By Charlotte Rixon

With so much advice about what and when to eat, it is no wonder the British public is confused about the best way to lose weight.

 

 

The latest Government figures on obesity make bleak reading. Around one in four adults in England are now obese (26 per cent of men and 24 per cent of women); one-fifth of children are overweight or obese when they begin school, but this figure rises to one-third by the time they leave primary school. Obesity now costs the NHS more than £5bn per year.

While increasing physical activity undoubtedly brings health benefits, growing evidence suggests that diet is the main factor behind the nation’s ever-expanding waistlines. The British Medical Association (BMA) estimates that a poor diet is responsible for 70,000 deaths a year and has the greatest impact on the NHS budget, while experts writing in the British Journal of Sports Medicines in April last year warned that “even athletes can’t outrun a bad diet”.

In recent years, weight loss research and advice has shifted away from counting calories towards encouraging people to make sustainable dietary changes to improve health outcomes at individual and population level. So let’s consider some of the latest thinking on diet and weight loss.

 Advice has shifted away from counting calories towards encouraging people to make sustainable dietary changes

 

Spotlight on sugar

One element of today’s diets that has come in for particular criticism lately is sugar. Last year, following advice from the Scientific Advisory Committee on Nutrition (SACN), the Government halved the recommended maximum intake of sugar from 10 to 5 per cent of daily energy consumption – a recommendation which, if practised by the majority of the population, could save the NHS £576m each year. However, persuading individuals and families to meet this ambitious target is a huge challenge.

A recent survey by the National Obesity Forum (NOF) found that one in three Britons are unwilling to make simple dietary substitutions to reduce their sugar intake, while a study commissioned by Public Health England (PHE) to mark the launch of its new Sugar Smart campaign revealed that five-year-olds consume their body weight in sugar every year.

“Children are having too much sugar – three times the maximum recommended amount,” says PHE chief nutritionist, Dr Alison Tedstone. “This can lead to painful tooth decay, weight gain and obesity, which can also affect children’s wellbeing as they are more likely to be bullied, have low self-esteem and miss school.”

To help wean the nation off sugar, the BMA, PHE, TV chef Jamie Oliver and the NOF have all called for a sugar tax or levy. A PHE review released last October proposed the introduction of a 20 per cent levy on sugary snacks and drinks, but in a public health manifesto published last month, the NOF argued for a 50 per cent tax on sugar sweetened beverages but rejected calls to tax high sugar foods.

“Anything less than a 50 per cent tax on sugary drinks will be insufficient as a disincentive to consumers,” argues Professor David Haslam, NOF chairman. “We do not currently support taxing food products – this would be unfair to particularly low-income families. But sugary drinks have no place in anyone’s diet.”

Other PHE recommendations include restrictions on price promotions, control of the marketing and advertising of sugary products to children, and a reduction in the sugar content of everyday foods and drinks. The NOF encourages people to make simple dietary substitutions, including swapping sugary cereals for porridge with berries, replacing sugar in tea or coffee with sweetener, and exchanging fizzy drinks for diet equivalents or sparkling water.

“There is no silver bullet solution to the nation’s bad sugar habit,” says Dr Tedstone. “A broad and balanced approach is our best chance of reducing sugar consumption to healthier levels and to see fewer people suffering the consequences of too much sugar in their diet.”

Fad diets

With so much focus on sugar as a cause of obesity, it might appear somewhat surprising that the British Dietetic Association (BDA) has chosen the ‘no sugar diet’ as its number one celebrity diet to avoid in 2016.

However, while the BDA advocates cutting down on free sugars, ‘no sugar’ or ‘sugar-free’ diets are unbalanced because they promote the elimination of all sugar from the diet, including those found in vegetables, fruits and dairy products. In addition, the diet plans cause confusion by promoting sugar ‘alternatives’ such as agave, maple syrup or honey, which are free sugars in a different form.

The BDA also warns slimmers against extreme, unbalanced diets that centre around the consumption of a single ‘super food’, such as the ‘all-kale and chewing gum diet’, or those lacking in scientific evidence, such as the ‘bullet-proof’ diet, which advocates starting the day with a 500-calorie ‘bullet-proof’ coffee containing butter and coconut oil.

“The bottom line is, if it sounds too good to be true, then it probably is,” says Sian Porter, consultant dietitian and BDA spokesperson. “The simple fact is there is no ‘wonder diet’ just as there are no ‘super foods’ and no one diet fits all.” What isn’t super “is the way many marketing machines coin certain phrases to make you think there is some magic wand approach to losing weight.”

