Slimming World Under the Spotlight
Slimming World Clubs Review

With more than 6,000 group classes held each week, Slimmingworld is one of the largest slimming clubs in the UK. But how easy is the diet and is it one of the few ‘diets’ that do work? Dietitian, Juliette Kellow BSc RD finds out more.

Slimming World Under the Spotlight

By Dietitian, Juliette Kellow BSc RD

Slimming World is certainly a big name in the slimming industry and with a 40-year history it’s stood the test of time.

The club was created in 1969 by Margaret Miles-Bramwell, who today remains the chairman of the organisation.

At the time, Margaret was struggling to lose weight but found there was little support to help overweight people like herself.

Her vision was to devise a healthy eating plan that would prevent hunger, and combine it with a support group to help, amongst other things, to raise self-esteem.

The rest, as they say, is history. Four decades on and Slimmingworld has more than 6,000 clubs with 2,500 consultants in the UK.

Around 300,000 people attend a Slimming World club each week and it’s estimated that group members lose a total of 2,551 stones every day!

They’re impressive statistics and so it would seem the diet certainly works. But just what does it entail and can it help you keep the weight off afterwards? We delve deeper…

How Does The Slimming World Diet Work?

Slimming World is basically a slimming club that combines a unique diet plan with group support.

To gain access to the diet, you need to become a member. You can also become a Slimming World online member and receive the diet information this way.

Tell Me About the Slimming World Diet?

Slimming World’s unique plan is called Food Optimising. The theory behind the plan is simple – to lose weight you need to take in fewer calories than you use up.

Food Optimising achieves this reduction in calories by encouraging dieters to freely eat foods that are lower in calories but high in nutrients such as pasta, lean meat, rice, fish, fruit and veg, whilst limiting calorie-packed foods that are nutrient-poor such as biscuits and booze.

Because the focus is on eating mainly lower-calorie foods, Slimming World claims that its Food Optimising diet lets you eat as much as you like, without having to count calories or constantly weigh or measure food.

All the information about Food Optimising is provided in a book that’s part of the joining pack you receive when you become a member.

So How Does Food Optimising Actually Work?

The diet has three steps:

Step 1 – Choose Free Foods

Slimming World provides detailed lists of foods that can be eaten in unlimited quantities.

Fresh fruit and most veg are classified as Superfree Foods because they are so low in calories.

Free Foods include lean meat, chicken, fish, potatoes, rice, pasta, grains, pulses, starchy veg, eggs, fat-free dairy products, Quorn and tofu.

Within Free Foods, there are three choices available: the Extra Easy choice; the Green choice (sometimes known as a Green Day); or the Original choice (a Red Day).

You can mix and match these choices from one day to another or simply stick to the same one all of the time.

Step 2 – Choose Healthy Extras

In addition to Superfree and Free Foods, you are allowed Healthy Extras every day.

These vary according to whether you are following the Extra Easy, Green or Original plan.

Step 3 – Choose Syns

Syns is shorthand for synergy – Slimming World believes it’s the synergy between the three components of the plan, ie. Free Foods, Healthy Extras and Syns, that makes Food Optimising effective at enabling weight loss.

Nevertheless, many of the Syns are effectively what other diet plans would call ‘treats’.

But Syns also includes foods found in the Healthy Extras, allowing you to eat bigger portions of these foods if you want them.

Regardless of the plan you choose to follow, you are allowed five to 15 Syns a day.

These include foods like biscuits , cakes, crisps, dressings, alcohol, ice cream, preserves, puddings, pizza, chocolate and sweets.

The Syns value for some foods may vary depending on the plan you are following but as a guideline one Syn is equivalent to around 20 calories.

What Can I Eat With the Slimming World Extra Easy Choice?

You start by filling a third of your plate with Superfree fruit and veg, then add unlimited amounts of foods from the following:

  • beans
  • peas
  • lentils
  • bulgur wheat
  • couscous
  • potatoes
  • pasta
  • noodles
  • rice
  • eggs
  • Quark
  • fat-free cottage cheese
  • natural fromage frais and natural yoghurt
  • Quorn
  • tofu
  • lean meat
  • poultry
  • offal
  • fish

On top of this you choose one Healthy Extra from the A choices, which are mainly calcium-rich dairy products.

For example, a choice is 350ml skimmed milk, 28g Cheddar or 42g mozzarella.

Plus, you choose one Healthy Extra from the B choices, which tend to be higher in fibre and include wholegrain cereals, crispbreads and bread, dried, cooked and canned fruit, and filling soups.

