Obesity is increasing in epidemic proportions in most countries and poses a public health problem by enhancing the risks for cardiovascular diseases and metabolic disorders such as type 2 diabetes. According to the Centers for Disease Control and Prevention, the prevalence of overweight and obesity has increased sharply for both adults and children since the 1970s. Data from two National Health and Nutrition Examination surveys show that among adults aged 20-74 years the prevalence of obesity increased from 15 percent (in the 1976-80 survey) to 32.9 percent (in the 2003-04 survey).

The two surveys also show increases in overweight children and teens. For children aged 2-5 years, the prevalence increased from 5 percent to 13.9 percent; for those aged 6-11 years, prevalence increased from 6.5 percent to 18.8 percent; and for those aged 12-19 years, prevalence increased from 5 percent to 17.4 percent.

In a new study discussed in Nature, a team has found that there is a direct correlation between the measures of fat mass (measured from body mass index (BMI) and fat cell volume in subcutaneous fat, which represents about 80 percent of all fat, and visceral fat.

Working at the University of Oxford and The Open University, Dr Lynne Cox and Dr Robert Saunders say they have found a fast and effective way to investigate important aspects of human aging.

Their discovery of a gene in fruit flies means they can now be used to study the effects aging has on DNA. The researchers demonstrate the value of this model in helping us to understand the critical aspects of human aging at cellular, genetic and biochemical levels.

Dr Lynne Cox from the University of Oxford said: "We study a premature human ageing disease called Werner syndrome to help us understand normal aging. The key to this disease is that changes in a single gene (called WRN) mean that patients age very quickly. Scientists have made great progress in working out what this gene does in the test tube, but until now we haven’t been able to investigate the gene to look at its effect on development and the whole body. By working on this gene in fruit flies, we can model human aging in a powerful experimental system."

At first, fruit flies eat like horses. Hatching inside over-ripe fruit where they were laid, they feed wildly in the sugar-rich environment until nature sends them an offer they can’t refuse. To survive, they must leave the fruit, wander off and burrow into the earth where they avoid food as if it were poison. Only then can the larvae grow and hatch into flies that will take wing to lay their own eggs.

Now, a team of researchers from the University of Georgia has discovered for the first time that the important developmental switch from food attraction to aversion in the fruit fly larva is controlled by a timing mechanism in the brain and its sensory system. The study shows how this important avoidance mechanism has been recruited into evolutionary processes to promote development and could one day lead to new methods of controlling pain in humans and other animals.

Fruit flies can’t really stay in the rotting fruit where they are laid. Not only do they risk drowning in the ripening fluid, they are increasingly exposed to harmful microorganisms that can kill them. To escape, the larvae “wander” out and burrow into the ground.

In a paper recently published in Cortex, Jan Lonnemann (RWTH Aachen University, Germany) and colleagues report that many children at the age of 8-9 years seem to represent numbers spatially. Interestingly, boys using this kind of representation tended to have better calculation abilities, while girls who represent numbers spatially tended to show poorer calculation abilities.

The authors assume that these differences may be due to gender-specific thinking styles: for boys, who may prefer visual-spatial thinking styles, it seems to be helpful to represent numbers spatially when being confronted with calculation problems, whereas for girls preferring verbal thinking styles it may be even detrimental.

Evidence for a connection between number and space processing comes from behavioral, patient, and brain imaging data, but only a few studies have addressed this issue in children.

Stem cells, the body's wonder tool, are extremely versatile. They can develop in 220 different ways, transforming themselves into a correspondingly diverse range of specialized body cells.

Biologists and medical scientists plan to make use of this differentiation ability to selectively harvest cardiac, skin or nerve cells for the treatment of different diseases. However, the stem cell culture techniques practiced today are not very efficient. What proportion of a mass of stem cells is transformed into which body cells? And in what conditions?

“We need devices that keep doing the same thing and thus deliver statistically reliable data,” says Professor Günter Fuhr, director of the Fraunhofer Institute for Biomedical Engineering IBMT in St. Ingbert.

Being obese can increase the risk of Alzheimer’s Disease by as much as 80 percent, according to a study in the May issue of Obesity Reviews. But it's not just weight gain that poses a risk. People who are underweight also have an elevated risk of dementia, unlike people who are normal weight or overweight.

US researchers carried out a detailed review of 10 international studies published since 1995, covering just over 37,000 people, including 2,534 with various forms of dementia. Subjects were aged between 40 and 80 years when the studies started, with follow-up periods ranging from three to 36 years.

The review, which included studies from the USA, France, Finland, Sweden and Japan, also included a sophisticated meta-analysis of seven of the studies, published between 2003 and 2007 with a follow-up period of at least five years.