Labelling measures

This month, the Local Government Association (LGA), a lobby group representing local authorities, called for calorie information to be included on the labels of alcoholic drinks to help tackle the obesity crisis by raising public awareness of the ‘hidden’ calories in alcohol.

According to the Royal Society for Public Health (RSPH), which also wants to see calorie information on alcoholic drinks, five pints of 4 per cent strength beer is equivalent to three burgers. However, calories from alcohol are classed as ‘empty calories’ because they have no nutritional value, and by drinking alcohol the amount of fat the body burns for energy is reduced.

Eighty per cent of members of the public polled by the LGA did not know that a large glass of wine contained up to 228 calories (the same as a doughnut), while around nine in 10 were unaware that there are around 180 calories in a pint of lager. However, twothirds of the survey participants were in favour of labelling bottles and cans with calorie levels.

“Most people are aware that excessive alcohol can lead to serious health problems like liver and heart damage and an increased risk of cancer, but the amount of calories from an average night’s drinking is not so well-known,” says Izzi Seccombe, LGA community wellbeing spokesperson. “Providing people with the right information allows them to make choices about what they eat and drink.”

Another labelling intervention that may encourage healthier choices is that of ‘activity equivalent’ calorie labels. The RSPH has called for pictorial icons to be displayed alongside other nutritional information on food and drink packaging to indicate the amount of physical activity required to burn off the calories consumed.

The Society’s research found that 63 per cent of people would support activity equivalent labels, with over half believing that it would cause them to make positive behavioural changes, such as choosing healthier products, eating smaller portions or doing more physical exercise.

Such a move could lead to a better understanding of the energy contents of various foods and drinks, says BDA honorary chairman Fiona McCullough.“It leads people to think about the level of physical activity required to burn off the energy in a product and this could help them to make better informed decisions when choosing what to consume.”

 

 

Time restricted feeding

A new area of research suggests that altering the timeframe in which eating occurs could help people lose weight and reduce the metabolic effects of obesity.

Studies into ‘time restricted feeding’ (TMF) at the Salk Institute in California have found that mice gain less weight when their access to food is restricted to an eight-hour window compared with mice that consume the same quantities of food over a 24-hour period.

The theory was recently put to the test in humans by researchers at the University of Surrey. Sixteen volunteers were recruited, half of whom restricted their mealtimes by moving breakfast 90 minutes forward and dinner 90 minutes back. After 10 weeks, the restricted mealtimes group showed a significantly healthier change in fasting blood sugar and cholesterol levels between the start and end of the experiment and also lost body fat, although there was no difference in triglyceride levels between the groups.

The researchers speculate that bringing mealtimes closer together had a positive effect on metabolic factors by allowing the body an additional three hours of fasting time in which to repair itself. In addition, by eating their evening meal earlier in the day, the participants avoided a surge in blood fat and glucose levels.

TMF may offer a more sustainable alternative to the popular dieting method of intermittent fasting, which involves restricting calories for two days a week. In fact, according to the researchers, people may not even need to practise TMF every day to see benefits.

Portion sizes

Reducing portion size has been standard weight management advice for many years, and yet portion and recommended serving sizes have been steadily increasing over the past few decades. 

Research by the British Heart Foundation revealed that ready meals and suggested servings of certain products had increased by as much as 98 per cent between 1993 and 2013, while a recent Cochrane Review concluded that food consumption has increased in line with exposure to larger servings in supermarkets and restaurants and also through marketing images.

In order to ‘recalibrate’ the amount of food people typically consume at one sitting, experts have called upon the public, the food industry and politicians to support portion downsizing.

In an analysis published in the BMJ in December 2015, public health expert from the University of Cambridge, Professor Theresa Marteau and colleagues proposed various measures, including:

• Reducing the size of single servings of high calorie foods such as crisps and confectionery
• Reducing the availability of larger portions and package sizes, such as removing the biggest fizzy drink option
• Restricting price promotions on larger portion sizes
• Making smaller tableware, including plates, cups, glasses and cutlery, the default for self-service and served foods and drinks
• Designing tableware to encourage smaller mouthfuls, such as shallow plates and straight sided glasses.

The experts conclude that successful interventions, if they are implemented at sufficient scale, have the potential to help prevent obesity as part of a wider obesity strategy. “Aligning the will of the public, private industry and political leadership is key to progress,” they say.