For example, a choice is one wholemeal pitta, two slices of wholemeal bread from a small loaf, 28g wholegrain cereal or 71g dried apricots. Then you have your Syns on top of this.

What Can I Eat With the Slimming World Green Choice?

The Green choice focuses on more carb-rich foods and less meat, so is a better choice for people who follow a vegetarian diet.

Once again you start by choosing Speed Foods and then add unlimited amounts of Green Free Foods, which include beans, peas, lentils, bulgur wheat, couscous, pasta, potatoes, noodles, rice, eggs, fat-free natural yoghurt, fromage frais and cottage cheese, Quorn and tofu.

You choose one or two Healthy Extra A choices (low-fat dairy products) and two Healthy Extra B choices, the list of which is extended to include lean meat, poultry, fish, nuts, seeds and more cheeses.

For example, a choice is 57g cooked beef, 71g cooked chicken, 142g cod, 28g Edam or 28g houmous. Syns are added on top of this.

What Can I Eat With the Slimming World Original Choice?

The Original choice focuses on more lean protein-rich foods and fewer carb-rich foods.

You start by filling up on Speed Foods then add unlimited amounts of Red Free Foods, which include lean meat, poultry, fish, eggs, fat-free natural yoghurt, fromage frais and cottage cheese, Quorn and tofu.

You choose one or two Healthy Extra A choices (low-fat dairy products) and two Healthy Extra B choices, the list of which is extended to include beans, lentils, wholewheat pasta and potatoes.

For example, a choice is 142g baked beans, 100g cooked wholewheat pasta or a 227g baking potato (raw weight). Syns as always, are added to this.

Slimming World's Principles

Isn’t This a Version of Food Combining?

No. Food combing doesn’t allow carbohydrate- and protein-rich foods to be eaten in the same meal.

Whichever plan you follow on the Food Optimising programme, you are still allowed to eat carbs and proteins in the same meal – it’s just that you might eat smaller amounts of one or the other in order to help you lose weight.

Does Slimming World Consider Exercise at All?

Yes. Slimming World has a programme called Body Magic that’s designed to encourage members to become more active.

It focuses on encouraging members to do 30 minutes of activity five times a week, which is in line with government advice.

As well as receiving a booklet on Body Magic when you join, exercise advice is provided in the weekly group sessions.

You also receive weekly log sheets that enable you to set aims for the week, set daily and weekly goals, recognise danger areas and record your activity levels on a daily basis. As you become more active you receive, bronze, silver, gold and platinum recognition.

Is There Anything Else I Should Know About?

As well as Food Optimising and Body Magic, SlimmingWorld has devised a concept called IMAGE therapy, which stands for Individual Motivation and Group Experience.

In reality, this refers to the group support that members can expect to get by attending weekly meetings.

Like most support networks, the meetings aim to provide encouragement, inspiration, motivation, empowerment and positivity.

Members share ideas, recipes and stories, are encouraged to make weekly commitments and plan ahead, and if necessary, consultants offer one-to-one-support throughout the week.

A Commitment course of 6-12 weeks is also offered at an extra fee, the support is offered through weekly meetings. 

These courses are designed to boost motivation and during times that might be a littlemore difficult such as holidays and Christmas. 

Are Group Leaders Trained?

Group leaders, who are known as consultants, are all previous, successful group members.

take a four-day course that includes training on Food Optimising, Image Therapy, Body Magic and SlimmingWorld on Referral (see below).

They then take four diploma examinations that test their knowledge of how to run a group, how to motivate members, their understanding of Food Optimising, basic nutrition and food facts, and the role of exercise in weight management.

A Foundation Diploma is then awarded.

Slimming World Consultants receive specific training in dietary aspects of weight management, the role of physical activity in weight control and importantly, advanced training in behaviour change.

The training is supported by a team of registered nutritionists and dietitians at Slimming World’s Head Office.

Will Everyone at the Slimming World Club Know my Weight?

Slimming World promises your weight won’t be disclosed to other group members. Only your weight change is revealed each week.

Is There Support Available Outside of the Club?

Slimming World has a free website for SlimmingWorld members called LifelineOnline.

It’s available to members 24 hours a day, 7 days a week and provides recipes, a personalised progress chart and an interactive food diary.

You can also get support from Slimming World members who have agreed to be phone, text or email buddies to members from their group.

How is my Goal Weight Set?

You are allowed to choose your own target weight, which is referred to as your Personal Achievement Target.

