constitutions of yin-predominance or yang-predominance with a published TCM diagnostic assessment procedure/method. There were 155 (48.1%) participants in the yin-predominant group and 167 (51.9%) in the yang-predominant group. No association of diet and acne was found when the participants were considered as a whole group. In yin-predominant group, intake of foods from street stalls (P = 0.04) was significantly associated with a lower likelihood of acne occurence. In yang-PG, the intake of desserts (P = 0.04) and fresh fruit juices (P = 0.02) was significantly associated with a higher likelihood of acne occurence, whereas the intake of dairy and soy products (P = 0.04) was significantly associated with a lower likelihood of acne occurence. / In (3), 233 students with clinical acne as assessed by GAGS were diagnosed for his or her TCM syndrome subtype, namely wind-heat subtype, damp-heat subtype, stagnant blood or phlegm subtype, and imbalance of chong-ren subtype. They were then randomly assigned to either intervention group (IG) or control group (CG). There were respectively 60 students belonged to each of the wind-heat, damp-heat, and stagnant blood or phelgm subtypes, and 53 students belonged to imbalanced of chong-ren subtype. With the use of a computer generated randomisation list using blocks of six, 30 (50%) students were assigned to either IG or CG for wind-heat, damp-heat, and stagnant blood or phelgm subtypes accordingly, whilst 26 (49%) and 27 (51%) students were assigned to either IG or CG for imbalance of chongren subtype. TCM-syndrome-tailored diet advice plus standard medical advice were given to IG whilst standard medical advice alone was given to CG over 12-week study period. The primary analysis was to compare the percentage change of GAGS from baseline to 12 weeks between the groups using univariate analysis for each TCM syndrome, controlling for the variation in the dependent variables due to gender, age, BMI, schools, physical exercise, and female contraceptive use. Within the imbalance of chong-ren subtype, there was a significant reduction of acne severity in IG compared with that in CG (-11.8% vs 2.1%; p=0.046), after adjusting for gender, age, body mass index, schools, physical exercise, and female contraceptive use. In the other three subtypes, there were no significant differences of acne severity between IG and CG / This research was composed of three major parts: (1) a cross-sectional study investigating the prevalence of acne and the acne disability amongst adolescents and young adults from August 2006 to March 2008 in Hong Kong; (2) a cross sectional study investigate the diet-acne connection from a traditional Chinese medicine (TCM) perspective performed amongst young adults in August 2006; and (3) a randomised controlled trial on the effectivenss of TCM-syndrome-tailored dietary advice for adolescents implemented between November 2007 and March 2008 in Hong Kong. / Law, Pui Man. / Adviser: Albert Lee. / Source: Dissertation Abstracts International, Volume: 72-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 140-154). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese; appendix 2-3 in Chinese.