Just fifteen minutes of brisk activity a day could halve the risk of children becoming obese, say researchers. They discovered a small amount of moderate exercise could have far reaching benefits.

The number of fat children has doubled in ten years with one in four aged 11-15 now classified as obese. Almost half of girls are obese or overweight. Junk food, sedentary lifestyles and the couch potato use of TV as an ‘electronic babysitter’ are blamed for creating the problem. At the same time, levels of inactivity have soared as many children no longer take part in competitive sports at school and playing fields have been sold off.

The Bristol University Children of the 90s research project monitored 5,500 12-year-olds. It found 15 minutes of extra activity per day cut the risk of becoming obese by more than half in boys and at least 40 per cent in girls.

This study provides some of the first robust evidence on the link between physical activity and obesity in children. We know that diet is important – but what this research tells us is that we mustn’t forget about activity. It’s surprising how even small amounts of exercise appear to have dramatic results. In the latest study, published in March 2007 in the journal PLoS (Public Library of Science) Medicine, children were given a monitor to wear for up to a week which kept track of their movements. The research showed that the level of intensity of the activity was critical.

Moderate to vigorous activity was much more effective, which means exercise that makes a child get a little out of breath, but the study also indicated that it may be something quite small that makes a difference – such as how children get to school, whether they are walking, cycling or being driven in a car.

According to a study by Japanese scientists, sniffing lavender or rosemary oil for just five minutes a day can reduce levels of a harmful stress hormone called cortisol.

It is known to cause oxidative stress, a destructive process that damages healthy cells. In the latest study, researchers at Meikal University, Japan, recruited 22 healthy volunteers and took saliva samples to test for a range of substances including cortisol.

Each one had to spend five minutes inhaling lavender or rosemary oil before the tests were repeated. The results in the Journal of Psychiatry Research showed a sharp drop in cortisol levels after sniffing the oil.

Missing breakfast has been shown to raise cholesterol levels in a small study at the University of Nottingham.

The study also found that women tend to eat more calories during the day if they had skipped breakfast, with implications for weight gain if they continued to skip breakfast over the long term.

Ten healthy women of normal weight were asked to eat breakfast before 8 am for two weeks followed by normal mealtimes. They were later asked to eat breakfast at midday for two weeks. Cholesterol levels were found to be higher after skipping breakfast.