Britain now has one of the highest obesity rates in Europe. Will the recently-announced tax on sugar help? It’s unlikely, says Huddersfield University sport and exercise scientist Matthew Haines

A huge slab of fake fat sits on the desk of Senior Lecturer Matthew Haines in his office at Huddersfield University. It represents 5lbs (2.2kgs) of sub-cutaneous fat, of the sort that a growing number of us have in plenty, and is used as a teaching aid.

Given the obesity epidemic in the UK, body fat is a topic that’s very much on the curriculum for students of sport, exercise and nutrition, some of whom may well find their way into the burgeoning weight management industry.

As Matthew, a Senior Lecturer in Health and Wellbeing, points out, the NHS is already struggling to cope with long-term health conditions caused by obesity and it’s estimated that by 2030 as many as 74% of men and 64% of women in the UK will be overweight.

Nutrition, says Matthew, who is conducting research into exercise in diabetic and pre-diabetic patients, is only part of the solution, which is why he believes George Osborne’s tax on sugary drinks will have little effect.

He explains: “What we try to instil in our students is that they should look at preventative strategies and changing behaviour; promoting physical activity. Nutrition is just part of the issue.

Matthew Haines, sport and exercise scientist at Huddersfield University

“We live in an obesogenic environment, with sedentary jobs and transport so that we don’t have to be physically active at all. We have almost unlimited access to energy dense foods - the opposite of our ancestral past.

“I think it would have been beneficial to make healthier foods cheaper rather than put a tax on sugar. I don’t think the sugar tax will have any impact on obesity.”

Such is the scale of the nation’s weight problem that there’s hard cash to be made from promoting weight loss ‘diets’, many of which claim to have a scientific basis.

Matthew, who teaches obesity prevention and management to post-graduate students, recently wrote a blog for the university’s website on one of the latest fads - the Sirtfood Diet. It is, he says, an example of bad science. But he admits that most restrictive, ‘fad’, diets don’t bear close scientific scrutiny.

As he puts it: “Few academic disciplines are so deeply infected by fads, frauds and quackery as nutrition.”

The Sirtfood Diet is described as a ‘revolutionary way to lose 7lbs in 7 days’ and promises that dieters can enjoy a range of foods, including red wine, dark chocolate and blueberries (although there’s a lot of not-so-attractive kale involved as well). It is based on the idea that certain foods activate a family of proteins known as sirtuins and that sirtuins ‘switch on your body’s fat-burning powers, supercharge weight loss and help stave off disease’. However, the early stages of the diet severely restrict calorie intake.

Matthew says that while sirtuins are involved in a number of the body’s cellular processes, including metabolism and ageing, there is no compelling scientific proof that the Sirtfood Diet works by any other means than cutting calories. He points out: “It would be a colossal over-extrapolation to assume that laboratory research conducted on mice, yeast and human stem cells has any bearing on real-world health outcomes.”

A tray of glasses of red wine

He says it’s virtually impossible to conduct controlled research on human beings and their diets because there are just too many variable factors that could affect the outcome - exercise levels and smoking, for example.

Like many diets, the Sirtfood diet promises rapid weight loss. It achieves this initially by instructing dieters to consume no more than 1,000 calories a day. As Matthew says, this causes a loss of glycogen (a stored form of carbohydrate) and water, which manifests as weight loss. However, the body can quickly replenish this when dieters fall off the wagon, and most people inevitably do.

He explained: “Our own physiology has elaborate systems to find and eat food. Dieters are up against a potent enemy. Any diet that’s too restrictive means that it’s not going to last. People only lose weight in the short term.

“There is also evidence that yo-yo dieting and restrictive diets lead to weight gain. On restrictive diets you lose some lean tissue as well as fat. Your body is good at replacing the fatty tissue but it’s more difficult to replace the lean tissue, so over time you are making yourself fatter and fatter.”

Matthew has a special interest in exercise for health and sport and is himself a runner and mountain biker. While exercise doesn’t necessarily burn as many calories as we might want it to, he says it is one of the keys to weight management. “When you exercise, your basal metabolic rate increases and remains higher for some period afterwards. But the benefits of exercise are relatively short-lived, which is why you have to top it up regularly. Our bodies are designed to be moving, not sitting about all day.”

Current guidelines are that adults should exercise for a minimum of 150 minutes a week. Getting out for a half hour walk once a day could make all the difference.

Group of people doing stretching exercises in field

If the UK is to beat the obesity crisis and stem the increasing numbers of people becoming diabetic - there are up to 4m people with diabetes, mostly Type 2 - then we need to forget about quick fix diets and start making long-term lifestyle changes.

Matthew added: “One third of the population is pre-diabetic, that means if they don’t change their lifestyles then they will become diabetic.

“There’s an obesity problem now in children and if you are an overweight child then there is research to suggest that you will become an overweight adult. You can grow more fat cells as a child if you are overweight and then they will always be there.”

“There is no miracle cure,” says Matthew. “And the problem is that all these different types of diet add to the confusion of what we should eat and how much.

Stress in schools could be producing a generation of children primed for obesity

“It all comes down to a balance between nutrition and activity levels.” (See separate story on the psychology behind obesity).

The stresses and strains of modern life must bear some of the blame for the Western world’s obesity epidemic.

That’s the view of Dr Kiara Lewis, Head of the Division of Health and Wellbeing at Huddersfield University, who says: “The latest thinking is that it’s not enough to make individual lifestyle changes, we need to change the environment we live in. There are so many cues to eat and options available; takeaways and fast food outlets. In the past we had to work hard for our food, today it’s easy to get and appetising. Calorie dense foods are satisfying. At the same time we are increasingly under a lot of pressure and stress; we eat to make us feel better about ourselves and we’re not thinking long term.”

Kiara is a member of Everybody Active, A Kirklees organisation that has the aim of raising activity levels by 2020. She says even children are vulnerable to stress-induced over-eating: “A lot of my research is with child obesity. If children are unhappy, stressed and worried then food can make them feel comforted. They have enormous pressures on them at school to reach targets and standards. Stress makes people want to eat, then they get fat and feel bad about it. It’s a vicious circle. Schools could do more about tackling the whole welfare of the child, not just worrying about maths and English.”

One third of all UK children aged between two and 15 are overweight
One third of all UK children aged between two and 15 are overweight

Given that individuals don’t have the power to close down fast food outlets or change the way high-calorie foods are marketed and sold, what steps can those with weight worries take? Kiara says there are a few simple, evidence-based measures - reduce portion sizes; set a target or goal; monitor what you eat; get feedback from a third party. But in order for these to work, an individual has to be motivated or ready to make changes.

Slimming clubs work on the principles of target-setting, monitoring and feedback. But says Kiara: “There is evidence that this works in the short term, the problem is that what hasn’t changed is the environment around you. What we need is for the whole of society to change.”

Another difficulty for many slimmers is that their own body chemistry makes them more likely to over-eat. “Some people feel full up quickly, others don’t,. There isn’t a fat gene per se but there are genes that make you want to eat. These people will find it more of a struggle,” she added.

And, while exercise can be hugely beneficial she accepts that for those already overweight it can also be uncomfortable: “Exercise can relieve stress but it’s not easy for some people to start. They think it’s going to be painful and horrible. We encourage inactive members of the community to get out walking and do small amounts of activity but get into a routine; to make a start.”