BALTIMORE -- An astonishing doubling in American obesity took place in the two decades after the nation's bicentennial, epidemiologists reported.

BOSTON -- A lack of vitamin D and calcium in the diet may increase the risk for the metabolic syndrome and type 2 diabetes in patients with impaired glucose tolerance, nutrition researchers found.

COLLEGE PARK, Md. -- The FDA won't rule out the possibility that tomatoes are cancer-fighters, but it considers the evidence supporting that claim to be exceedingly flimsy.

LORENSKOG, Norway -- B-type natriuretic peptides have earned a new vote of confidence as a prognostic biomarker for low-risk patients with stable coronary disease.

SAN FRANCISCO -- A drug already approved as a smoking-cessation aid might also have a role in the treatment of alcohol dependence, if results achieved in animals carry over to humans.

PHILADELPHIA -- Not only did prophylactic antibiotic therapy fail to reduce recurrence of urinary tract infections in young children, it was linked to an increase in resistant infections.

EAST HANOVER, N.J. -- The FDA has approved a rivastigmine transdermal patch for mild to moderate Alzheimer's disease, Novartis announced here.

PHILADELPHIA -- Half of otherwise healthy children and adolescents in the northeastern United States don't get enough vitamin D, researchers found.

LOS ANGELES -- Cigarette, pipe, and cigar smoking, and chewing tobacco as well, were all associated with a lower risk for Parkinson's disease in an analysis of pooled data from 11 studies.

SYDNEY, Australia -- Cataracts and age-related macular degeneration in middle-age may be warning signs of a higher mortality risk for those younger than 75, researchers suggested.

ROCHESTER, New York -- Somnolence, edema, and hallucinations in patients with early-stage Parkinson's disease may be related as much to co-morbid disease and other factors as they are to medication.

TORONTO -- Prostate cancer and colorectal cancer appear to have a common genetic risk factor.

NEW HAVEN, Conn. -- Heart attack death rates are lower overall at hospitals ranked "America's Best" in cardiac care by U.S. News and World Report than at other hospitals, but not every one was a stellar performer, researchers said.

BIRMINGHAM, Ala. -- Two-thirds of nursing home residents here did not receive regular eye exams despite the fact that 57% of the residents had evidence of visual impairment.

MONTREAL -- Delayed diagnosis of childhood cancer continues to confound efforts to achieve the best possible clinical outcomes, a review of the pediatric oncology literature suggests.

LYONS, France -- Infertile women who use complementary or alternative therapies are about 20% more likely to have persistent reproductive problems than non-users, investigators reported here.

LYON, France -- As the complexity of assisted reproduction techniques increases, so does the frequency of umbilical cord abnormalities, Belgian investigators reported here.

BALTIMORE -- About half of children who develop autism may be diagnosable by 14 months of age, researchers found in a small study that dropped the bar for early diagnosis by six months.

HOUSTON -- Standard helical PET-CT cardiac imaging produces false-positives 40% of the time, although most of the errors can be identified and corrected before inappropriate treatment.

ROCKVILLE, Md. -- Some patients may be at greater risk of lung cancer because of variations in genes involved in inflammatory responses, researchers here said.