What Is the Slimming World Diet?

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Slimming World is a popular weight loss program based in the United Kingdom. Now available for customers in the United States until recently, the plan teaches members to shop for and eat whole, nutritious foods and limit their intake of fatty, sugary, or processed foods. Motivational support and guidance to encourage an active lifestyle are also vital components of the program.

What Experts Say

"The Slimming World diet promotes weight loss via filling 'free foods' and small treats. There is little emphasis on portion control of 'free foods,' though. While pasta and potatoes have a role in a balanced diet, experts agree the emphasis on unlimited amounts isn’t ideal."
Chrissy Carroll, RD, MPH


Slimming World was founded in 1969 by Margaret Miles-Bramwell, a British woman who struggled with the frustration and guilt of failed weight loss attempts. The program was only available in the UK until 2016, when Slimming World USA came to the United States.

Slimming World is for consumers aged 18 and over with a BMI of 23 or above. A normal BMI for adults is considered to be 18.5–24.9, according to the U.S. Centers for Disease Control and Prevention.

The Slimming World program is based on the belief that confidence-building support and healthy food choices can produce weight loss without counting calories or severely restricting food intake.

To follow the program, customers sign up for a membership (roughly $10/month) that gives them access to a weekly support meeting and other resources that help them to build meals and practice daily habits that boost weight loss.

How It Works

A Slimming World membership includes three key components: a food plan, a support plan, and an activity plan.

What to Eat

Compliant Foods
  • Fruits and vegetables

  • Lean meats

  • Fish and seafood

  • Pasta, rice, and potatoes

  • Eggs

  • Legumes

  • Cooking spray

Non-Compliant Foods
  • Milk and cheese (in excess)

  • Cereal and bread (in excess)

  • Treats like baked goods, ice cream, and wine (in excess)

  • Nuts and Seeds (in excess)

  • Avocado and oils (in excess)

Slimming World members practice "food optimizing" to avoid hunger and stay satisfied. Food optimizing means building meals around foods that fall into one of three categories including free foods, healthy extras and "syns."

Free Foods

Members do not measure or restrict these foods. Free foods include lean meat and poultry, fish and seafood, potatoes, pasta, rice, eggs, beans and lentils, fruits and vegetables, and other foods that are low energy dense (low in calories). 

Keep in mind that some of these foods are considered free foods for this specific diet, that they are not low in calories and should be portion-controlled. Some free foods are considered "speed foods," and members are instructed to include a certain number of speed foods in each meal. Speed foods are foods that are lower in calories but high in nutrition (like many fruits and vegetables).

Healthy Extras

Members will need to measure and limit foods in this category. Healthy extras include calcium-rich foods, such as cheese, yogurt, and milk, and fiber-rich foods such as whole grain cereal, and whole grain bread products. These foods provide nutrition and boost satiety, but increase daily caloric intake. Healthy extras are enjoyed in smaller amounts.


These are foods that some might call indulgences. Syn stands for "synergy," and the word represents all of the treats that bring us enjoyment and help us to stay on track with our diets. Syns include foods like sugary baked goods, candy, ice cream, or wine. This category also includes cooking oils, like olive oil and other healthy fats like avocado. These foods make up the smallest proportion of the diet.

Resources and Tips

A key component of the Slimming World plan is community support, offered through meetings and online tools. During the first 12 weeks of the program, you'll have access to a structured program that helps you learn about the eating plan. You will also sign up for an online "Slimming Group" that meets at a time that is convenient for you. Participation in the Slimming Group is the cornerstone of this program.

According to a company statement, "the program is built upon a deep understanding that people who are overweight carry a double burden: The burden of weight itself and the far heavier burden of guilt, self-criticism, and low self-esteem."

For this reason, members support each other during the one-hour meeting where the focus is on growing self efficacy and building confidence. Each session is directed by a Slimming World-trained consultant. Before each session, members may choose to log their weight change.

No one is required to reveal their progress or their weight to the other group members. However, if they do so, they can expect to get support and feedback regarding their success or struggles. Questions are answered during the meeting and members share tips to help each other stay on track.

Slimming World Activity Plan

Although physical activity is strongly encouraged, exercise is not required on the Slimming World plan. In fact, the company believes exercise is not required to lose weight. But they encourage members to boost daily activity to help with weight loss and to keep weight from coming back.

