Researchers have claimed that there has been a startling increase in rates of obesity and overweight in both adults (28 per cent increase) and children (up by 47 per cent) in the past 33 years, with the number of overweight and obese people rising from 857 million in 1980 to 2.1 billion in 2013.

However, the rates vary widely throughout the world with more than half of the world's 671 million obese individuals living in just ten countries-the USA (more than 13 per cent), China and India (15 per cent combined), Russia, Brazil, Mexico, Egypt, Germany , Pakistan, and Indonesia, and (listed in order of number of obese individuals).

Over the past three decades, the highest rises in obesity levels among women have been in Egypt, Saudi Arabia, Oman, Honduras and Bahrain, and among men in New Zealand, Bahrain, Kuwait, Saudi Arabia, and the USA.

In high-income countries, some of the highest increases in adult obesity prevalence have been in the USA (where roughly a third of the adult population are obese), Australia (where 28 per cent of men and 30 per cent of women are obese), and the UK (where around a quarter of the adult population are obese).

The findings come from a comprehensive new analysis of the global, regional, and national prevalence of overweight and obesity in adults aged 20 years and older and children and adolescents aged 2-19 years between 1980 and 2013.

Led by Professor Emmanuela Gakidou from the Institute for Health Metrics and Evaluation at the University of Washington in the USA, a team of international researchers performed a comprehensive search of the available data from surveys, reports, and the scientific literature to track trends in the prevalence of overweight (body mass index of 25kg/m2 or higher) and obesity (BMI of 30kg/m2 or higher) in 188 countries in all 21 regions of the world from 1980 to 2013.

The study finding also revealed that in the developed world, men have higher rates of obesity than women, while the opposite is true in developing countries. Currently, 62 per cent of the world's obese people live in developing countries.

The greatest gain in overweight and obesity occurred globally between 1992 and 2002, mainly among people aged between 20 and 40.

The study has been published in journal The Lancet.

Researchers have taken a major step forward understanding how enzymes 'edit' genes, which has paved the way for correcting genetic diseases in patients.

Researchers at the Universities of Bristol, Munster and the Lithuanian Institute of Biotechnology have observed the process by which a class of enzymes called CRISPR - pronounced 'crisper' - bind and alter the structure of DNA.

The results have provided a vital piece of the puzzle if these genome editing tools are ultimately going to be used to correct genetic diseases in humans.

CRISPR enzymes were first discovered in bacteria in the 1980s as an immune defence used by bacteria against invading viruses. Scientists have more recently shown that one type of CRISPR enzyme - Cas9 - can be used to edit the human genome - the complete set of genetic information for humans.

These enzymes have been tailored to accurately target a single combination of letters within the three billion base pairs of the DNA molecule. This is the equivalent of correcting a single misspelt word in a 23-volume encyclopaedia.To find this needle in a haystack, CRISPR enzymes use a molecule of RNA - a nucleic acid similar in structure to DNA. The targeting process requires the CRISPR enzymes to pull apart the DNA strands and insert the RNA to form a sequence-specific structure called an 'R-loop'.

The global team tested the R-loop model using specially modified microscopes in which single DNA molecules are stretched in a magnetic field. By altering the twisting force on the DNA, the researchers could directly monitor R-loop formation events by individual CRISPR enzymes.

This allowed them to reveal previously hidden steps in the process and to probe the influence of the sequence of DNA bases.

The results have been published in the Proceedings of the National Academy of Sciences (PNAS).

Scientists have found that a drug used to treat multiple sclerosis may pave the way for a pill that can erase bad memories.

Researchers have found that mice given fingolimod, a drug approved by the US Food and Drug Administration for treatment of multiple sclerosis, had enhanced 'memory extinction' of previous experiences that had caused pain.

If the effects of the drug apply to humans, it may offer new treatment options for sufferers of post-traumatic stress, phobias and eating disorders.

Fingolimod, available as a tablet under the brand name Gilenya, treats remitting forms of MS by suppressing the immune system.

Sarah Spiegel, of the Virginia Commonwealth University, in Richmond, and colleagues found that it can also inhibit an enzyme called histone deacetylase, a key protein that regulates gene expression, 'The Times' reported.

When fed to mice, fingolimod crossed the blood-brain barrier and was faster at extinguishing "previously acquired fear memories".

The mice were put in a chamber where their feet were exposed to a mild electric shock, and when returned to the cage the extent to which they froze to the spot was recorded as a measure of anxiety.

This complete lack of movement, known as "freezing" - a fear response in rodents providing a good indication of memory - subsided rapidly after receiving the drug.

The study is published in the journal Nature Neuroscience.

An analysis by Oxford University psychiatrists has shown that serious mental illnesses reduce life expectancy by 10-20 years - a loss of years that's equivalent to or worse than that for heavy smoking.

Yet mental health has not seen the same public health priority, despite these stark figures and the similar prevalence of mental health problems, the Oxford scientists said.

1 in 4 people in the UK will experience some kind of mental health problem in the course of a year, it is estimated. Around 21 percent of British men and 19 percent of women smoke cigarettes.

The researchers said that the figures should galvanise governments and health and social services to put a much higher priority on how mental health services can prevent early deaths.

The average reduction in life expectancy in people with bipolar disorder is between 9 and 20 years, it's 10-20 years for schizophrenia, between 9 and 24 years for drug and alcohol abuse, and around 7-11 years for recurrent depression.

The loss of years among heavy smokers is 8-10 years.

All diagnoses studied showed an increase in mortality risk, though the size of the risk varied greatly. Many had risks equivalent to or higher than heavy smoking (see table in notes for editors).

"We found that many mental health diagnoses are associated with a drop in life expectancy as great as that associated with smoking 20 or more cigarettes a day," Dr Seena Fazel of the Department of Psychiatry at Oxford University said.

"There are likely to be many reasons for this. High-risk behaviours are common in psychiatric patients, especially drug and alcohol abuse, and they are more likely to die by suicide. The stigma surrounding mental health may mean people aren't treated as well for physical health problems when they do see a doctor," Dr Fazel said.

The findings are published in the open access journal World Psychiatry.

Here is some good news for wine lovers as new studies suggest that drinking wine can help you avoid a visit to your dentist as it is believed to fight cavities.

Researchers had previously discovered that red wine is also very beneficial for health as it contains resveratrol which is associated with beneficial health effects in ageing, inflammation and metabolism.

To prove this point, researchers grew cultures of bacteria responsible for dental diseases as a biofilm.

They dipped the biofilms for a couple of minutes in different liquids -- red wine, red wine without the alcohol, red wine spiked with grape seed extract, and water and 12 percent ethanol -- for comparison.

Cavities, periodontal disease and tooth loss affect an estimated 60 to 90 percent of the global population.

The problems start when certain bacteria in the mouth get together and form biofilms, which are communities of bacteria that are difficult to kill.

Research has suggested that polyphenols, grape seed extract and wine can slow bacterial growth, said the study that appeared in the Journal of Agricultural and Food Chemistry.