New BBC series investigates the science behind the latest diet research
Three-part Horizon programme marks one of biggest studies of diets in UK
75 overweight volunteers are put through a series of tests to discover why they eat too much and why they are overweight
Split into three groups to follow tailored diets – the Feasters Diet, the Constant Cravers weight loss plan and the Emotional Eaters diet
What Is The Right Diet For You starts tonight on BBC 2 at 9pm
It is a question that has long occupied the hungry minds of millions hoping to lose weight – what is the best diet to help shift the pounds?
A plethora of mantras adorning bookshelves, a constant stream of celebrity-endorsed plans bursting with promises of quick weight loss, and a flurry of new ‘superfoods’ each week, makes the journey to slim down a confusing one.
But a new three-part BBC series aims to offer the answer tonight.
One of the biggest studies of its kind in the UK, the programme investigates the science behind the latest diet fads.
What Is The Right Diet For You, a Horizon series, sees a team of experts considering the effect of biochemistry, psychology and genes on weight gain.
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Instead of buying into the latest dieting fad, the scientists found the only way to successfully lose weight is to use a personalised diet, built around an understanding of a person’s individual biology and specific needs.
Professor Tanya Byron, a clinical psychologist with 25 years experience, said the study used cutting edge science from Cambridge University to develop tailor-made weight loss plans for 75 overweight volunteers.
The dieters firstly took part in a complex screening process to establish a range of things, including the levels of a specific gut hormone, as well as each person’s genetic make up.
They were then split in to three groups, and given a tailor-made diet to follow for three months.
Professor Byron told MailOnline: ‘Some we found were emotional eaters, those who used emotional coping mechanisms.
‘Then there were people with low levels of the gut hormone GLP-1, which signals the brain, telling it a person is full.
‘They were known as the feasters, who don’t necessarily eat all the time, but when they do, they find it hard to stop.
‘And the third group, the constant cravers, were those whose genes drive them to eat. They are more grazers, they don’t eat huge amounts in one sitting.
‘We spent a lot of time examining the results of the screening, conducting further experiments to test different factors that affected the results, to make sure the categories were correct.’
A new three-part BBC Horizon special investigates the science behind the latest diet fads, helping separate 75 overweight volunteers into three categories: Emotional Eaters, Constant Cravers and Feasters
WHAT KIND OF EATER ARE YOU?
Emotional Eaters
Emotional eaters are those people who eat for psychological reasons, turning to junk food when they are anxious, depressed or stressed.
Studies have shown that the most effective way to lose weight for emotional eaters, is to attend a weight loss group.
The groups will supply a diet plan of low-fat, calorie-controlled recipes to follow.
For emotional eaters the support of fellow dieters is a powerful tool, helping drive weight loss. And the impending weekly weigh in helps in moments of stress, when a person might be tempted to break their diet.
Feasters
When most people eat, a specific hormones in our gut send a strong message to the brain, telling the brain the stomach is full.
But if a person is a feaster, scientists believe they produce less of the gut hormone, GLP-1.
It means the signal telling a person to stop eating is weaker.
To lose weight, feasters need to eat certain foods that help boost the production of gut hormones.
A diet high in protein and low glycaemic index (GI) carbohydrates has been found to encourage production of the vital hormones, and increase feelings of fullness.
Constant Cravers
Constant cravers feel hungry most of the time.
Scientists believe this factor could indicate a person has more of the genes that tend to make you feel hungrier. This increases the likelihood of eating too much and gaining weight.
Because constant cravers are constantly hungry, it is hard to sustain the effort to reduce calorie intake every day. So the diet involves two restricted days, where a person will limit their calorie intake to no more than 600-800 calories a day, with virtually no foods or drinks containing carbohydrates.
The other five days are unrestricted, meaning a person does not need to count calories or limit carbohydrates, but must eat a healthy Mediterranean-style diet.
Personalised diet plans were then designed for each group, based on each of the three profiles.
Emotional eaters were encouraged to join weight loss groups and received Cognitive Behavioural Therapy.
‘I did a lot of work with this group,’ Professor Byron said. ‘In tonight’s programme you will see us abseilling down a light house.
‘The idea was to get them past the “I cant do this”, “I am a failure” way of thinking about dieting, and show them if they can abseil down a building, they can do anything.’
Dr Chris Van Tulleken, an infectious diseases specialist from UCL, focused on working with those volunteers in the Feasters and Constant Cravers category.
The Constant Cravers were put on an intermittent fasting diet, with two days of low calorie intake and healthy eating for the remaining five days.
And for Feasters, their diet was designed to maximise the production of the GLP-1 hormone, and promotes eating foods that are digested in that part of the gut.
Professor Byron told MailOnline the study, which is among the first of its kind, far exceeded the scientists’ hopes.
‘All the volunteers did unbelievably well, they exceeded our targets set for three months, which was that they would lose five per cent of their weight in that time.
‘It was an incredible experiment, that was about helping people understand themselves better, to generate more understanding of their behaviours.
‘You are more likely to be able to change your behaviour to lose weight and maintain your weight loss.
‘It was about giving people the information and helping them use it to change their behaviour and lifestyle.’
Dr Van Tulleken added: ‘One of the biggest things was trying to get away from the idea that fat, overweight people are lazy.
‘There are huge numbers of biological factors outside people’s control, like hormones or genes, that means it can be harder for some people to lose weight.’
But rather than give people an excuse for why they are overweight, Dr Van Tulleken told MailOnline the study actually empowers people to understand their bodies and learn the best way to shed pounds.
A team of experts worked with scientists from Cambridge University to screen the 75 volunteers looking at how their biology affects weight gain. The tests looked at levels of a gut hormone GLP-1 and each person’s genes to try and establish the best way to help each individual shed pounds
After being split into the three groups, the volunteers were given a tailor made dieting plan to follow for three months. Emotional Eaters were advised to join weight loss groups and were given Cognitive Behavioural Therapy, Constant Cravers were put on an intermittent fasting diet with two days low calorie intake, while Feasters were put on a high protein, high low GI carbohydrate diet
Dr Chris Van Tulleken, third from right, and Professor Tanya Byron, second right, said the study exceeded their expectations. They told MailOnline the key was to help people understand their biological make up, to follow diets that they are more likely to be able to maintain, by changing habits and creating new behaviours
‘When people understand the biology of any medical problem, it empowers them to deal with it,’ he said.
‘Almost every person has, at some point, tried to lose weight, most will have failed or lost the weight and put it back on.
‘The message is that any diet will work if you stick to it,’ Dr Van Tulleken said.
‘This study was about trying to identify those people a diet that they will find it easier to stick to.
‘It is about building new habits and changing behaviours.
‘Like if you are trying to learn a new foreign language, it is difficult because if it doesn’t come with the lifestyle advice, it will be hard to achieve.
‘It is not about willpower. No one can will themselves thin but you can create a life environment to help you lose weight.’
What Is The Right Diet For You, a Horizon special, will air tonight, Tuesday and Wednesday on BBC 2 at 9pm.