To increase physical activity, Slimming World promotes Body Magic, its program to burn more calories by incorporating more movement into your daily routine. The program was developed in collaboration with Ken Fox, emeritus professor of exercise and health sciences at the University of Bristol in England.

As a Slimming World member, you'll use evidence-based strategies to gradually increase daily movement and build your own sustainable activity plan. The goal of the program is to eventually participate in 150 minutes of moderate intensity activity per week.

Members get an online interactive activity planner that comes with a series of rewards and are encouraged to explore physical activities that they already enjoy.


Those who have certain medical conditions, such as high cholesterol or diabetes, may use the plan with guidance from a physician. Vegan and vegetarian eaters will also find support on the Slimming World diet. The program is not recommended for women who are pregnant or anyone with an eating disorder.

Pros and Cons

No diet or weight loss program works perfectly for everyone. So before you choose to invest in any commercial program, it's smart to evaluate the pros and cons of the program.

Ask yourself key questions about your lifestyle, your budget, and your past dieting history to make sure you choose this program will work for you. Here's an overview of the pros and cons of Slimming World.

  • Lists no restricted foods

  • Contains no calorie counting

  • Requires no special foods or supplements

  • Includes support

  • Provides little portion control

  • Requires a lot of time


Offers Wide Variety

No foods are off-limits on this plan, but many of the foods that are emphasized are nutritious and recognized by most health experts to be important for a healthy diet. They are also foods that are likely to help you feel full after eating so you don't get hungry.

Contains No Calorie Counting

Unlike many popular commercial diets, there are no packaged foods to buy, no shakes or meal-replacement drinks, and no specific calorie goals to meet on the Slimming World diet.

Includes Community Support

Access to a Slimming World consultant and to fellow members is built into the program. Support like this can make a big difference. Several studies have supported Slimming World as an effective weight loss program.

For instance, a study published in BMC Public Health evaluated weight change outcomes in 1,356,105 adult participants during their first three months of participation in Slimming World.

Researchers reported the average amount of weight loss was approximately 8.5 pounds, with average attendance reported at 7.8 sessions. For participants attending at least 75% of possible weekly sessions, average weight loss was nearly 15 pounds.

A study published in the Journal of Human Nutrition and Dietetics evaluated 67 male members of Slimming World and found that men who were members for 12 weeks lost an average of 9.2% of excess weight and at 24 lost an average of 10% of excess weight.

Note that most of the published research findings and statistics are funded by the company and/or conducted by the Slimming World research team. Additionally, while these benefits are encouraging, there are also some drawbacks to Slimming World. Prospective consumers should be aware of these.


Offers Little Portion Control

The Slimming World program has been criticized by the National Health Service in England for not providing enough information to members about calories and portion sizes.

Even though the program promises that you don't have to measure foods, count calories, or eliminate certain foods, there are rules you need to follow if you want to be successful. So it is realistic that you may feel deprived or struggle as you adjust to eating new foods and limiting or avoiding certain comfort foods that are not on the free foods list.

Requires a Time Commitment

While the foundation underlying Slimming World's food, support, and movement plan is sound, the program may take more work than other popular commercial programs like Jenny Craig or Nutrisystem.

No foods are provided, so members must learn to prepare their own meals and make numerous food choices throughout the day. For some, this approach may be overwhelming. In simple terms, this program doesn't provide the convenience or flexibility offered by other weight loss systems.

In addition, members need to have access to reasonably healthy goods and services for this program to work.

If you don't have a market nearby where you can purchase nutritious food, and if you don't have time to prepare meals, you may have a hard time sticking to the plan.

You also need to find the time and energy to create a program to increase daily movement for the activity plan to be effective.

How It Compares

The Slimming World program is designed to support weight loss at a rate of one to two pounds per week. Most experts agree that this is a reasonable and sustainable rate. This diet shares some similarities with other popular commercial weight-loss programs.

Food Groups

The structure of the Slimming World eating plan follows similar guidelines as the USDA's Choose My Plate program, which encourages Americans to fill their plate with vegetables, fruit, whole grains, and lean meat.