There’s no pressure to set a target weight within the healthy Body Mass Index range of 20-24.9.

However, you are not allowed to set a target weight that’s below a BMI of 20.

What Happens When I’ve Reached my Goal?

You can continue to go to Slimming World Clubs for free providing you stay within 3lb of your target weight, regardless of what that is.

Can I Follow the Slimming World Diet Without Going to a Club?

Slimming World offers an online diet programme where you then have access to the Food Optimising plan, a Syns calculator, recipes and menu plans, a progress chart, an online food diary and activity programme.

How Much Weight can I Expect to Lose?

As the Slimming World diet is based on healthy eating, you can expect to lose, on average, 2lb a week. Exercising regularly will boost this weight loss.

Can Anyone Join?

In order to become a member, you must have at least 7lb to lose. People with diabetes may join but they must let their consultant know they have this condition.

There is also a programme for children aged 11-15 years called Free2Go, which focuses on encouraging children to eat more healthily rather than on losing weight.

This follows the basic principles of the Food Optimising plan – children fill up on Free Foods, add Healthy Extras and eat fewer fatty and sugary foods.

Children can attend SlimmingWorld clubs free of charge when they go with a paying adult or guardian, but they must have the approval of their GP or practice nurse by providing a signed consent form.

Pregnant women and new mums can also attend. Slimming World has devised a programme for pregnant and breast-feeding women in conjunction with the Royal College of Midwives to help them manage their weight.

To be a member whilst you are pregnant, you need to have the signed consent of your midwife. For the online service, people with cancer, liver or kidney disease or an eating disorder are not allowed to join.

Are Health and Diet Experts Supportive of Slimming World?

SlimmingWorld works closely with experts and organisations in the obesity field and also funds research in the area of weight management.

As a result, it has the support of many health professionals.

In 2003, the Slimming World on Referral scheme was launched. This scheme, which is subsidised by Slimming World, means that GPs can ‘prescribe’ attendance at a Slimming World club for 12 weeks free of charge.

The scheme is currently offered by more than 50 Primary Care Trusts across England.

However, many health organisations such as the Department of Health and the Food Standards Agency are now focussing on encouraging us to better control our portion sizes.

Therefore the idea of eating huge amounts of Free Foods – even though they are healthy – is likely to be in conflict with this.

How Much Does it Cost to Become a Member?

The one off joining fee is £10. You then pay £4.95 for each weekly meeting (£4.65 for senior citizens).

Children aged 11-15 years old can attend for free if they come with a parent or guardian who is a member. Otherwise, the weekly fee is £3.95 plus the initial joining fee (they still must attend with an adult).

The online membership fee varies depending on the level of service you opt for. There are three levels of service.

The Bronze membership costs £79.95 for a three-month subscription and includes three months online access.

The Silver membership costs £84.95 and in addition includes seven issues of Slimming World magazine.

The Gold membership costs £99.95 and includes Slimming World’s Food Optimising and Body Magic books as well as the standard Silver membership content.

There are frequently offers available for both the group and online memberships.

What are the Pros?

Food Optimising basically encourages healthy eating by recommending lots of fruit and veg, healthy carbs, lean protein-rich foods, low-fat dairy products and smaller amounts of fatty and sugary foods.

This means that whilst losing weight, members develop good eating habits they can follow for life – and will help to keep the weight off.

There’s also no need to cook different meals for yourself – all the family can eat meals based on Slimming World’s Food Optimising plan.

The concept of Syns also works to educate slimmers on those foods that are higher in fat and sugar and so should be limited – but at the same time allows them in small amounts so they don’t feel deprived.

It’s also good to see that exercise is considered to be an integral part of the programme.

And the Cons?

All of the Free Foods such as lean meat, chicken, fish, pasta, potatoes, rice, couscous, eggs and beans still contain calories.

For example, with the Easy Extra choice, in theory you could eat a spaghetti Bolognese designed for four people providing it only included Free Food ingredients such as wholewheat pasta, lean mince, carrots, onions, mushrooms, canned tomatoes, tomato puree and stock.

This could easily add up to 2,000+ calories (a large portion of wholemeal pasta contains 400 calories alone)!

As a result, it’s possible to eat sufficiently large amounts of Free Foods to take in enough calories to cause weight maintenance or even weight gain rather than weight loss.

Though Food Optimising claims there’s not much measuring needed, you’ll still need a pair of accurate food scales as all the Healthy Extras and Syns are given in weighed amounts.

