No abstract

OBJECTIVE: The therapeutic effectiveness of diet, exercise, and diet plus exercise for weight loss in obesity was determined. DATA SOURCES: All human research reported in English, published in peer-reviewed scienti®c journals within the past 25 y was reviewed. STUDY SELECTION: Acceptance criteria (n 493 from b 700 studies) were that a therapeutic intervention of diet, exercise or diet plus exercise was employed, speci®cally for weight reduction in obese adult humans and that weight change was reported numerically. Only aerobic exercise studies were included, while drug, hormone and surgical treatments were excluded. DATA EXTRACTION: All data were extracted by the same investigator from the original research report. Except for gender and program type, all extracted data were numerical. DATA SYNTHESIS: ANOVA, with a Newman±Keuls post hoc test, was used to determine differences among programs (P`0.05). One analysis was performed on the group mean data and one based on effect sizes. Analyses were repeated using initial body weight, initial percent body fat and program length, as covariates. RESULTS: Primarily, subjects aged 40 y have been studied (39.5 AE 0.4 y, mean AE s.e.m.) who are only moderately obese (92.7 AE 0.9 kg, 33.2 AE 0.5 body mass index (BMI), 33.4 AE 0.7% body fat); for short durations (15.6 AE 0.6 weeks). Exercise studies were of a shorter duration, used younger subjects who weighed less, had lower BMI and percentage body fat values, than diet or diet plus exercise studies. Despite these differences, weight lost through diet, exercise and diet plus exercise was 10.7 AE 0.5, 2.9 AE 0.4* and 11.0 AE 0.6 kg, respectively. However, at one-year follow-up, diet plus exercise tended to be the superior program. Effect size and covariate analyses revealed similar program differences. CONCLUSION: Weight loss research over the past 25 y has been very narrowly focused on a middle age population that is only moderately obese, while the interventions lasted for only short periods of time. The data shows, however, that a 15-week diet or diet plus exercise program, produces a weight loss of about 11 kg, with a 6.6 AE 0.5 and 8.6 AE 0.8 kg maintained loss after one year, respectively.

The authors examined the relation between age at first vaginal intercourse and a positive nucleic acid amplification test for sexually transmitted infection (STI). A nationally representative sample of 9,844 respondents aged 18-26 years was tested for chlamydial infection, gonorrhea, and trichomoniasis in wave 3 (2001)(2002) of the National Longitudinal Study of Adolescent Health. The authors used multiple logistic regression to assess the relation between age at first sexual intercourse and these STIs and to examine variation by current age, sex, race, and ethnicity. Younger ages at first intercourse were associated with higher odds of STI in comparison with older ages, but the effect diminished with increasing current age. For example, the odds of having an STI for an 18year-old who first had intercourse at age 13 were more than twice those of an 18-year-old who first had intercourse at age 17 (prevalence odds ratio 5 2.25, 95% confidence interval: 1.42, 3.59). In contrast, the odds of having an STI among 24-year-olds with first intercourse at age 13 versus those with first intercourse at age 17 were the same (prevalence odds ratio 5 1.11, 95% confidence interval: 0.88, 1.39). Thus, earlier initiation of sexual intercourse is strongly associated with STIs for older adolescents but not for young adults over age 23 years. adolescent behavior; Chlamydia trachomatis; Neisseria gonorrhoeae; sexually transmitted diseases; Trichomonas vaginalis

The addition of nucleic acid amplification testing to an HIV testing algorithm significantly increases the identification of cases of infection without impairing the performance of diagnostic testing. The detection of highly contagious, acutely infected persons creates new opportunities for HIV surveillance and prevention.