Additionally, the program encourages dieters to limit their intake of empty calories and to fill up on satisfying whole foods (with an emphasis on fruits and vegetables) to promote wellness.


The Slimming World program differs from USDA recommendations in one key area—calorie counting. Slimming World doesn't require it, but the USDA (and many nutrition experts) suggests that being mindful of calorie intake may be necessary for weight loss. This calculator will help you determine about how many calories you should consume every day to reach a goal weight.

Similar Diets

Several other commercially available diets use some of the same strategies that Slimming World does.

Slimming World

No foods or food groups are off-limits. Instead, foods are divided into three categories—free foods (unlimited); healthy extras (allowed in moderation); and syns (to be eaten sparingly).

In general, free foods are high-nutrient, low-calorie offerings such as fruits, vegetables, and lean proteins. Some experts question whether starchy choices such as potatoes and pasta should be eaten in unlimited amounts (as they can be on this plan).

  • Support: Online support groups and coaching are included in the plan.
  • Activity: Exercise is recommended, and the program provides users with some suggestions for boosting daily activity.
  • Cost: Approximately $10/month, plus groceries.
  • Practicality: Limited measuring and tracking of foods can make this diet easier to follow, but users will still need to put time and energy into changing their lifestyle and daily habits.

Weight Watchers

Like Slimming World, Weight Watchers has its own system of encouraging certain foods and discouraging others, without banning anything outright. Users track SmartPoints instead of calories, and there are many zero-point foods (e.g., most fruits, vegetables, and many lean proteins).

  • Support: People on Weight Watchers can go to in-person meetings and/or join a virtual community of fellow users.
  • Activity: The Weight Watchers program also recommends exercise, and allows users to bump up their SmartPoints budget with activity points.
  • Cost: Approximately $20/month, plus groceries.
  • Practicality: Weight Watchers is designed for slow, steady, sustainable weight loss. Using the WW app to track points is easy, and there's no need for calorie counting or special foods.

Jenny Craig

Jenny Craig plans encompass both pre-packaged meals and snacks purchased through the company, and fresh food from the supermarket. The Jenny Craig products are portion- and calorie-controlled, and foods that users supply are limited to fruits, vegetables, and low-fat dairy products.

  • Support: People following the plan are paired with a Jenny Craig consultant who provides support and advice (but is usually not a trained nutritionist).
  • Activity: Recommendations for exercise aren't included.
  • Cost: From $550 to $800/month for food, plus program fees and grocery costs.
  • Practicality: Using pre-packaged food can make this diet easier to follow, and adding your own fruits and vegetables gives you a start on learning how to eat nutrient-dense, low-calorie foods. But it's tough to participate in a program like this for the long term.


With Nutrisystem, consumers receive ready-made, portion- and calorie-controlled meals. These are designed to be nutrient-dense and low in calorie. Consumers can also add their own fruits, vegetables, low-fat dairy products, and lean proteins.

  • Support: Online support is included with all Nutrisystem plans, and some plans also include an on-call counselor.
  • Activity: The plans don't include exercise recommendations.
  • Cost: Depending on the plan, $265 to $600 per month, plus some grocery costs.
  • Practicality: Since the shopping and cooking is mostly done for you (at a price), it's generally simple to follow this diet; there is little decision-making. However, Nutrisystem is not suitable for people with food allergies. And in general, meal-delivery services are not sustainable for the long-term. Following the Nutrisystem diet won't help you learn how to choose and prepare your own portion- and calorie-controlled meals.

A Word From Verywell

Many diet experts would argue that the key to sustainable weight loss is a strong personal commitment to healthy living and a foundation of nutritious food choices. So if you have the time and energy to learn about smarter eating, and if you have the motivation to build and sustain a pattern of daily movement, Slimming World may be a smart program for you.

Keep in mind that the weight loss program you choose may not be the most popular plan, or the plan that has worked for your friends and family members. But if it is an eating and lifestyle plan that works well with your daily routine, it's more likely that you will be able to stick to it long enough to see results on the scale and then adopt a maintenance plan to keep the pounds off for good.

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Article Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. About Adult BMI. Updated August 29, 2017.

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  4. National Health Service. Slimming World diet.

  5. U.S. Department of Agriculture. ChooseMyPlate.