Unfortunately, most of the weights aren’t in consumer-friendly amounts either, for example, 57g of cooked pork, 71g canned salmon or 113g chickpeas.

You’ll need very accurate scales that measure to 1g to get this level of accuracy.

Juliette’s Verdict

As a newcomer to the plan, the diet seems very complicated and incredibly daunting.

You need to spend time working out exactly what you can eat freely and get to grips with the Extra Easy, Green and Original choices, together with the Healthy Extras and Syns.

Fortunately, there’s a 7-day plan based on the Extra Easy choice to help you out.

Food Optimising

I like the fact Food Optimising encourages a healthy, balanced diet and doesn’t ban any foods.

However, whilst I support the concept of limiting fatty and sugary foods, I do think using the term Syns has a negative meaning within a plan that is otherwise very positive.

Syns might stand for Synergy but the term still infers that certain foods are ‘sinful’ and therefore reinforces the idea that they are ‘naughty’ or ‘bad’ for us.

As a result, we are more likely to feel guilty when we’ve eaten them – something that contradicts Slimming World’s mission to promote guilt-free eating.

Free Foods

When it comes to the claim that you can eat as much as you like, for successful weight loss, it’s important not to take that to the extreme.

Indeed, if some people did eat as much as they liked of the Free Foods, they could potentially end up gaining weight rather than losing it.

This means you still need to exert some degree of control when it comes to serving sizes, no matter what the Slimming World literature says.

Like many health experts, I think it’s crucial that people start to have a better understanding of what constitutes a suitable portion size to help them control their weight.

This includes portion sizes for foods like meat, pasta, rice and potatoes. For example, a suitable portion of meat should be about the size of a deck of cards, a portion of rice or pasta should be about the size of a tennis ball, and a potato should be about the size of a computer mouse.

Slimming World does nothing to educate slimmers about the sort of portion sizes they should really be aiming for, potentially making it more difficult for slimmers to keep the weight off once they start to relax their diet a little more and include more ‘Syns’.

Household Measures

As for the foods that need to be weighed, I would prefer to see more household measures being used, or at least guidance on weighed portions to the nearest 10 grams. This is far more practical.

The online service is very comprehensive with plenty of good advice and some features.

However, there isn’t much opportunity for online members to interact with each other, such as the provision of chat rooms, although comments from members are welcomed and posted at the end of features.

I like the fact that Slimming World as an organisation works with health professionals – the Referral Scheme is a great idea.

Providing a plan that enables pregnant and breast-feeding mums to manage their weight is also a positive move as this is a time when weight problems often start for women.

The children’s plan is also a fabulous idea considering so many teenagers are now overweight or obese – the only downside is the stigma attached of going to a ‘slimming club’.

No Magic Wand

All in all, there’s no magic behind the Slimming World diet. Ultimately, it’s a plan that helps you to reduce your calorie intake so that you shift those pounds.

Whether or not you want group support to help you on your way is a personal thing – whilst some people benefit massively, others may shy away from the idea of talking about their weight problem with others.

In conclusion, as WLR members will already know, to shift those pounds you need to change your eating habits and focus on eating healthy, nutritious and lower-calorie foods whilst having fewer fatty and sugar foods.

Slimming World’s Food Optimising plan has the potential to help you achieve this, providing you can get to grips with what you can and can’t eat and remember that Free Foods still contain calories and so shouldn’t be eaten in supersized amounts.

WLR members that have tried Slimming World


I have done Slimming World more than once - and quite frankly I get bored very quickly because I find it hard to eat out or be spontaneous with it. OnwardsandDawnwards

I have always done Slimming World, and you can eat loads of carbs with out counting the calories... however it was not working for me!! Keegan

I did Slimming World a couple of times a few years ago and never had any long term success with it. The sysn were confusing and my portion size perception actually worsened. Since I joined WLR and stuck to calories control, I've lost more and kept it off for far longer hen with any other method.  Extremeweazle

I tried Slimming World about 18 months ago and was reasonably successful losing just over 2 stone. However, my weight loss flatlined and I lost interest. Consequently my weight has crept up again. TradCat

I did Slimming World for month and was always thinking about my next meal and obsessed with what I couldn't have. Didn't lose anything. Hated staying for the roll call of shame too. Think it does work for some, but I can honestly say that I'm enjoying eating normally and managing to lose weight without cottage cheese, low fat yohurts and skimmed milk. Silversurfer

I've used Slimming World - it's expensive and if you do manage to lose weight on it, you simply go back to the previous way you are and regain the weight, plus more! Pineapple27

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