The foods, under development at the Clore Laboratory at the University of Buckingham, will be supplemented with leptin, the hunger hormone. Those who take the foods early in life should remain permanently slim. 'Like those people who are lean by nature even though they overeat , like we all do , they will tend to be inefficient in terms of using energy,' says Mike Cawthorne, who heads the Metabolic Research group at Clore.

Cawthorne's group has already demonstrated that supplementing infant rats' diets with leptin means that they never get fat or develop diabetes (AM J Physiol Regul Integr Comp Physiol, doi: 10.1152/ajpregu.00676.2006). Even animals fed a high-fat diet remained slim.

Leptin, the fat hormone that turns off hunger in the brain, is produced in the body throughout life. Its discovery was heralded as a major breakthrough, but research in adults proved disappointing because individuals soon seemed to resist its hunger-quenching effect.

But Cawthorne says this time things are different. Providing leptin earlier enough effectively hard-wires the body's energy balance. In fact, whether one is fat or thin may be determined before birth. Feeding the hormone to pregnant rats has been found to have a lifelong impact on their offspring's predisposition to obesity. Animals born of leptin-treated mothers remain lean even when fed a fat-laden diet, while those from untreated dams gained weight and developed diabetes.

The difference boils down to energy expenditure. The offspring of leptin-treated mothers burn up more energy. 'The infants are permanently inefficient in terms of using energy,' says Cawthorne.

Leptin-based products may also find their way into the pet obesity market.

Edinburgh researcher Jonathan Seckl says. 'We need to know whether leptin is acting pre- and post-natally, figure out how it works, and dissect the possible side-effects before this becomes a potential approach for humans. Nonetheless, this is good science,' he says.

sci.mond

Current recommendations call for people from age 50 to 69 to get 400 international units (IUs) of vitamin D per day and for those over age 70 to get 600 IUs. Many researchers, however, suggest that higher amounts may be needed.

Higher amounts of vitamin D may be needed for the preservation of muscle strength and physical function as well as other conditions such as cancer prevention, said Houston. The current recommendations are based primarily on vitamin D's effects on bone health.

The research is supported by the Italian Ministry of Health and in part by the National Institute on Aging. Co-researchers were Gary Schwartz, Ph.D., and Stephen Kritchevsky, Ph.D., both with Wake Forest, Matteo Cesari, M.D., Ph.D, with the University of Florida, Luigi Ferrucci, M.D., Ph.D., with the National Institute on Aging, Dario Maggio, M.D., and Antonio Cherubini, M.D., Ph.D, both with the University of Perugia in Italy, Mary Ann Johnson, Ph.D., with the University of Georgia, and Benedetta Bartali, R.D., with Cornell University.

Wake Forest University Baptist Medical Center is an academic health system comprised of North Carolina Baptist Hospital and Wake Forest University Health Sciences, which operates the university's School of Medicine. U.S. News & World Report ranks Wake Forest University School of Medicine 18th in family medicine, 20th in geriatrics, 25th in primary care and 41st in research among the nation's medical schools. It ranks 35th in research funding by the National Institutes of Health. Almost 150 members of the medical school faculty are listed in Best Doctors in America.

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