What is the best way to address the obesity epidemic? Several experts debated the subject in the most recent issue of the British Medical Journal. 

Researchers from the Children's Hospital at Westmead and the University of Sydney in Australia  argue that physical inactivity is just one marker and that there is substantial evidence that unhealthy diets low in fibre and high in sugar and large portion size are also responsible for obesity and the diseases associated with it.

The debate over what wiped out the dinosaurs has been raging for three decades, and researchers writing in Science say they have compiled enough evidence to end it. They say it really was an asteroid that was responsible for the mass extinction. 

Scientists first proposed the asteroid impact theory of dinosaur mass extinction 30 years ago. The discovery of a massive crater at Chicxulub [CHICK-shuh-loob], in Mexico's Yucatán Peninsula in 1991, strengthened that hypothesis. The Chicxulub crater is more than 120 miles wide and scientists believe it was created when an asteroid more than six miles wide crashed into Earth 65 million years ago. 

A Body Mass Index (BMI) of 30 or above, a standard indicator of obesity, is not associated with poorer health among adults under age 40, according to a new study.

In addition, researchers found that across all age groups studied, from 25 to 70 years, there was little difference in the current health status in normal-weight vs. overweight people based on the medications they took.

The study was published in the International Journal of Obesity.

The researchers acknowledge that health problems in older adults with BMIs of 30 or higher might be traced back to carrying extra weight in young adulthood. Among people age 40 or older, use of medication was significantly higher among adults considered to be obese compared to adults with a normal weight.

For some people, raising "good" cholesterol levels isn't necessarily a healthy choice, according to a new study in Arteriosclerosis, Thrombosis, and Vascular Biology. The study is the first to find that a high level of the supposedly good cholesterol places a subgroup of patients at high risk for recurrent coronary events, such as chest pain, heart attack, and death.

Researchers at the University of Leeds have found that a compound known as pyrophosphite may have been an important energy source for primitive lifeforms.

The findings, published in the journal Chemical Communications, are the first to suggest that pyrophosphite may have been relevant in the shift from basic chemistry to complex biology when life on earth began. Since completing this research, the authors have found even further evidence for the importance of this molecule and plan to further investigate its role in abiogenesis - how life on Earth emerged from inanimate matter billions of years ago.

Scientists from the University of Alabama, Huntsille have developed a new way to use satellite instruments to measure surface temperatures over most of the world's land area. 

The new technique developed by Dr. Roy Spencer and Dr. Danny Braswell, both research scientists in the Earth System Science Center at The University of Alabama in Huntsville, uses microwave sensors on NOAA and NASA satellites to collect surface temperature data over virtually all of Earth's land area.

They say they hope the new system will provide a stable method for monitoring climate change without some of the problems associated with the existing network of surface thermometers.