If you think the world is conspiring to make you fat, you are probably right. Almost everything, from how many labour-saving gadgets you own to how fast you eat and how overweight your ancestors were, controls how quickly you add to that dreaded number on your weighing scale.
This week, several studies have added to the already staggering list of things that cause weight gain. Eating three slices of white bread a day raises your chances of being overweight or obese in five short years by as much as 40% compared with people who eat it once a week, reported researchers from Spain at the European Congress on Obesity.
Those who ate wholemeal bread — which has more fibre and complex carbohydrate that make you feel full for longer — were not overweight five years on, suggesting that people who eat white bread tend to have more unhealthy diets overall.
But it’s not food alone that makes you fat. How many calories you burn is affected by the body’s circadian rhythm, the 24-hour cycle “body clock” synchronised with the natural light cycle that regulates many physiological functions, such as sleeping and eating. Though most infamously implicated in jet lag, an out-of-whack also causes weight gain.
This week, British researchers have added sleeping with the light on to the list of taboos for people fighting off extra weight.
Sleeping in lit rooms raised both weight and waist size in more than 113,000 women taking part in Britain’s Breakthrough Generations Study that followed the women for 40 years to identify root causes of breast cancer. Obesity is a known risk factor for the disease.
Switching from the day shift to working evenings or nights also add to weight and waistlines over two years, found a large Australian study of nurses. In contrast, those who switched from working at night to working in the day lost weight.
Psycho-social factors have a role, such as mindless snacking, a job that keeps you behind a desk most hours, and spending time with people who are unfit — you are more likely to eat and do what your friends are doing.
The Köhler Effect —where weaker individuals, when placed on a team, perform better than they would on their own — works in sports but seems to fail in social situations. Highly-motivated partners were more likely to sink to the lethargic level of the slacker partner, reported a review this week of couples’ gym memberships.
Little wonder then that there’s been a startling rise obesity and overweight in both adults (28% increase) and children (up by 47%) in the past 33 years, up from 857 million in 1980 to 2.1 billion in 2013. More than half of the world’s 671 million obese living in just 10 countries — the US (more than 13%), China and India (15% combined), Russia, Brazil, Mexico, Egypt, Germany, Pakistan, and Indonesia, reports the Global Burden of Disease Study 2013 in The Lancet.
What’s most worrying is data from children. In developed countries, close to one in four children are overweight and obese (24% boys and 23% girls). In developing countries, its 13% but growing in both boys and girls.
Eating too much kills more people worldwide than starvation, says the World Health Organisation, with at least 2.6 million people dying each year of obesity-related diseases, such as diabetes, heart disease and certain cancers.
The upside is that obesity rates are slowing down in developed countries, and are likely to do so in the rest of the world as awareness rises.
While some serious gymming or running for an hour can help you burn off around 300-400 kcal (you need to burn 7,700 kcal to lose one kg) smaller changes — such as walking for 30 minute at a moderate pace can burn 120 kcal — can help you shed at a slower, more manageable pace.
Other doable suggestions are doing housework during television commercial breaks to burn up to 40 calories per hour of TV viewing; snacking on fruit instead of biscuits and chips as to reduce calorie intake by around 50-100 kcal each day; and getting up to talk to a colleague or drink water at least once every hour at work, which can use up around 120 kcal each day.
Even fidgeting has its benefits, with people who tap their feet while sitting burning up to 350 kcal a day more than people who stay still. So get moving, even if it is only to fidget.